Interaction of bioactive compounds with highly disperse oxides in aqueous suspension
Interaction of polymers (albumin, gelatin, polyvinylpyrrolidone) and some drugs with fumed silica in aqueous dispersions was studied using adsorption, NMR, photon correlation spectroscopy, electrophoresis and thermally stimulated depolarization methods. The impact of polymers on the structural and a...
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| Дата: | 2001 |
|---|---|
| Автори: | , , , , , , , , , , , |
| Формат: | Стаття |
| Мова: | Англійська |
| Опубліковано: |
Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2001
|
| Онлайн доступ: | https://surfacezbir.com.ua/index.php/surface/article/view/70 |
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| Назва журналу: | Surface |
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Репозитарії
Surface| _version_ | 1869291157500985344 |
|---|---|
| author | Gun'ko, V. M. Zarko, V. I. Turov, V. V. Vlasova, N. V. Voronin, E. F. Gerashchenko, I. I. Golovkova, L. P. Goncharuk, E. V. Leboda, R. Chibowski, S. Chibowski, E. Chuiko, A. A. |
| author_facet | Gun'ko, V. M. Zarko, V. I. Turov, V. V. Vlasova, N. V. Voronin, E. F. Gerashchenko, I. I. Golovkova, L. P. Goncharuk, E. V. Leboda, R. Chibowski, S. Chibowski, E. Chuiko, A. A. |
| author_institution_txt_mv | [
{
"author": "V. M. Gun'ko",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "V. I. Zarko",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "V. V. Turov",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "N. V. Vlasova",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "E. F. Voronin",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "I. I. Gerashchenko",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "L. P. Golovkova",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "E. V. Goncharuk",
"institution": "Інститут хімії поверхні НАН України"
},
{
"author": "R. Leboda",
"institution": "Maria Curie-Sklodowska University"
},
{
"author": "S. Chibowski",
"institution": "Maria Curie-Sklodowska University"
},
{
"author": "E. Chibowski",
"institution": "Maria Curie-Sklodowska University"
},
{
"author": "A. A. Chuiko",
"institution": "Інститут хімії поверхні НАН України"
}
] |
| author_sort | Gun'ko, V. M. |
| baseUrl_str | |
| collection | OJS |
| datestamp_date | 2018-11-27T09:42:39Z |
| description | Interaction of polymers (albumin, gelatin, polyvinylpyrrolidone) and some drugs with fumed silica in aqueous dispersions was studied using adsorption, NMR, photon correlation spectroscopy, electrophoresis and thermally stimulated depolarization methods. The impact of polymers on the structural and adsorptive properties of suspended-dried fumed silica was explored using nitrogen adsorption method with the regularization procedure. |
| first_indexed | 2025-07-22T19:30:03Z |
| format | Article |
| fulltext |
INTЕRAсTIONoFBIOAсTIVЕCoМPoI.INDsWITII
нIGIILY urspвкsЕ oхIDЕs IN AQUЕOUS sUSPЕI{sIoI{
V.М. Gun,kоl' V.I. Zarko|,V.V. Turov', N.N. Vla.soval, Е.F. Voroninl,
I.I. Gеrashсhenkol, L.P. Golovцo'u;,'Ё.v. сon"ьarukl, R. Lеboda2,
S. Сhibowski,, Е.СhibowsЬ2, and A.A. Chuikоl
IInstitutеofSuфcеСhеmistry,I7Ge.n.еrаlNаumovStrеet,03]61Kуiv,|JKRАINЕ
2Fаcultу of Сhеmistry, Mаriа Сuriе-Sklodo*'й i)п,,'itу:, zoоз t Lublin, PОLАND
Abstraсt
Intеraсtion of po1уmеrs (albumin, gelatin' polyvinуlpугг"ll99i? and somе drugs with
fumеd siliсa in aquеous disреrsions was studied u,rlй,.с'Jцi,rol, lI N.u{R ohоton сoгrеlation
speсtrosсopy, "t."t,opьllж;;;'й;l';;;i;;.J
J.pЬtu.i,ution. methods. Thе imрaсt of
polуmеrs on thе u..i",.i and adsoгpti* p.;;;i* oi suspеndеd-dгiеd fumed siliсa was
еxnlored uslng n'tro gе;;";й;;;ti.,oс *iь thе rеgularization proсеdurе.
lntroduсtionoispегsе
oхidеs suсh.as siri1 };yl1i:j]'1}1i#;;#l.llJ-'i'ъ1'}1i'.:т
sorbеnts or drug fillегs, additivеs and сaггiеr,.;;;;;"' of thеiг intеraсtion with dissolvеd or
immobilizеd drugs and thе сoгrеsponoing .mjТa
?."йr". thеir еffrсiеnсу. TШs intегaсtion
dеpеnds not onlу on pH or thе сonсеnt.u,ion? й.n .l".t'orytеs in a solution but aisо thе
availability oг .o*pouno ,, , ,,, protеin-s' iш..^.''g *i'r' ,ь. Ьxidе suгfacе morе еffесtivеlу
thanrеlativеlуsmalldrugйolесul:stlj?]Also'dгugsсanstronslvintегaсtwithsomе
biopоlуmегs, ,.g., .,uniiiiiig pгotеinr- ть.,"io*,' thе iivеstigation' Ъi drug intеraсtion with
the.o*idеsuгfaсе*.,i.in..o,?,'*-...Jr::*ir**",,Т'y#:#l"lffi Jъ".жуЬъff
ж*:l:::нжljl..'1ъxrЖff :x'ТЦ1Цi1xilT*.j"i::хуJ:Т:ilJx,"ъ"J:""
with diffегеnt sotio surгrс.,..i йi-i'.r "o,",р'iЕ"^"i;;A
;l HSA onto thе oxidе suгfaсе is
obsеrved ut pн
"ro,.
i-o*ii.i. i,o"i..tн. o"''ii.iiЫ;;й thе moleсulеs havе thе smallеst
;;"*-.'"il::#:";:,'*ж,',;i,**.o
Yli:1 ::.'',"^,"'""?.:,:'n.*'*.il:'1Т,:l;'(|s:3.":ii.
distгibutions (PSD),,.."^".o- u"blе. 1j d; ;;;"й ?ь., Ьа'o.p.ivе abilitу (tеstеd using
protеins) duгing u
"nЁ'uoй
oф"o ',11ti..ii""
Ьг.t'е oxidе suгface oг immobilization of
oo'Ymеrs on paпlсlr Ьu.',Ъ- ь. ,.,pon,ьi"..;;;
j-;;*s in thе hуdrogеn bond nеtwoгk'
i,..
"n.,gу
oг int.йujJ *u,.,, ,u.tЪ.. ;i;; distribution,
^elс,
whiсh сan affесt thе
dispеrsion stabilitу ;;;^ъ'i;;.;iaiaсtе,i*tiс,' Ъtuсу of intеraсtion bеtwееn fumеd siliсa
suspеndеd in watеr anJ di,,otu.d polуmers *i.ь
'ьЪi".ur
molесular sizе сlosе or largеr than
thatofpnmarystttсapaгtiсlеsisofi*.,"ц'.'.*".ь..o'pounds.сaninfluеnсеthedispеrston
stability, struсturе of paгtiсlе swarms, ,ь.orogi"u1 und othеr propегtiеs of thе siliсa dispеrsions
in diffегеnt li:#ъt/?;]
work was to studу ,..:y'i'-:l *r?::".l":;,Jloffi;1iio3ii.l'"'
polyvinуlpуггolidonе Ё*;; ,uь,titut"а."u,,";;;; drugs with thе suгГaсе of individual and
binary oxidеs *"n .JЬi.d silrсa' uru*i"u,iiiu"iu,-uiu*Тnы'lri.a and titania/siliсa dеpеnding
on pй unа thе сonсеntгatiоns ofthе сomponеnts'
310
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Ехpеrimеntal
Fumеd siliсa (Aегosil A-300, 99'5o/o puritу,^ and thе spесifiс suгfaсе aгеa (S3д1)
approхimatеly 3O0 m2 g.'),-fumеd alumina (s=150 .'g_'), fumеd titania ts=sо ', g-,i;;с
binary fumеd siliсa/titania (ST) at Сг,oz=9 (sT',20 1sizo), and З6 (5T36) wt7o 1s=iri, то,
and 90 *,g-,, rеsресtivеlу) and siliсa/alumina (SA) at С,lpoз=l28 (SAl), 3 (sAз), 23 (SAx)
and 30.6 (sAзl) wt% and 5=220, l80, l70 and 170 '' g-', геspесtivеly, and fumеd
Alzoз/Sioz/Тio2 (AsT) (-22 wtlh АJ2o3, э28 rrt.% Sioz, ry50 wt.% Тio2) (Pilot Рlant оfl
Institutе of SuгГaсe Chеmistry. Kalush, Ukrainе) wеrе usеd fог pгеpaгation of aquеous
susрensions. Foг initial susрensions, oxidе samplеs (ri,еighting 4 g) wеге stiгrеd with 200 ml of
distillеd Watеr duгing 48 h oг а wееk In addition' an aqueou, iuspеnsion of fumеd siliсa (6
wt%) trеаtеd in a ball mill duгing 7 h (mесhanoсhеmiсally aсtivatеd (iv{сA) suspension,1 lvaь
usеd. A]so' ball-millеd suspеnsion was aged duгing two months. Pгotеins BSA (Rеaсhеm),
HSA (Rеanal), gеlatin (phaгmaсeutiсal puпty, molесular wеighting -з +хt05), unа .jg
albumin (phaгmaсеutiсal puгitv, molесulaг wеighting o4.зх 10a) rvегe usеd as rесеivеd.
PVР (phaгmaсеutiсal puгity) (.СHzCHR-)", whеге R : Nс4tIбo, n t 100, molесulaт
wеight of |26ОО+2.700' was usеd as rесеivеd, P\T was addеd to thе aquеous suspеnsiоn of
siliса, ъ'Ысh thеn was tгеatеd in a ball mill duгing a fеw hours' In anothеr сasе, PVР was addеd
to thе agеd aquеous suspеnsion of siliсa' Thе ratio bеtwееn thеiг сonсеntrations Т.= СpldСs,oэ
was bеtwееn 0 and 1, Thе valuеs r < o.1 сопеspond to pгaсtiсallv iггеveгsiblе adsoгption ofP\P on thе siliсa suгГaсе [l] Additiоnally, P\? wаs usеd in thе phуsiologiсalbuffеr iolution
(PBS) with NaCl (5 5 g), KCl Ф a2 ф, СaCl2 (O 5 g)^ МgСl2 (O.0O5 g), uй шuнсo. (o.2з g)
peг litге of thе distillеd watег.
To еstimate thr amОunts of P\? stгоnglу bound to thе siliсa suгГaсе at | х Q |,
tеmpегaturе.pгogrammеd dеsoгDtion (TPD) of P\,{Р was регfoгmеd in aiг ovеr thе 293-|27з K
rangе using diffеrеntial thегmogгavimеtry (TPD-DTG) with a Q-l5O0D (Paulik & Рaulik)
DTG apрагatus' Тhе P\P/siliсa suspеnsion was сеntгifugalizеd at 8000 цpm, thеn thе
sеpaгatеd liquid was rеmоvеd and thе геsiduе of PVР/siliсa ц'as driеd at 33 j K. A majoг
dеsогption in thе TPD-DТG spесtгa was obsеrvеd ovег thе 550-850 K rangе, whеrе two
maхimа at -6l0 K and -770 K сoпеspondеd to PvP dесomposition. Thе amount of PVР
еstimatеd fгom thе ТРD-DТG data сoггеspondеd to 7 = 0'О94. A-ftег геpeatеd washing and
drying оf thе P\?/siliсa геsiduе, firstly dгiеd at 333 K, сalсulation of thе amount of PVP basеd
on thе ТPD-DTG data gaУe y = 0.092,, l.e., polymеr molесulеs wеге not washеd offpгaсtiсallу
fгom thе siliсa suгfaсе. Statistiсal monolayer сovегagе сoггеsponds tо 7: Q 18-0 l9.
Pгopгanolol hуdгoсhloгidе (Anapгilinе) is a nonsеlесtivе adгеnalinе bloсking соmpound
(noгadrеnalinе antagоnist)' Еthmosinе is an anti-arhythmiсal drug, whiсh inhibits thе
'Ьdiu'tгanspoгtation through thе sodium сhannеls in thе сеll mеmbranеs' Vегapamil hydгoсhloгidе is
a сalсium antagonist bloсking the ..siow'' сhanлеls with thе се1l mеmbгanе pгotеins t3b]. A]l
studiеd drugs usеd against thе hеaп disеasеs wеге studiеd in wеll-disioluble йrms of
hydгoсhloгidеs (l.e', сation foгms) as thе nеutral foгms arе pooгly dissolublе in watег. Thе
wavеlеngth of a maхimal UV absoгbanсе is 268 nm foг Еthmosine,278 nm (Veгapamil
hydгoсhloгidе) and 289 nm (Ргоpгanolol hydгoсhloгidе). Thе сonсеntration of dгuss
(pharmaсeutiсal purity) dissolr,еd in distillеd watег was mеasurеd spесtrophotomеtriсallу usin.g
a Speсoгd Ir,1-40 (Kaгl Zеiss, Gегmanу) sресtrоphotomеtег.
Aquеous suspеnsion of охidе (10 ml) and lO ml of drug solution wеге miхеd and thе
pH valuе was adjustеd by addition of О 1 М HCt oг NaoН soiutions to a dеsirеd valuе'
Thегеupоn thе suspеnsion was stiггеd foг i h' thеn оеntгifugеd at 50O0 гpm foг 15 min and thе
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сonсеntration of drug in sеparated solution was mеasurеd. Stеadу.state adsoгption of drug was
сalсulated from thе diffеrеnсе bеtwееn its initial and final сonоеntгations in thе solution. Thе
stеady-statе adsorption of albumin onto thе suгfaсе oГoхidеs was invеstigatеd by an analogous
tесhniquе. BSА' еsc albumin, and gеlatin wеге usеd to study thеir adsoгption onto oхidеs and
НSA was usеd upon simultanеous adsoгption with Vеrapamil onto thе siliсa suгfaсе.
N{еasuгеmеnts of thе pH valuеs of solutions and suspеnsions wеге pегГoгmеd using an
Ionometеr ЕУ.74 aрparatus bеfoге and aftег adsогptiоn. Тhе pH сhangеs duе to adsoгption
v7g1g +0.2 (protеins) and t0.O5 (drue9 Thе ultimate pH valuеs for thе еquilibrium statеs
(rеlativеly to adsoгption and pH valuеs) of thе oхidе suspеnsioт/ргotеin (drug) solution wеге
usеd in all гергеsеntеd dеpеndenсiеs of adsогрtion on pH,
Adsoiption of еgg albumin and gеlatin was studiеd without oхidе рrеtгеatmеnt and
with no additiоn of еlесtrolуte buffег solution' oxidе powdег (40 mg of oхidе pег 5 rrrl of
protеin solution) was addеd to protеin solution (0.6 Wt%) and adsoгption was mеasurеd after
Ь*po,u," foг houг (еnough to геaсh thе platеau adsoгption valuе) and thе suspеnsion was
сеntгifuged to dеtегminе adsoгption.
Photo,, сorrеlаtion Spеctrosсopу' Еlесtгophоrеtiс investigations wеге pегformеd using
a ZеtaPlus (Bгookhavеn Instrumеnts) ( potеntial apрaratus or a Zеtasizег 3000 (Мalvегn
Instrumеnts) aрpalatus basеd on the photon сoггеlation sрeсtrosсopy (PсS)' Deionizеd
distillеd rvаtег and diffегеnt amounts of oхidе pеr litrе of thе watег was usеd foг suspеnsion
prеpaгation in thе ultгasoniс bath for t* = l-9 h (frеsh suspеnsions) oг thе suspеnsions wеге
ultrasоniсatеd Гcг 5 min using an ultгasoniс dispегsеr (Soniсator Мisonix Inс ) (500 W'
frеquеnсу 22 kt1z) Тhе ball-millеd aquеоus susреnsions оf puге fumеd siliсa (5-6 wt. o/o) were
,tuii.d as obtainеd (agеd suspеnsions, as thе stoгagе periods wеге 1-3 months)' Thе ball-
millеd suspеnsions of P\P/silicawеге studiеd as prеparеd if Csioz< 6 wt Yo,but at Csioz= 6
wI..oА'thе suspеnsion was dilutеd bу half bеforе thе mеasuгеmеnts. Thе pH valuеs mеasuгed
Ьу a prесision digital pH-mеtег wегe adjustеd bу addition of 0.1 М HCl or NaoH solutions.
partiсlе sizing was сarгiеd out using photon сoггеlation spесtrosсopy (PCS) with a
Bгookhavеn ]\,LAS oPTIoN paгtiсlе sizег (aссuracу of +|-20k with monodispeгsе samples,
геpеatability of +I-Zok with dust frее samplеs). To сomрutе the paпiсlе sizе distгibutions
рЪоs;, D"f (avеragе hydгodуnamiс diamеtег, i'e., the paгtiсlе diamеtеr plus thе еlесtгiсal
doublе layег or thе doubiе shеaг laуеr thiсknеss: drcs : d,"ot - Аd at Аd - 2 к I
, whеге к is thе
Dеbyе-Huсkеl paramеter) and polуdispеrsitу (PD), thе Bгookhavеn ZеtaPlus Paгtiсle Sizing
softwaге (vегsiЬns 2'11 and 131) was utilized, assuming that paгtiсlеs wеге sphегiсal. To
сhaгaсtеrizе thе PSD unifогпrrtу, thе polуdispеrsitу valuеs сan bе usеd, and monodispеrsе
paгticlеs сoгrеspond to PD < 0.02, and PD = 0 02-0.08 rеpгеsеnts naггow distributions' Thе
tuгbiditу (т) of thе dispегsions was dеtегminеd spесtгomеtгiсally at }, = 540 nm,.Rйеobgt.
RhЬologiсal invеstigations of thе ball-milled or soniсatеd suspеnsions of
P\T/siliсa *.ей pе.ГoгmеJ using a Rhеotеst 2 1 (\ЕB N{LW Pгufgегatе-Wегk Меdingеn Sitz
Ftrеital' Gегmany) гotary visсomеtеr with a суlindег-суlindег systеm at thе сlеaranое betwееn
thе сylindеrs оf 0'4 mm. Thе еffесtivе visсosity (ry) was dеtегminеd at thе shеar rate B, = |312
c-t at 293 K.
Nitrogеп аdsorption, Nitrogеn (spесtгanalyzеd grade) adsoгption.dеsoгption isothегms
wеrе гесordеd at.77.35 K using a Мiсгomеritiсs ASAP 2010 (V-2.00) adsoгption analysег
Thе spесifiс suгГaсе aгеa (Sвдг) was сomputеd using standard BЕT еquation. Thе porе volumе
(Иo) was еstimatеd from adsoгption at p,,|po
^,
O 98-0.99 сonvегting thе volumе оf adsoгbеd
nitrogеn to thе volume of liquid onе
,Н NMR. Thе 'H NМR spесtгa Wегe rесordеd using a high-resolution WP-l00 SY
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(Brukeг) NЦ4R spесtгomеtеr with a bandwidth of 50 kнz. Rеlativе mеan еIтoгs wеге +l09lo fогsignal intеnsitу and +l K foг tеmpегatuге, The сalсulation tесhniquе of сhangеs in thе flгеееnегgy (ZG) of intегГaсial watег in thе aquеous suspеnsions of oxidеs using fгееzing оut of thеbulk watег was dеsсгibеd in dеtail еlsе*heгe 13-6, 10-14] ть.u'ount of fumеd siliсa in thеsuspensions was е6 w1 Yo and Сpl,? lvas сhangеd ovег thsO 3 - 5 wt, %range Thе amounts ofunfгozеn water (C"*) in thе fгozеn aquеous"suspеnsions wеге сalсu]atеd by сornpaгing thеsignal intеnsity (| fЬг thе inteгfaсial tiquiс watег and watег adsorbеd on siliсa powdег fгom thеgas phasе using the сalibгating graph I : f(С,).
T'hеrmаllу stjmulаtеrl dеpolаrisа|ioi (тsо) method. Тhe tablеts (diamеtеr 30 mm,thiсknеss -l mm) with fгozеn aquеous suspеnsioл of fumеd siliсa oг Р\?lsio2 wеге polaгizеdby thе еleсtгostatiс fiеld with intеnsitу F - 2xl0J - 5х to'it^
^t
iij* .n"n сoolеd to 100 Kwith thе fiе]d still appliеd and геhеatеd without thе fiеld using thе linеaг hеating гatе p of 0 05}7s Тhе сuггеnt еvolving duе to samplе dеpolaгisation i' ,.Joia.J Ll an еtесtromеtеr havingthе^10_'5-i0_,Aгangе'RеIativе'.un..,,o.,foгmеasurеdТSDсuггеnt
arеa=xto/o'6r=t2K foг tеmpегature, 6д = t5% for thе tеmpегatuге сhange гatе' Thе TSD spеоtra paгamеtегshavе bееn сalсulatеd in aссoгdanсе with thе equation dеsсгibing dеpеndеnсе of thе ТSDсuггеnt on tеmpегatuге
I.:sa"TPoехp(-ЕtkT-ц1сt(ЕB1*(fехpрЕ,,kT)-T"2eхp(ElkT)))
(l)whеге s is thе suгfaсе arеa of thе еlесtrodе', p i' tйe fгozеn pЪtu,l*iion, t is thе aсtivationеnегgy of dеpolarisation, тo : I/щ is a pге-ехponеntial faсtoг, and To is initial tеmpегatuге
[5,1 s]
Сomputiпg, Thе adsoгption frее еnегgy distгibution was сalсulatеd with thе Langmuiгеquation
ЬГr)-
l,+bС (2)
L
whеге 6 =,-T , oc
:,thе Gibbs fiее enегgу .цE. duе to adsoгption, R is the gas сonstanl'having rеgaгd to latеral intеraсtions (z) bеtйn PVP assumin g z : 2RI'(this z value is сlosе toZG at monolayег сovеragе), as a kегnеl in thе ovегall adsiгption еquation in thе foгm ofFгеdholm intеgгal еquation ofthе first kind
o(T, p) ='|o,q, p',).f (х)dх (3)
wheгef(х) is thе unknown distnbution п,,n.tionЪгa givеn paramеtег х. To сalсula tе thef(х)funсtion, thе геgularization mеthod сan bе usеd' as soiutionЪiЕ; i;l is wеllknown ill.posеdpгoblеm duе to a strong influеnсе of noisе сomponеnts on eхpегimental data, whiсh do notallow onе to еffесtivеlу utilizе еxaсt inveгsion formulas or itегativе algoгithms' Мonolayегсovегagе еstimatеd with Еq (2) сoггesponds to 1 : Сpl,/Сsioz = 0'18.0. l9. To сomputе thеaсtivation dеpolaгisation еnегgу distгibuiion/@o/ on th; ьu'l' Ъг TSD сuгrеnt mеasuгеmеnts,Еq (1) was usеd as a kеmеl of Еq. (з)
"Thе
rеgulaгizatiоn pгoсеduгe was also usеd toсalсulate thе porе sizе -distгibutions f(R) foг iowdеrs p.;; fгom dгiеd aquеoussuspеnsions of siliсa, P\?/siliсa and piotеiг,/siliсa utilizing й. Ы"йr adsoгрtion isothегmequation dеsсгibеd in dеtails еlsеwhеге [9]
Results and Disсussion
At pH<4 5, adsoгption of allthе studiеd drugs onto oхides is lеss than З0 % of thеir
Пl
щllц,
E
Dr-
h:-
]шlr
li i
p
31з
^60I
Е.^Е 4J
s
I
2345678
рп
5
Fig. 1. Adsoгption of (a) Proргanolol hуdroсhloгidе, (b) Еthmosinе, and (с) Vегapamil (in
pегсеnt оf thе initial сonсеntгation) onto siliсa, SAзr, and STzo at thе сonсеntration of oxidеs
of 1 wt% and drugs of 0.001 tu{ (d) Adsoгption of Vеrapamil onto siliсa in aqueous
suspеnsion stiпеd duгing a wееk (staг-like sуmbols) and 48 h (opеn сусlеs) and at 0.1 МNaCl
(гhomb-like sуmbols) and miхеd adsoгption of Vеraрamil (A) and Е{SA (r); (е) adsoцption (in
Lrg pег m2 of thе suгГaсе aгеa) of Prоpгanоlol hydroсh1oгide (A), Еthmosine (Е), and
Vегaparrul (V) onto thе diffеrеnt oхidе suгГaсеs at 0'00l i1 of drug and 1 wt% of oхidе.
initial сonсеntration' Howеvег, adsoгption inсгеasеs with inсrеasing рЕI (Fig 1) duе to thе
basiс pгоpегtiеs of thе drugs (attaсhmеnt oГ protons to N atoms as thеsе drugs aгe usеd as
Е
Е
;Е
+Asq
,,g v€o.
+!r1сж]
.,Ф. vм1
+ж?
314
l
егapamil (in
)r of охidеs
rn aqueous
! l МNaCl
lsoгption (in
:е (Е), and
:ridе.
. duе to thе
згe usеd as
dissolub]е hydгoсhloridеs) and aсidiс prоpегtiеs of siliсa (=SioН grоups) oг binalу oхidеs(=Sio(H)М=). With inсгеasing pH abovе lЕPsioz (ъ2 2)' a magnifiсation of the nеgativе сhargеof thе siliсa suгfaсe ocсuгs and attгaсtivе intеraсtion ъ,ith positivеlу сhargеd drugs inсгеasеs.Foг thе alumina (foг puге.alumina IЕPl9 8) and titania (IЕP1;92*i; phasеs in Ьinary oxidеs)?sio2, whiсh possеss aсidiс pгopепiеs (howеvег, thе IЕPу5,o,i, to*". than IЕP5;62 [l]), thесhargе distгibution is non-unifoгm and siгongly diffегs noй-on" fог siliсa with сhanging pHНoweveг, zеta potential oг еlесtгophoгеtiс mobiiity of SТ and s,A ,n aquеous suspеnsiоnsdеpеnds slightlу on thе naturе and ihе сonсеntration оf thе sесond охidе phasе and thеу aгесIosе to that foг fumеd siliсa Il'4] Тhеrеfоге, thе сhaгaсtегistiс' ;iь;";;";-;;;'.;Ъь,dеpend on thе pгopегtiеs of siliсa and thе intегfaсе ,".. ,i,""gly than оf thе sесоnd Хсomponеnt' Duе to thе сhangеs in thе intегfaсе of )(/Sioz foг diffeгJnt Х, significant vaгiationsin thе adsorption of drugs onto SА, ST, and siliсa suгfaсеs arе obsеrvеd. Foг еxamplе, SA сanbеtteг adsoгb drugs than SТ (Fig l ). this сan bе ехplainеd from thе highег aсidiс propепiеs оfBгsnstеd aсid sitеs (B.sitеs) of siliсa/alumina (A]b1н)Si) and laгgeг S valuе in сompaгisоnwith siliса/titania [4,8,12] Еthmosinе dоеs nоt adsoгb piaсtiсallу:onto thе 5Т26 suгfaсе aтpH<4 5 whеn thе titania рhasе in ST has a pоsitivе сhaгjе нo"",u",., at thе samе pH va1uеs,its adsoгption onto siliсa.suгГaсе рossеssing nеgаtivе suгfaсе сhaгgе is aррrохirna tеIу 2О Yo anddеpеnds slightlv on alkalizing sоlutiоп 1гig rБ; Еthmosinе ua,o".ption onto thе SАзt suгГaсеdepеnds on a pH nеaг linеarlу. Thе diffегеiсе in adsorptio"
"t.
P;;;;"olоl hydroсhloгidе ontсl
1/_Sio, is smallеr (Fig 1a)' but at pH>5, adsoгption onto ST is lеss than оntо SA and siliсa. AtoH<5. thе сonсеntration of Veгаpaгnil adsoгЁеd onto SA:r
''
ni*;;r. than that in thе otlrеrсasеs.
. If thе adsoгption is сalсuiatеd in g pег m2 of thе охidе suгГaсе aгеa a maхimal value isobsеrvеd foг Veгapamil adsoгbеd onto sт,o (having a small ,5), hоwеvег, thе value is сlosе toits adsoгption onto SAзl (Fig lе) Drug adsoгption 1in у'вpЬ, m2 of thе oхidе suгfaсе aгеa,1onto thе siliсa suгfaсе is гelativеly low (Fig. lе). Cоnsequейty, uсso.ptivе ability and еffiсiеnсуof fumеd oxidеs in aquеous suspеnsion геlatеd to uс,oфiion oi
'r.,.
studiеd substitutеdaгomаtiс drugs dеpеnd not only on thе oxidе natuге {e,g., avai|ability of Brоnstеd oг Lеwisaсid sitеs, elс.) but also their speсifiс suгfaсе aгеa (pгimary paгtiсlе sizе distгibution).
Upon joint adsoгption of HSA and Vегapamil ontoihе siliсa suгfaсе from sоIution, thеinfluеnсе of pгotеin is геlativеly small (Fig 1d)' howeveг, thе соnсеntгation of thе drug in thisехрепmеnt was lowег thu:
.up91 its adsoгption withоut HSA and thе сuгvе
'lop."'iightiyinсгеasеs' This сan bе еxplained bу adsoгpiion of thе drug onto bоth thе siliсa suгГaсе anoalbumin, as HSA is the main tгanspoпation pгotеin in bloЪd and drug transрoгtation in thеhuman bodу сan oссuг with its paпiсipation дdditionully' maхima of adsoгption of Vеrapamiland HSА are not сoinсidеnt (Fig. ld) as the рFI(IЕP) valuеs of thеsе сompounds diffег(typiсally, adsorption of сhaгgеd paгtiсlеs oг molеЬulеs strongiy in.i"u,., at a pн nеar IЕP duеto disappеaгanсе of thе еleсtгostatiс геpulsivе intеraсtion). iш'o, u* pн>IЕРsioz, protеin сaneffесtivеly intеraсt with the oхidе suгГaсЬ through amino gгoups witь attaсьed pгotons. А]so, -Coo_ gгoups of HAS tuгnеd into thе bulk solution .un ,йonjty inteгaсt with pгotons attaсhedto amino 8rouрs of thе drug, whiоh is dissolvеd poorly in thйolесulaг statе and usеd only ashydгoсhloгidеs. Consеquеntly, adsoгption of pгotonitеd dгugs oг pгoteins onto thе oхidеsuгfaсе dеpеnds mainlу on thе diffегеnсе bеtwееn a given pй uuluе of thе suspеnsion andpн(iЕP) of thеsе сompounds (Fig. 1).
Тhе сompaгison studiеs of BSA adsoгption on thе suгfaсе of fumеd siliоa, titania,alumina and miхеd oхidеs show thе Ыghest adsoгption iin .g рег ',l
- -""i.j
alumina./titaniа/siliсa (Fig. 2) having thе smallest-Sв1= 3s *1ug, гo.tii., a maхimal adsoгptionvaluе (in mg/g) inсгеasеs with dесrеasing S, Foг diffегеnt SA'"suсh an еflесt is not markеd as
з15
thе diffегеnсе in thе S valuе is smallеr than that for diffеrеnt ST and adsoгption onto siliсa or
SA is сlosе to that for STg having thе sресifiс suгfaсе aгеa сlosе to Ssll. Howevеr, thе
еffiсiеnсy of adsoгption of BSA 1in и) fгom sоlution is thе grеatеst foг siliсa possеssing the
laгgеst S valuе from thе studiеd Ьxidеs (Fig. 2). Thе diffегеnсеs in.the adsoгptive abilitу (in
both % and mg m-.) of ST and SA at a low сonсеntration (Сх) of thе sесond phasе is small.
Thisеffесtisсausеdьу.,"rutш.rуunifoгmdistгibutionofthеminorphasе(smallС,)inthеsiliсa
matгix and the similaпtу-ь tь. p,op.пies of )oSioz and siliсa' е'g.,in ( as a funсtion oГpН
[ 1,4]
Fig. 2. Adsorption of BSA in (a) mg pег
m2*of thе suгfaсе оr (b) pег g of diffеrent
oхidеs as a funсtion of pH.
Adsoгption of BSA оnto oхidеs at
lolv сonсеntiations oГ oхidеs (C*) in
susреnsion inсrеasеs еxponеntialiy with
dесrеasing Сo, and slightlу dеpеnds on the
natuге of oxidеs (Fig з) Howеvег,
геduсtion in Сo* is aссompanied bу a
stгong dесгеasе in thе еffiсiеnсу of protеin
adsoг"ption (Fig 3b) Thе diffегеnсе in thе
adsoфtion in pегсent of thе initial
сonсеnt.ation of BSA is largеr than that.in
.g p., g оf oхidе (Fig з) еspeсiallу foг
йЪi.'u!p.n'ion of fumеd siliсa agеd
duгing two months.
Protеin adsoгption on oxidеs in thе
untгеatеd suspеnsions (Tablеs 1 and .2)
dесreasеs in сompaгisоn with adsoгption
of BSA or HSA aftег геlativеly long
stirгing of thе dispеrsion (Fig. 2). Тhis
diffеrйсе сan bе сausеd bу a lowеr
a
20
Эg 15
э< 10
7
?
h
Е
1400
12о0
1000
E00
600
400
aссеssiblе suгГaсе aгеa of oxidеs in untгеatеd suspеnsions fог biopolуmеrs as large oхidе
agglomеratеs (>10 рm) Ьuin in suspеnsion.in сonirast to thе fumеd oxidе suspеnsions after
'ong
MC{ stiпing o. uri,u,onl. trеatЬеnt tr] RеiЦvе stabilitу of а'gglomеratеs сan bе linkеd
with inсгеasing uppu,.n,.l."й "r'ь.
po*a.,' (Tablе 1) that сoгrеlatе with a dесгеasе in
pгotеin adsorption. Th;.,;;t'; diffеrеniе in adsoiption of g.еlatin and еgg albumin is lowег
ihan thе геlative аir.,.n.. in thеir molесulaг wеighi qч. t: o*l:."1.11thеir forms, as еgg
albuminisaglobularprotеinbutgеlatinisеllipsoidalwithalaтgеaxlalratlo'
A maximal adsoгption of thе last protеrns is obsеn,еd ioг SAzз whiсh has the maximai
numbег of =Si-o-A.l= anЪ =Si.o(H).АJ= bгidgеs (l.e', Bгonstеd aсid sites, rvhiсh сan stronglу
inteгaсt with bаsiс amino gгoups of protеinj at t1е i"':{1::. Puт,e fumеd titania gives a
rеlativеly grеat valuе "iuаJ*p'Ь"
of gеlatin that is in agгееmеnt with thе largе adsoгption oГ
BSA bу this oхidе (Fig 2) and thе гatio in adsoгption oi gеlatin and еgg albumin by ST9 anс
STш (Tablе 1) is сlosЁ to that upon adsoгptlonЪгBSA. Consеquеntlу, adsoгрtivе abilitу оf
fumеd oxidеs dеpеnds on thе oxidе trеatmеnt but thе геlationship bеtwееn protеin adsorption
bу oхidеs ofthе diffегеi;;;ъй i' kеpt and dеpеnds on thе сonсеntгation ofthе sесond oхidе
. SAll+sтc. sт20
9 sтз6
316
lto siliсa or
)wеvег, thе
ssеssing thе
е ability (in
lsе is smail.
in thе siliсa
;lion of pH
]a) mg pег
rГ diffеrеnt
:.. oxidеs at
эs (С*) in
:.:ially with
:::ds on thе
Нowеvег,
::.rеd by a
: ' оf protеin
з:.:^се in thе
:hе initial
' ::an that in
:.:есiallу foг
.,Liсa aged
:'':dеs in the
:s 1 and 2)
-: зdsoгption
:::.' еly long
'; 2). This
: . a lowеr
i :гge oxide
:o:,sions aftеr
:,.i bе linked
r :эсгеasе in
.--:r is lowеr
:: -ns, as egg
s ::.з maximal
! ::.n stгongly
к':::a givеs a
r:.эгption of
г :." STя and
r . ebility of
r :Csorption
l ;.:.'.nd oxidе
ъl*sо. l
l -..-.rcАsiо
||..-sд' l ]i-+ s]э
|
-
I
phasе and сhaгaсtегizе thе nаturе of suгfaсе sitеs (mainly B.sitеs)
30ф
юоо
,1ф0-
O
Е
q
!-с
'-
fд
t\r\
t\
\
Fig. 3. BSA adsoгptiоn i;l (a) mg
^pег
g of drffеr-еnt oюdеs and in (b) pегсеnt of thе
lfl;1":a.."tгation
in thе solutiоn u' Jd.,n.tlоn oГ thе .on..n,*,lon оf охidе in aquеous
Tаblе l
Platеau Adsогptiоn of Еgg А]bumin and Gеlatin ontо Individual and N{iхеd oхidеs
n оГ oхidеsoхidе аppu..ntDffi---ъ.'"'й-
-
lU -]Э 1] 15 zС
Фjde Ccnоentratioп (vit%) .Jх:dе Concеnirаtion (!1,t%)
,)m-sio2
А]zoз
Tio2
SАч
q Д.^
SТэ
SТzo
090
058
0.72
1.0
\.94
084
],С)
m, --2
r.20
056
1.86
t67
z'zч
1з5
r 81
i8
t47
86
28
э/'
t)
270
87
JD
i80
3з0
t80
72
3б0
84
93
300
380
29О
130
Aл inсгеasе in S еnhanсеs thе adsогption (in mpg) оf both pгоtеins (Tablе 2);howеvеr, adsогptiоn in rг,g/m2 gоеs dоъ,n *iii s аu. ,o ,.сйil"lг с)н (silanols aге thе rnainadsorptiоn sitеs) and a pоssiblе inсгеasе in thе stabilitу oг,,"й.,,.1йtеraсting rvith ргоtеins)
;,:l.*Т]}:g
pгimary paгtiсlе sizе Pгоtеin adsогptiЬn .i,.. .,uiiь Еor, rndеpеrrdеntlу on thе
P\? having pоlaг bonds N-C=o in thе basiс sidе grоL.rps еnhanсеs ,H(IЕP) of thеtsoеlесtгiс point (IЕP) nеaгlу linеагlу r,l,ith Сilr, u',]':l] as th; ( рotеntlal is rеduсеd .wtth
Сpуpat a сonstant Сs,o,. in j\{СA.siliсazP\? susреnsion (Tabiе 3) Тh; iu;g;.;"'bег of polaг N-с=obonds in P\{P molесulеs is геsponsibtе foi iгrеv^еrsibtе uаso.ptioo oЕpvp on siliсa suгfaсе duеtо hydгogеn, Polar, and,^е|есtгЬstatic bonding, P\? molесui;,.;;;Ь; hold pгotons oг mеtalсations, whosе intегaсtion with thе siliсa i.,.гu..*'".gu'iu.l,;;;; at pH > рH(iЕP5;92)еnhanсеs thе adsoгption еnегgу dеtегminеd mainly by thе hуdгоgеn bonds Adсiitionallv.
з17
intегaсtionbеtwееnoandNatomsfromP\Цand=SioHgroupsсanсausebuildupofthе
suгfaсе сhargе dеnsitуЪ",u'.",^,.i.i.,, *t'i.i^а.p.no1 9i3,*аnd
thе оonсеntration of
еlеctгolуtеs in thе sotut"й]i; il ;;";g "d;;';;;; "г
pw molесulеs on siliсa partiсlеs
геsults in inсгеasе rn pН(IЕP) and dесrеasе t;;;;; to shiеlding of thе oxidе suгГaсе by
polynег mоlесulеs.
f;!l;i.r,u,", oшut*
'"'tu'
uno Ou"uu oo'o'ot'o'-o'tnou*'n uno ot'ut'n
- N"--т-- Сoн Albumtn -2 :'j:] -o m-2
\121g u*oi* : .n g-l Цg m' m,q-B
, mF!Ц
1 102 ТТ-zoо l 96 170 l 'o /
2 |48 з8 3 1.62
3 19.I ;ъ 210 ]
o6 295 | 49
4 |92 ; ; 1:у i i: 12o, i,'i
г .aб з'2 JlU l lr
) t t'L
6 293 ;; 280 0 95 з2o
'
o:
7 300 2'g з46 115
8 275 30 315 114
9 з08 3.0 1?9 l 03 307 1.0
10 30s Jo з50 114 3s0 12з
1 l 36s 2,6 380 1 03 25О 0.68
1,2 384 i в 450 1 17 42o 1.09
13 390 1, в 410 1.05 41o 1.21
14 410 i, ц 430 l 05 450 l i0
15 цtt 1ц звo o gz 2oo
-=},a8-
Тablе 3 qllenРnqiоns of Purе P\T' Fumеd Siliсa qnd P\T/SjЩa
Paramеtегs of PD
Samplе Lrrе '-''!i .,]t, ЦmJ.rrrPrv
цt9/o vlo/o m\-- . |l':- u',, >5О
P\T ' - 1(1 srl 07tP\T ' . 1<1 521 078 0.440
sio, (A-300): : -i;; \ ot 016 ozss
sio2 (A-3oo)
iii',aЁi li i 'з: :'li 'у,\^1, Z;З\Ъ
:3,#s: ъТ i 1: | 2,,: 8.ii 3
з43
sio2/P\rP" ,i i i^: t'r',
3 il 3 13!
.t t.Nole'
.МcA.susг11sionЪ}:T]:Т#i.i]i':;:;;;;i,iri.u
bеforе (5 min) thе mеasurеmеnts
i"?Ь'r-,'
ipllp uddi'ion to thе samе МCA.suspеt
(non-soniсated samрlеs)
МultimodalPSDisobsеrvеdforsiliсadispегsions(Figs.-4and,5)havingagglomегatеs
at dpcs: 1-i0 рm and ,.".*r tуpеs of .****;;:;:;;;;ъ'; thе.lion's shaгe of thе paпiсlеs
has thе ,12g = 60 n* (гie,. s .1а ьp
)^1у".in"
ol'"ry paпiсlеs^of A-300 havе thе sizе
mainly ovег 5- 15 n* ,ungЪ, i
"
. Dan (avеrag. аi"'.tЁ, гo. tье first pеak) сorгеsponds to small
of thе
.ion of
iftiсlеs
aсе by
'oniсatеd
jгеmеnts
Omегatеs
paгtiсlеs
,thе sizе
; to small
:Ё-,:..Ё1x.Ж"Ыlizatiоn
of lоl'l amоunts ot Рi,Р сhаЛgеs; tirе РSL)s (i:igs 4-,7), anсJ thс. sizе
m o 1 е с i i е s d l ; ;',,;;;;:::i1' lx {,|,,i :,!,,, ;,,/;;;. ,*.т Ё, J i*. i:, .i *т;# hi(PD = 0 005) is obsеп,еd at (]pr,,"= 5 wt.. у"'(,,,=-t) and n.uit1,'onnaispегsе distribution isobsегv'еd at lowег P\? amounts (Figs 6с-and аol o. " ii"",l"s ,"t,n С."r,, (Fig 8a) is maхimelat Сpу,r:0.24 w% (у = o о+в,), йi.ь i, lowеr than 1,, *"''.o fbг statistiсal monolayегсovегagе (], = c, ]8-0 19) or (|р;'p for P\? stronglу bound (т = о {,r9) ti: т.hс :.il;::r surfЪое.
}"'lJliJ"x}]E :;ж:r
foг alL paгiсlеs iл; a*.."u,., и,i,сj,.tТablе 3) duе tо геduсtiоn
Тhе suspеnsion,tuгbiditу (г) (Fig 8a, сuгv'е 1)' as rvell aS D^in, гisеs duе to P\?aggrеgatiоn with small oxidе aggгеg-atеs r,.',ith simuttanеous dесomposition оf laгgеagg]omегatеs with inсгеasinE Сprc ю o i ll,t чъ; howеvег, ;;;;;;", slightly rvith subsеouеntеnhanсеmеnt of Сprp to 12'n1.o^ Thе sеdimеnt volumе Гoгmеd-duгing lt) jдy5 dерenjs оnСдlр (Fig 8b. сurvе,]
T" PVPisi()2'u,p.n,ion is stablе u, c,,i=..0 l2-0 24 уч1 Yoanсj dоеsnot pгaсtiсаllу ехfoliatе Гог 10 deys' дt iье lаst СЪlэ,'uiй-u,u,imal visсоsity is obsег..еd(Fig 8b' сun.е 2) duе то suspеnstоn struсIuгi.
disruptесt on й"oiog;.al inuеstigai;; ;t'J,';:.:il:xfiH":i-'T,1.i"J;[;Т::Hт;;
inсгеasing shеaг гatе 1B,) givеs dеi':ation of thе сuп,еs ao' tьo,. fо. Nе,r.tоn liqшid t'lоli, lfthе гatе of rеaгrangеtnent of d..o*рo,.Jьonс, is lеss thаn th;;;fi;",, dесompоsitiоn that thеvtsсosity tаpегs оfI (duгing thе гhеolоgiсal mеasuгеmеnts) -until еqualizatiоn of thе гatеs О|diгесt and rеvегSе ргoсеssеs This еquilibгiu.,.o.y.., quiсkl}, for рuге siliса susрепsrоn, whiсhshows its геlativеly low thiсkешng, *ьi.ь .u.к.аrу in"i.asеs a"" io uссi.iun of Р\?" It shоuldbе notеd that thе гhеopеху еffесt is obsеrvеd at С,,,,, o u *i" ij o
')
ь. agеd suspепsiоnсопеsponding to an еnhanсеmеnt of thе .;isсositу duгing thе
'еusu.е.еnts duе to a gгеatеггatе of bоnd rеarran*:i:ll than,dесompositioг.Ii li fь.
"l,"o,i,, o"p.nаеnсе on Cpyp a|maхimal !,= 1З12 с_lсhangеs duе to aging oгlье.,u,p.n,lon- гi,.,u*p.nsion agеd for 3months, ry has a highеr maхim um at Сеr.р -Ъ 2 rvt 9,o and lowег valuеs at Сpyp ) o'4 wt % (Fi.8b' сuгvе 2) than that foг lгеshlу ;;;р.*; suspеnsiоn (гig. вb, сuгve l), as dispеrsionstruсtuгization is a long proсеss, whiсh ian геsult in ult..utйni i.,ii.,t*.tuге of both dеnsеadsoгbеd laуег and intеr-paгtiсlеs bonds r,r'ith Ся;,г
Саlсulations of сhangеs in thе frее еnегg]v'duе to Р\T adsoгрtiоn (Гigs l0а аnd l0b)and thе сoпеsponding dегir'ativе (Fig 9a' аu'ьйrin.;
"'iщ'щ,"i"tуltt'l]
\l.l$S' tuа аnd l0b.
whеrе K is thе еquilibгium сonstan,,^,o;i,;]",i.. ,,,.on* uс,o,o,,on of P\? on ,iti.!a)i,obsеrvеd at thе еquilibгium соnсеntration r'|7у7, <,С) 1 wtok 1he f(*G) pеaks bеtw"ееп *9kJ/mol and -1',7 kJlmol (Fig 9с) aге linkеd *iiь ,u.ь an intегaсtion ai tow prry сonсеntгatioпIt shоu]d bе notеd that obsеrvеd sсattеr
'"
,1I':ч j: i::,;ji;ё;iFig. 9с) соmputеd usingP\,? adsorption isothегms гесoгdеd undег thе samе соriditioпs ii сuе to сomplехity ofP\?/si02 suspеnsions as fuпrеd siliсa possеsses fou.-stеp,ui,. й.i",ur hiегaгсhу [1], whiсhсhangеs on P\? adsorptiоn duе to dесЬmpo,i,ion оf laгgе ugglu;;;;;;, and геaгrangemеnt ofag$гegatеs' The АG value is сlоsе to zeГo at С,r" - 0 75 uлYo(Fig 9) andf(АG) peaks at АG-> 0 сoгrеsponding to wеaklу adsoгbеd P\? (grеat r:,,,7,'*.n|,"(, rs in agrееmеnt withгhеologiсal invеstigations showing d;пr,nution ;n йw i,u..*..;""..*;.n ,n. siliсa suгfaсе atovегall соnсеntгation Сpуp> 0'24 wtok
319
t
Ф!
{
пi
0
ь
Diameter (nm)
Diameter (nm)
1ф
Diameter (nm)
Diameter (nm)
Diаmeter (nm)
Diameter (nm)
di
ФP
Eо
ф^
t
!
Fig. 4. Partiсle sizе distгiЬution in (a) thе МCA (foг 5 h) suspеnsion oГ siliсa; (b) fгеshly
pгJpaгеd siliсa suspеnsion soniсatеd for 9 h; (с-f) MCA (foг 5 h) suspеnsion of PVP/siliсa at
Сpw=О'l3 (с),0.25 (d), O.3s (е) and 0.5 уtt,Yo; PVP addition (Сеw=25 (ф and 5 wt' %
(h)) to МСA.suspension of siliсa preйously tгеatеd for 5 h; Сsioz= 5 wt.o/o (a.h) (ZеtaРlus
appaгatus).
T
lil
f,f;
ffi
fifi
o.=359 nm
T
Diamеtеr (пm)
з20
trL э) fтeshly
f,].?/siliсa at
! i:: 5 wt. %
tF. 'ZеtаPlus
Ь-з0
20-
'a
}фо
10
5
0
20
- 10
0,
1oo 2oo 300
d (nm)
t6o-_.-Зio
I
I
a
d.с5 (nm )
Fig. 5. Paпiсlе sizе distгibutions in rеsресt to tho light sсattrгing (solid lines), partiсle volumе (dashсdlinеs) and paпiсlе numbеr (dot.dаshеd linеs) foг thе щuеоus suspеnsions of fumеd siliса A.300sontсatеd for 5 mrn nt С5,q2 ='0 25 (a) and l (b, с' d) wt.% and pH = d sz t"l, 7.0з (b)' 8.8 (с), and 5.3(d) (Zеиsizеr 3000 aрpaгafus).
.J
}а.l;lт'*.ж'i:::'",',..,::l?:J:,:,:]:.jyg:|:T*:'" чth a в1v9n d'iamеter) forМCA-susрпsioпs
!f:';:;j,Jl'};l?'l*:Т:\iIl*.":":y]-.:l,PviБЮ;;;;:.;;;;l,;Ёffiffi;]ffЁъ:;
ъ!}?-У',*,,:Pl':::.":.:il,,i. 2* -:'?:уY:tP!ш'йc.й (.)ё-:.j.'Ь?").,Ёff#;lЪ"#Сpп= 0,3 wt'% (histogram 2у, G) СP].P= o +в *t."z"(й ;;-;й'6'';,i.{I,;,i<ii <iiЁ,HЁffi}"ii
d.с5 (nm )
ti
iril"! r'
I-!iL- . i
з2|
d
Ф
100
dPсs (nm)
Fig. 7. Paпiсlе sizе distгibutions in rеspесt to thе light sсatteгing (solid lines), partiсlе volumе
(dashеd lines) and paгt;ь numbеr (dot.dashеd tlnБ9 ьг the aquеоus suspеnsions of fumеd
siliсa A.300/P\rP soniсatеd foг 5 min at Csioz :o.25 (a-d) and 1 (е,f) wt% and Cpvp/Csioz =
Ы.i,q; pн valuеs aге shown in thе lеgеnds (Zetasizeт 3O00 apparatus).
з22
a 1E
t4
200
1ф
0
t0
Fig. 8. (a) Tuгbidity of PvP/sio2
suspеnsion vегsus Cлил at сonstant Сs,oz =
6 wt,уo (сuгvе 1) and D,,n (avегagе
diamеtег foг thе first pеak in thе paгtiсlе
sizе distгibution) as a funсtion of Сpw
(сuгvе 2). Еffeсtivе visсosity of P\P/Sioz
suspеnsion vегsus (b) Сpvp at сonstant C5,6l2
: 6 wlуo foг fтеsh (сuгvе 1) and agеd foг 3
months (сuгvе 2) dispеrsions; and sediment
volumе as a funсtion of Сpw foг suspеnsion
agеd during l0 days (сuгve 3); and (c) Сsioэ
at C pуp/С 5,92 = О '1, .
ao
,U
loo Х
€
0800
o.200 04
с,",. (wt'%)
.AG
Fig. 9. (a) АG on PVP adsoгption on siliсa
(Cs,o, : 6 wt%) сalсulatеd with Еq (a)
and сoпеsponding deгivative d(АG)/dСrvr
(solid symbols); (b) АG on P\T adsoгption
on siliсa (Csloz = 5 wt'%) сalсulatеd with
Еq (4); and (с) lG distгibution сomputеd
with Eq. (2) as a kегnеl of Еq (3) with thе
rеgulaгization pгoсеduге.
--rlra-(l I
ь il
-li
Е
J .0ф
&-
]lr
lЕ
е volume
эf fumеd
.; \-sio2 -
з2з
Changеs in avегage сhaгgеs of oxidе paгtiсlrs upon agglomеration with PVP molесulеs сan
lеad to rеduсtion in tьe
-zеta
potentiai in сompaison *itь thе purе aquеous .sчч9nsio1s .of
fumеd siliсa (Fig 10) aй to..ыu'gemеnt of ihе shеaг laуег thicknеss and shielding of thе
suгГaсе by P\{Р molесules' Thе zеtфotеntial of thе miхturе is a nonlinеar funсtion of pH and
itsсhangеsatpH>бarеmoгесompliсatеdthanthosеarеatpH<5(Fig10)AtpHэl0,thе
}po,.niiut oгЪwisiliоa сhangеs in oppositе diгесtion in сomparison with that of puге siliсa'
This еffеоt сan bе ехplainеd йom trapping сations (H- or mеtal сations) bу PvP molесu]еs
bound to thе siliсa suгfacе that сausjs rеduсtion in thе avегagе сhargе of thеsе complех
agglomеrates сonsеqйtlу, adsогption 9f |vP on thе siliсa suгfaсе at pH >
'H(IЕP)
doеs
not inhibit strong intеraсtion of Pф with dissolvеd сations' Loсalization of сations bеtwееn
the sidе гings of Pvp сan pгomotе a tightеr adsoгption of P\,? onto thе siliсa suгГaсе having
inсrеasеd nigativе сhaгgе densitу with pH > pH(IЕP).
Е
б
с
Ф
ФN
'10
0
Fig. 10. Zеta potеntial at diffегеnt Сs,o:
and С,,o valuеs for thе bail-milled
susoеnsions of PVPisiliсa. Тhе samplе
witЬ thе astегisk at Сs,oэ= 3 wt' o/o was
pтерarеd bу dilution of 6. wt. %
suspеnsion (ZеtaPlus appaгatus).
Changеs in thе statе of thе
intегГaсе of P\?/siliсa сan сoгrеlatе
with altегations in thе adsorbеd watеr
laуеr. Fоr ехample, a strong intеraсtion
bеtwееn реptidеs and siliсa paгtiсlеs
сausеs a геduсtion in thе amounts of
unfгozеn intегГaсial watеr in сompaгison
with a puге pгotеin solution or a pure
siliсa suspеnsion [5].
TwospесifiсгеgionsinthеgгaphofАG:Go-Gvеrsusthегеlativеamountsofthе
unfгozеn inteгfaсial *.tЕi icil [1a]"сan bе found in Fig 11 for thе-puге si1iсa, PVP/siliсa, and
ball-millеd P\rPlsiliоa ,u,pЪn'lЬn, ih" fi.,t сorresponds to a signifiсant dесlinе in thе amount
of unfгozen wateг in a rеlativеlу narтow rangе of АG at T nеaг 27з K, and foг anothег геgion,
the amount of unfгozеn watеr goеs down slightlу, but АG сhangеs moге strongly. The
intегГaоial watеf, rеsponsiblе for-thе first геgioi,
"ol.,еsponds
to a rеlativеlу thiсk laуег of
watег wеaklу bound to thе suгfaсе and pепurЬеd duе to thе long-гangе сompoIlеnts. of
intеrmolесulaг intегaсtion (main]у еiеctrostatiс and polaг). Aлothеr wаtег (stгonglу bound to
thе suгfaсе) геsponsiblе гo, tье sесond геgion in the АG gгaph is linkеd to a tЫn laуer adjaсепt
to the suгfaсе. Its сharaсteгistiсs arе influеnсеd bу shoп-rangr сomponents of the intегaоtion
(suсh as polar, Lifshitz-van dег Waals, and еlесtrostatiс) [i] bеtwееn the suгГaсе and adsorbatе
molесulеs. Thе amount of еaсh tуpе of watег and
.maximal
valuеs of thе сorrеsponding
сhangеs in thе frее enегgy of thе intЪгfaсial watег iayеrs (z1G, and АG*) сan bе еstimatеd by
ехtгapolation of thе сoйsponding dереndеnсiеs to thе х and y aхеs on thе graph АG(Сф
[la]' Thе /G: (ovегall rеduсtion й thе Gibbs frее suгfaсе еnеrgу), АG,, АG- Ca,, and C,щ
valuеs arе givеn in Тablе 4 foг thе ball-millеd susреnsion of pure siliсa and PVP/siliсa. Thе
intеraсtion bеtwееn P\rP and siliсa suгfaсе геduсes АG and C,р but С,м inсrеаsеs.
-} 1и% *Фo}о 1*.* Fr'P
+ з^i96 *@+0 }tr6 Pr'Р
+ }* Aзoo}0 э^t95 F/P
Ф 6Ч^96Aз.0
\l\\
t\
- о - silс.
-...- siIc..0.3 wl*Pвs
+silсr.1и% PvP
+ sitс!}5 и% PvР
]ulrs сan
rsions of
lg of thе
f pH and
= l0, thе
lге siliсa.
lolесulеs
сomplех
ЕP) doеs
i bеtwееn
се having
э:еnt Сs,oэ
эall-miiled
:-з samplе
'i: %o waS
: rд't. %
.i l
:i of thе
' ;orтеlatе
:: еJ watеr
-:':еraсtion
а эaгtiсlеs
г,]unts of
:'- зpaгison
: ]г a purе
Fig. 11. Тhе freе еnеrgy сhangеs oГ thе
intегfaсial watег as a funс1iоn оf thе
amounts оf unfгozеn watеr iпr-q) pсr g оf
oхidе foг month-stoгеd bаl|-miilеd
suspеnsions of рuге siliсa (С5,p2 = 6 *t 9,o)'
puге solution of P\T (Сpу,p= 1 и 96), bail-
millеd suspеnsion of P\?/siliсa (sttlragе
pегiod of 1 month) at, Сs,oэ: б r* C,с апd
Сprr = 0 3 wt oь' and siliсa su-cpеrrst.:г. аt
Сs,oz: 6 wt ok' Сpт,p: I оr 5 lv1 'iъ сl| гliгр
0 5о0 1000 1500
C"* (mз/s)
This геsult is in agгееmеnt with геdrrсriоn in
thе zeta potеntial of tlrе Р1;P,'si1rса
suspеnsiоn (Fig. l 1) Ал еnhanсеmеnt in С,м сan bе duе to thе nonuniГoгm еlесtгоstatiс fiеld
in a rеlativеly thiсk intегfaсial layег, Thе amount of wеaНу bОund watеr in this laуег is laгgеr
than that aгound thе рuге siliсa paпiсlеs (Tablе 4) as wеll as thе thiсknеss of thе iпtегГaсial
layег pегtuгbеd by P\? + dissolvеd ions and siliсa paпiсlеs in сompaгison with that fог thе
initial siliсa suspеnsion, as polymег molеculеs sеt a signifiсant poгtion (all P\rР mrэlесulеs arе
bound to thе siliсa suгfaсе) in this layег, howеvег, thе sum C,,s** С,д is thе sarnе' lt shorrld
bе noted that еvеn a vеry long.pегiod stoгagе of thе ball-millеd suspеnsiоn of siliсa has e lvеak
еffесt on АG |5J' and thе diffегenсe bеtwееn thе сoгrеspond\ng АG2 valuеs is onlr l] mjimz
that is in agrееmеnt with a high adsoгptivе abiliti, of fumеd siliсa in thе agеd ba]j.пrillеd
suspеnsions tеstеd using protеin adsoгption' 0 3 wt' % of P\? imрaсts thе stгonglv bоund
intегfaсial watег сlosе to 1 wt. 0% of puгe PVP (Tablе 4, c"f* and АG"), Thе wеakly bоilnd
watеr is pегturbеd by 0 3 wt % of PVP in thе physiologiсal buffеr solution wеakеr than liу l
wt % of puге PVP; howеvег, сhangеs in thе Gibbs frеe еnеrgY oithis laуеr (АG",) are simiiаr
An inсrеasе in Cеут to 5 wt' % lеads to gгowth of thе thiсknеss of thе unfrozеn watег iaYег
(Fig l1), C"r'+ C"r. and АGz (Tablе a) Notiсе that the sum lG, + АG. (Тablе 4) is in
agгееmеnt with thе rеsults basеd on thе P\? adsогption date (Fig. 10). Тhesе сhangеs in thе
intегfaсial watег (i.e., ЕDL) suggеst an incrеasе in thе bonding intегaсtion bеtwееn paпiсlеs
and polymег molесulеs in thе PVP/siliсa systеm that givеs еnhanсеmеnt in thеiг agglomеration
(floссulation) and сoпеsponds to thе laгgе valuеs of D-,, and D"; (Figs 4-8)
Tablе 4
IntегГaсial Watеr Paгamеtеrs foг Siliсa and P\?/Siliсa Suspеnsions (Сs,o:: 6 wt 0/o)
Systеm АG, АG' C"f* C,fn АGz
kJ/mol kJ/mol mgC mp/g niJ,'m2
sior(I) з,2
1,0
э
Е-
о.
P\?
l.:.:s of thе
] s:iiсa, and
::.з amount
1- .:r rеgion,
:::.gly. Thе
i.с:. laуеr of
:::lеnts of
:r lound to
г-.:: adjaсеnt
Ё .:.1еraсtion
;с зcsorbatе
:г:sponding
:::.rated by
с- -зG(Сф
,. znd Cup
J .:.iсa. Thе
c
'Sio2(I)+O.з вt.% P\? 2,5
SiOz(II)
1 wt % Р\|Р
SiOz(II)+t wt % PVP 3.0
700 700 253
500 900 186
730 680 279
300
52О 1б00 22О
1400 403
30
l6
t.J
1.0
1Аt'т
09
SiO,(II)+S wt % P\? 3.0 1.0 1 100
Notе Sвдrд,3O0 and 190 m, g_'foг sio,(I) and Siou(II), rеspесtivеly .In phуsiologiсal buffеr
-11-")
ш.
20
Aсtivation Еnergy (kJ/mol)
30 40
Fig. 12. Distnbutions of thе aсtivatiоn еnerg1, of TSD for puге watег (сuгvе 1), watег (7
й.иj uа,o,bed on siliсa in thе gas phasе (2); P\P/Sioz at Сs,oэ = з wt3k and Сpw = 0.12
,м'"l,,сil,Sio2suspеnsionatСs,Jz =..Iwtjk(a);P\rPlSio2xtС5pz=,7wl.o/oandCpw=0.28
wt.% (5), Sio2 suspеnsion at Сs,o: = |4 wtoА (6), P\ry/Sioz a| Сs,oz = 14 wt'o/o aod Сpvp =
0.56 wt Й (7); and puге PVP solution at Сplе = 0 56 wt % (8).
TSD studу shows сhangеs in thе statе of Watег and pоlymеr molесulеs with incrеasing
Сpvp and С5;92 (Fig. rzl sirй paпiсlеs in thе сonсеntratеd aqueous suspеnsion (Сs'o.z-=,7
wt'% (сuгve 4) or 14 *t.и 1"u*. 6)) disrupt thе hydrogеn bond nеtwoгk in a signifiсant
;;;.;, as thе Ьuk frее watет (/(tl pеak at 44 kJ/moi in сun'е 1) is praсtiсallу absеnt at suсh
aсonсentгationofsiliсatr,sl i"tЁeЪasеofP\T/SiozsuspеnsionatthesamеCslo:(сuгvеs5
uJ т) o, at lowег G,,, (сu*е 3), thе amounts of thе bЦlk watег are largеr than that foт puгe
siliсa suspеnsions; howеvеr, the displaсеmеnt of this peak towards- lowег eneгgу with G,oэ is
obsегvеd (i'e,, avегagе numbеr of hуdrogеn bonds pег a molесulе tеnds to diminish).
Consеquеntly, shiеlding oithе siliсa ''.ьф.ьv
polуmеr molесulеs results in appеaгanсе of
nеaгly frее bulk watеr di,uppеu.ing in thе pфz.sio2 suspеnsiоns at largе Сsioz = 14 wt'oЬ
6й 7) oг in purе siliсa ,u,p.n,ion (сuгvеs 4 and 6) oг puгe P\rP solution at Cpvp :О.56
wt.% (сuгvе 8) Additionallу' inсrеasе in thе сonсеntгation of siliсa in P\rPlSioz dispегsion
results in appеaгanсе of watiг molеculеs with a low numbег olhуdгogеn bonds pег a molесulе
оoггеspondin g to tЬe f@) pеak at low .Е, = 1 0- 1 5 kJ/mol, whiсh shifts towaгds lowеr t, with
inсгеasing Сs,oz + Сpl'p (Fig. |2)
326
Thus, аt low Cpr,p, polymег molесulеs adsoгb stгongly (largе сhangеs in the Gbbs fгee
еnегgy) and thе numbеr оf fгеe pугrolidonе gгoups сan bе rеlativelу low; i.e., adsoгbеd PVP
layег is геlatively dеnsе and intегaсtion bеtwееn watег molесulеs and oxidе paпiсlеs oг P\?
molесulеs disturbs a minoг poгtion of thе watег. At grеat Сpw, a signifiсant poгtion of РVP
molесulеs has fгее tails (at I *,О.2, thе relativе numbеr of frее C=o groups in P\T adsоrbеd
on siiiсa fгom solution and thеn dгiеd at room tеmpегatuгe is appгoхimatеly 2/3, aссoгding to
IR speсtгa), whiсh do not intеract with thе siliсa suгГaсе but еffесtivеly intегaсt with watеr
molесulеs, and a laгge poгtion of watег is disturbеd' Thегеforе' the АG(Сф gгaph shifts
towards Largеr С,p (Fig. 1l) andf(Е) shifts towaгds lowеr Е" (Fig. 12) duе to геduсtion in thе
numbег of hуdгogеn bonds pег a molесulе. Thеsе fеatuгеs оf thе adsorbеd PVP layег and
геduсtion of thе numbег of P\T molесules intегaсting with sеvеral oхidе paпiсlr swarтns
simultanеously сausе diminution in thе visсosity with Сpr.р> О.З wt.% (Fig s).
Powdегs prеpaгеd by soft drying oГthе aquеous suspеnsions of fumеd siliсa йth drugs
or polymеrs (е g
' P\T) сan bе of intегеst as possiblе mеdiсinеs; thегеГoге, suсh matегials wеге
studiеd using thе adsoгption and PCS mеthods. Thе struсtuгal сhaгaсteгistiсs of thе solid
геsidual of the suspension of fumеd siliсa diffег siрifiсantly fгom thosе of the pгistinе siliса
powdег (Tablе 5, Fig 1з); foг instanсе, thе spесifiс suгfaсе area Sввr dесгеasеs, but thе porе
volumе (И,) inсгеasеs and a maгkеd pеak of thе poге sizе distгibution/(R,/ apрears at Дo > i0
nm, Thef(R) distгibutions wегe сomрutеd on thе basis of the nitrogеn adsoгption-dеsorption
isotheгms using a сomputation teсhniquе dеsсгibеd in dеtails еlsewhеге [9] Noticе that thе
diffегenсe in thе pгistinе powdег paгamеters results in thе diffеrеnсе in thosе foг thе solid
геsidual of thе dnеd suspеnsions (Тable 5) and one сan assumе that smallег pгimary paгtiсlеs
(laгgeг Sввт) in dгiеd powdеrs from the suspеnsions from moге dеnsеlу paгkеd struсturеs.
Addition of 5 wt.o/o of PVP (in rеspесt to С5;q2 сoггеspoпding to op1p < 0'5) геsults in inсгеasе
in V, but dесrеasе in .Sвдт and the f(R,) реak slightly shifts toward laгgeг Л,. Addition of 10
wt.% of PVP (at opvp сlosе to i) lеads to stгong геduсtion in Vo and a small diminution in SЪgг
that is in agгееmеnt with thе displaсеmеnt of the main f@,) pеak toward smallеr \. In the
сasе оf thе albumin oг gеlatin adsoгbеd on siliсa (Tablе 5)' сhangеs in thе struсtural
сhaгaсteгistiоs arе smallег thaп thosе for PVP/siliсa (Fig. 13).
Тablе 5
Struсtural Paгameteгs of Pгistinе Powdегs and Dгiеd Suspеnsions of Fumеd Siliсa,
Sili"a/PVP, Sili"uДgg Albu.in .
Powdеr
. . watег (7
Z .-':p = О'12
с '- ?|P = 0.28
! : 1od Сpvp =
l..::^ inсrеasing
i::. lLsro2 - /
г. : signifiсant
i:sеnt at suсh
--..
.,. (сuгvеs 5
; ::.at foг puге
i. .r ith Csioz is
:: diminish).
::Dеaraпсе of
":: = 14 v'rto/o
.... Сpe,r :О.56
! Э1 dispеrsion
:е: a molесule
s .]wег Е, with
"A-300
oA-3oo
oA-зOO/P\?
oA-3oo,ryw
.A-з00*
oA-3oo*
ЬA-зO0*/Atbumin
oA-3oo*/Albumin
ьA-з0O*/A]bumin
ЬA-зo0*/Gelatin
ьA.300*/Gеlatin
342 0 5б6
182 0.612
170 О '92з
1'57 0.з83
3Zl U.OIJ
2'7 5 1.147
175 0.903
Cх (wt %) Sв^вт Vo
-(Х=PvP' А]bumin) m"/P. сm"lg
)
1n
-tt.,
2з0
27.6
21"1,
15'l 0.868
l3 8 0.'724
14з 0..745
123 0.701
Note. "Pгistinе powdег, dгiеd powdегs fгom solid геsidual of thе suspеnsions.
З27
Тhе PSDs foг P\T/siliсa suspеnsions (Figs. 4-11 can bе multi. or monomodal
dеpеnding on thе сomponеnt сonсеntгations and pH Howеvег, small aggrеgatеs givе thе main
сontгibution for all thе samplеs duе to dесomposition of agglomегatеs and large aggrеgatеs of
pгimary siliсa paпiсlеs undЁ, aсtion of polymеr molесulеs, This геsult is in agrееmеnt йth the
1фs ii,t'iьutЬns for P\?/siliсa powdirs (Fig. l3) showing dесomposition of siliсa struсturеs
,'.й"'lьr.
for foгmation of largе mеsopoгеs at Ro> 15 nm Small aggгеgates givе thе main
сontгibution not only to thе PSDs in rеspесt to thе рaгtiсlе numbеr (PsD09) but also to thе
paгtiсlе volumе (P SD(V))
х.
0.14
0.12
010
0.08
nnA
0.04
0.02
0.00 20 30
Pore Radius (nm)
Fig. 13. Poге sizе distпbutions for pristinе fumеd siliсa A-300 and powdегs pгеpaгеd by drying
;;.;"' suspеnsions of siliсa, P\4p7siliсa, еgg albumir/siliсa, and gеlatirr/siliсa.
ThеpеaksofthеPSDSinrеsресttothelightsсattегing(PsD(i))sЫfttowaгdlargеr
dpсs in сomparison wltt1 PSD(N) and PSD(V). In ihе сasе of еgg albumirr/siliсa (suspеnded-
dгied.suspеndеd), thе гSos dеiеnd on thе albumin сonсеntration (C.ь) (Fig. 14) and thе
distributions bесomе.or. "onlд.х
with C"rь, At a maхimal Сulь valuе, a laгgе pеak of PSD(V)
appеaгs at dpg]> l рm iгig rц.l сопеsponding to agglomеratеs with thе main сontгibution of
pгotеin molесulеs as гsф) has a low int^еnsltу*in this геgion (сlеarlу, thе sсatteгing сapabilitу
of protеin molесulеs is lowЬг than that of siliсa paгtiсlе swaгms)
'Additionally,
small particles
at dpgg> 30 nm .un .o,,.,ponc to both albumin molесulеs and srliсa рaгtiсlеs as PSD(I) has
low intеnsitу at dpg'5 bеtwееn 30 and l00 nm.
*- A.300(dnеd susp.)
.Q..- +28% Aibumin
- - +31% Gеlatin
..-.'A-300*
.-.- A.з00(dnеd susp.)
^-
+5% PVP
+10% PYP
#ы-.t...-J\t
з28
lonomodal
е thе main
]гegatеs of
nt with thе
' struсturеs
е thе main
also to thе
:зJ by drying
:: 'r ard laгger
t Suspеndеd-
.:) 3nd thе
i.: эf PSD(V)
с::nbution of
::.; сapaЬility
г:.зll partiсlеs
', PSD(I) has
30
.:
э
б ZU
'1 0
0
1
З0
zэ
'r 2o
э
о 15
1o
25
I -r/:'. ."-t'--\
10с0
20
' 15g
10
5
0
100
Fig. 14. Paпiсle sizе distributions in rеsресt to thе light sсattегing (soiid linеs), paгtiсlе volumе
(dashеd linеs) and paгtiсlе numbеr (dot.dashеd tinеЪ; foг thе aluеous suspеnsions of fumеd
siliсa A-300/egg albumin (susреndеd-dгiеd-suspеndеd) at Cs,oz = оzs wt.Yo and Cor/Csioz:
0.112 (a),0 23 (b) and 0 276 (c)
400 500
d (n m )
з29
For all thе protеirr/siliсa samplеs, thе PSD(V) pеaks liе to- thе lеft fгom PSD(I) that
сoггеsponds to thе uuыйьiti'y of lu,g. agglomeratеs of protеin molесulеs with smallеr
сontribution of siliсa paгtiсlеs. Thеrеforе onе сan assumе that intегaсtion of еgg albumin with
siliсa suгfaсе is wеakег than intгa-molесulaг intеraсtions in pгotеin moiесulеs (i.е., globular
struсtuге of pгotеins doеs not dесomposе) in сontrast to P\rP molеculеs, whiсh inteгaсt with
thе siliсa suгfaсеs ,.,ong., than onЁ moleсule with anothеr. This featurе of protеin.siliсa
intеraсtions геsults in u *Ъuк influenсе of pгotеin molесulеs on thе porе foгmation on drying of
thе pгoteirr/siliсa suspеnsions (Fig. 13), but oppositе геsults is obsегved for P\?/siliсa.
Сonсlusion
lr{aximal adsoгption (in mg/m2) of BSA was obsегvеd in tгеatеd aquеous suspеnsion of
alumina/titaniа/siliсa. гol. g.tutin" oг еgg albumin, adsorption is maхimal for non.treatеd
suspеnsion SAzз, A.*i'il adsoгрtion oгBSA (in my'g) and drugs (in peгсent of thе initial
сonсеntration) fгom soluтiсln was found foг siliсa po''.Ъ'ing thе highеst S valuе among a1l thе
studiеd oхidеs. Нor,l,еveг, adsoгption of drugs in рg pег m2 of thе oxidе suгГaсе arеa is a
maхimal foг STzo' наsolption оf vегapamil_and НЬA fгom mixеd solution onto thе siliсa
suгfaсе shows a wеak influеnсе of thе protеin on thе drug adsorption but thе сoпеsponding
slopе inсrеasеs' Foг vеry small сonсеntration ofoxidеs in aquеous suspеnsion, BSA adsoгption
(inmg/g)inсгеasеsе*pon.ntiarty.withdесгеasеinoхidесonсеntration,howеvег,thatis
aссompaniеd ьу o".,"u!йg ii. .m.i."су of alburnin adsoгptiоn (in pег сеnt of thе initial
сonсеntration) from thе solution.
r of fumеd siliсa and its
Addition оf poly(йnуl ругrоlidonе) to thе aquеous suspеnsloг
mесhanoсhemiсal aсt'vaiiоn o,- sonicutiоn еnhanсе thе еffесtivе diamеtег of the paгtiсlеs
dеpеndingonpH.AtpF{сlоsеtoр}'!ry:)'laгgеpaпiсlеsobsегvеdсanbеfoгmеdduеto
agglomегation of siliсa paгtiсlеs witь pr,p .olJсuiеs oг oхidе paгtiсles thеmsеlvеs, as thе
геpulsivе еlесtгostetiс forсеs bеt*,ееn thеm arе wеak in сompaгison with thе attгaсtivе polar
and Lifshitz-van се. waats forсеs' By and largе PVP irrеvеrsible adsorЬеd on thе siliсa suгfaсе
at thе сonсеntrations less than 10 7" of thе amount of oxidе сausеs nonlinеar сhangеs in thе
сharaсtеristiсs of thе PVP/fumеd siliсa suspеnsions (vсrяs Слил), suсh as йsсosity, effeсtivе
diamеtег of paпiсlеs, .i..t,opьo,.tiс mobilitу, diеlесtгiс. paгamеtетs, intегfaсial watеr layеr
statе, еtc. Intra.mоlесuiu, ini.,u.tions in gloЪulaг protеin mo|9сч]9s aгe strongег than that
bеtwееn thеsе molесulеs and thе siliсa suгfaсеs in сontrast to P\?/siliсa.
Aсknowlеdgеmеnt
This rйеarсh Was supportеd by NATO (gгant
Committее for Sсiеntifiс Rеsеaгсh and N,Iinistry of
(grant No' 2МJзОз-99),
_ 2O0O. _ У. 1'61,N 3. _ P. 229-24з.
3. Aquеous Suspеnsions of Highly Dispеrsе
V.I.Zarko. V'V,Turov, R Lеboda, Е Chibowski,
Rеfеrеnсеs
l. Aquеous Suspеnsrons of Fumеd oхidеs: Paпiсlе Sizе Distгibution and Zеta Potеntial /v.М.
сunкo, v.I Zaiko, R Lеboda, Е. Chibowskill Аdу, Colloid IntегГaсе Sсi., in prеss'
2'IntеraсtionоfProteinsandSubstitutеdAromatiсDrugswithНighlуDispегsеoxi.dе.1in
AquеousSuspеnsionsllV.М.Gun'ko,N.N.Иasova,L.P.Golovkova'N.G.Stukalina,
I.I'Gегashсhеnko, V.I'Zarko, V.A.Tisсhеnko, Е.V.Gonсharuk, A.A.Chuiko // Colloid. Suгf. A.
No ЕSТ.CLG 976s90), thе Polish Statе
Hish Еduсation and Sсiеnсе of Ukгainе
Siliсa and Gегmania/Siliсa / V.М.Gun'ko,
V.V'Gun,ko // J. Colloid lntегГaсe Sсi. -
330
::.. РsD(I) that
5 with smallег
i; albumin with
l: li е., globulaг
,::. interaсt with
:: эгotеin-siliсa
:'- - :n drying of
-,-:-
-:) l.
l.:.]П].
1998 _У 205 -Р.106-120.
4. Thе Еffесt of Sесond Phasе Distпbution in Dispегsе VSiliсa (Х= A]2oз, Tio2, and Gеoz)on its Suгfaсе Pгopегtiеs-/ V.М.Gun.ko, v.rz-i.o, v,vl"'""). к.,-"ьoаu, Е'Chibowski zlLangmuiг. _ |999 _ v. l5, N l8. _ p. sвЬц-sтoz.
5. Featuгеs of Aquеous Suspеnsions of Fumed Siliсa and Intегaсtion with Pгotеins /V.М.Gun'ko, V,V..Tuгov,
.У'I.Zarko,
V.VDudnik,
';.i;,.hеnko,
Е.F.Voгonin'
3 i.:Т;}""a,
S S Silсhеnko, and A.A.CЬuiko //J Colloid. rntеггaсе Sсi. _ I997. - У, 192. _
6. C\D-Titania on Fumеd Siliсa Substгatе / V.]v{'Gun,k o, У.I.Zarko, V.V.Тurov, R'Lеboda,Е.Сhibowski, L Holysz,.Е.М'Pakh]ov' Е.F.Voгonin, V.V.6udnik, yu.r.сo.niкov // J. Соlloid.IntегГaсе Sсi - 1998 _ V. 198. _ P 141-156
7. Struсtuге of Pуrogеniс Tio.z and Tio2/sio2 and Influеnсе of thе Aсtivе SuгГaсе Sitе Natuгеon Intегaсtion with Wa-tег i.V.М.Gun,io, i'?э,у:. Е сhi;;;;i,.v v.оuan;k, R,Lеbodа,V'A'Zaеts // J. Colloid. It]teгfaсе Sсi. _ ls6z - v. 188 - P' Зg-57.8' Сharaсtегizatioп of Fumеd А.lumina/Siliсa/Тitania in thе Gas pьasе anс Aquеоus Suspеnsioni vМ. Gun'ko, vI Zaтko, V.V тuiou, R. Leboda, в. ёhibowsи, Е.МPakhlоv,Е'V.Gonсhaгuk, М.Мaгсiniak, Е F Voronin, A A.Chu tko //J'Col'oid. Intегfaсе Sсi _ l999. -v 220, N2 -P Зo2-з2з.
9 Highlу Dispеrsеd ,":]9, and CD(Sio2 (Х = Alumina, Titania, Alumina/Titania) in thе Gasand Liquid Меdia / V М. Gun,ko, v.I. ia.ko' к r-еЬoаa, й. й,сiniak' W Janusz, S.Chibowski // J. Colloid Intегfaсе sсi _ 2o0O _ У.2зО _P З96-4o9l0. Сhaгaсteгization of Fumed Siliсas and thеiг Inteгaсtion with йatег and Dissоlvеd Pгoteins/ I F. Мiгonуuk, V.М.
.Gun-ko, V V Tuгov' i,1 zы,кo'к I-.ьoau,l. Skubiszеws ka-Zipba //Colloid. Suгf А. _2oo1 _ V l80' N l-2 - Ь вz.roill' Aquеous suspеnsions.of highlу dispегse siliсa/polу(vinyl pyггolidon e) /l У,М. Gun,ko, V.I.Zarko, Е' V. Gonсharuk, V. v..Turov, Е i vo.onin, s v. pul.ьouсhishin, Е. М' Pakhlov,N' V. Guzеnko, R Lеboda, Е. Chibow'кi, д
_д
Chuiko // Colloid Suгf .\ submitted.12. Aсtivе Site Natuге of Pyrogеniс Аluminа/Siliсa and wu....Bound to Suгfaсеs /V.М.Gun,ko, V.V.Tuгov, У.I2arko, Е'F.Voronin, vд'iisсhеnko, V.V.Dudnik,Е'М'Pakhlov, A.A.Chuiko //Langmuir. -,|ggi._ v. 13, N 6. _ P. 152g-L544.l3. Diеlесtгiс Pгopегtiеs and Dфmiс Simulation of Watег Bound to тitaniыSiliсa Suгfaсеs /
],Y'?.":,i";у::;ri,у,V Tuгov, Е'F. Voronin, V.A.Тisсhеnt.o, д д.сьuiкo zz r-angmui.'
14. Gun'ko V'М., Tuгov V.V Struсtuге of Hydгogеn Bonds and lH NМR Spесtгa of Wateг atthе Inteгfaсе of oxidеs //Langmuir' _ 1999,jv. ts, N 19 _ P 6405-б4t5l5. Tisсhеnko V.A., Gun,ko VМ. Watег Еleсtrеt Rеlaхation at Dispегsеd Si1iсa Suгfaсe /iColloids Suгf A.- 1995 _ v. 101, N 2/3. _ P 287-294
-.-!.^
... lс.
i ^: *
|
| id | oai:ojs.pkp.sfu.ca:article-70 |
| institution | Surface |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2025-07-22T19:30:03Z |
| publishDate | 2001 |
| publisher | Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine |
| record_format | ojs |
| resource_txt_mv | surfacezbircomua/7b/b16f39c6bfe7e8ea4f91a6078816dc7b.pdf |
| spelling | oai:ojs.pkp.sfu.ca:article-702018-11-27T09:42:39Z Interaction of bioactive compounds with highly disperse oxides in aqueous suspension Interaction of bioactive compounds with highly disperse oxides in aqueous suspension Interaction of bioactive compounds with highly disperse oxides in aqueous suspension Gun'ko, V. M. Zarko, V. I. Turov, V. V. Vlasova, N. V. Voronin, E. F. Gerashchenko, I. I. Golovkova, L. P. Goncharuk, E. V. Leboda, R. Chibowski, S. Chibowski, E. Chuiko, A. A. Interaction of polymers (albumin, gelatin, polyvinylpyrrolidone) and some drugs with fumed silica in aqueous dispersions was studied using adsorption, NMR, photon correlation spectroscopy, electrophoresis and thermally stimulated depolarization methods. The impact of polymers on the structural and adsorptive properties of suspended-dried fumed silica was explored using nitrogen adsorption method with the regularization procedure. Interaction of polymers (albumin, gelatin, polyvinylpyrrolidone) and some drugs with fumed silica in aqueous dispersions was studied using adsorption, NMR, photon correlation spectroscopy, electrophoresis and thermally stimulated depolarization methods. The impact of polymers on the structural and adsorptive properties of suspended-dried fumed silica was explored using nitrogen adsorption method with the regularization procedure. Interaction of polymers (albumin, gelatin, polyvinylpyrrolidone) and some drugs with fumed silica in aqueous dispersions was studied using adsorption, NMR, photon correlation spectroscopy, electrophoresis and thermally stimulated depolarization methods. The impact of polymers on the structural and adsorptive properties of suspended-dried fumed silica was explored using nitrogen adsorption method with the regularization procedure. Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2001-06-10 Article Article application/pdf https://surfacezbir.com.ua/index.php/surface/article/view/70 Surface; No. 4-6 (2001): Chemistry, Physics and Technology of Surface; 310-331 Поверхность; № 4-6 (2001): Химия, физика и технология поверхности; 310-331 Поверхня; № 4-6 (2001): Хімія, фізика та технологія поверхні; 310-331 3154-8091 3154-8083 en https://surfacezbir.com.ua/index.php/surface/article/view/70/69 Авторське право (c) 2001 V.M. Gun'ko, V.I. Zarko, V.V. Turov, N.N. Vlasova, E.F. Voronin, I.I. Gerashchenko, L.P. Golovkova, E.V. Goncharuk, R. Leboda, S.Chibowski, E. Chibowski, A A. Chuiko |
| spellingShingle | Gun'ko, V. M. Zarko, V. I. Turov, V. V. Vlasova, N. V. Voronin, E. F. Gerashchenko, I. I. Golovkova, L. P. Goncharuk, E. V. Leboda, R. Chibowski, S. Chibowski, E. Chuiko, A. A. Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_alt | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_full | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_fullStr | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_full_unstemmed | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_short | Interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| title_sort | interaction of bioactive compounds with highly disperse oxides in aqueous suspension |
| url | https://surfacezbir.com.ua/index.php/surface/article/view/70 |
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