Colloids and Surfaces最新文献

Polymerization in non-aqueous lyotropic liquid crystals: Influence of the unsaturation site 非水溶性液晶中的聚合:不饱和位点的影响

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80005-Z

Stig E. Friberg , Bing Yu , Ahsan U. Ahmed , Gregory A. Campbell

引用次数: 9

On the stability of concentrates. Non-aqueous dispersions 精矿稳定性研究。非水乳液

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80008-4

E. Ruckenstein

引用次数: 12

Micelle dissociation kinetics study by dynamic surface tension of micellar solutions 胶束解离动力学的动态表面张力研究

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80006-2

V.B. Fainerman, A.V. Makievski

{"title":"Micelle dissociation kinetics study by dynamic surface tension of micellar solutions","authors":"V.B. Fainerman, A.V. Makievski","doi":"10.1016/0166-6622(93)80006-2","DOIUrl":"10.1016/0166-6622(93)80006-2","url":null,"abstract":"<div>The dynamic surface of sodium tetradecylsulphate and sodium bexadecylsulphate solutions in water and also in Triton X-100 solutions was measured by the maximum bubble-pressure method, using modern computerized instrumentation, for a wide range of surface lifetimes (from 0.001 to 10 s), temperatures (from 30 to 80°C) and surfactant concentrations (from 1 to 200 CMC). On the basis of a previously suggested adsorption kinetics theory for micellar solutions of ionogenic surfactants (V.B. Fainerman, Colloids Surfaces, 62 (1992) 333) a method was developed for the calculation of the micellar dissociation rate constant k. For the surfactants studied, k increases with increasing concentration. Moreover, for ionic surfactants the dependence of k on concentration (C) becomes more striking for C> (10–30) CMC. This can be explained by a micelle shape transition and by a strengthening of the intermolecular repulsion in micelles. In solutions of the ionic surfactants the constant k increasing with increasing temperature, whereas in Triton X-100 solutions a temperature dependence is absent. This phenomenon is associated with the different nature of the molecular interactions for ionogenic and non-ionogenic surfactants in micelles. The k values, obtained from results of dynamic surface tension measurements, are in satisfactory agreement with the results of a study of the relaxation of micellar solutions published previously.</div>","PeriodicalId":10488,"journal":{"name":"Colloids and Surfaces","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0166-6622(93)80006-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77473609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Contact angle kinetics of human albumin solutions at solid surfaces 人白蛋白溶液在固体表面的接触角动力学

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80001-V

R. Miller , S. Treppo , A. Voigt , W. Zingg , A.W. Neumann

引用次数: 33

Open circuit potential measurements with Ti/TiO2 electrodes Ti/TiO2电极开路电位测量

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80003-X

Marcelo J. Avena, Osvaldo R. Cámara, Carlos P. De Pauli

{"title":"Open circuit potential measurements with Ti/TiO2 electrodes","authors":"Marcelo J. Avena, Osvaldo R. Cámara, Carlos P. De Pauli","doi":"10.1016/0166-6622(93)80003-X","DOIUrl":"10.1016/0166-6622(93)80003-X","url":null,"abstract":"<div>The open circuit potential (OCP) vs pH response of Ti/TiO2 electrodes prepared by thermal and electrochemical oxidation of metallic titanium was measured in KNO3 aqueous solutions in order to establish whether the slopes of the OCP-pH curves can be used as a measure of the variation of surface potential (ψo) of TiO2 with the pH of the aqueous solution. For comparison purposes, ψo—pH slopes were also evaluated from surface charge-pH data obtained by acid-base potentiometric titrations of TiO2 dispersions.Ti/TiO2 electrodes showed a linear OCP-pH response in the range of ph 5–10 with slopes of −0.039 ± 0.005 V ph−1. The OCP-pH dependence of Ti/TiO2 electrodes was lower than that predicted thermodynamically. According to the triple-layer model, used to describe the oxide/aqueous solution interface, the OCP-pH slopes obtained for Ti/TiO2 electrodes cannot be identified with the variation of ψo with the pH. Calculations with this model indicated that neither the single nor the double extrapolation methods used to evaluate the intrinsic ionization constant of oxide surface sites render realistic values of these parameters for the TiO2 surface.The analysis of surface charge—pH data and the use of the triple-layer model to predict experimental values indicated that the ψo—pH slopes of TiO2 surfaces must be greater (in absolute magnitude) than 0.041 V pH−1.</div>","PeriodicalId":10488,"journal":{"name":"Colloids and Surfaces","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0166-6622(93)80003-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79238073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Science and technology of carbon black 炭黑科技

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80011-4

引用次数: 0

The adsorption of phosphamidon on the surface of antimony(V) phosphate: A thermodynamic study 磷酸锑(V)表面吸附磷酰胺的热力学研究

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80007-3

K.G. Varshney, A.A. Khan, Upma Gupta, S.M. Maheshwari

引用次数: 6

Relaxation of adsorption layers at solution/air interfaces using axisymmetric drop-shape analysis 利用轴对称液滴形状分析溶液/空气界面吸附层的松弛

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80002-W

R. Miller , R. Sedev , K.-H. Schano , C. Ng , A.W. Neumann

引用次数: 67

Zeolite '93 沸石93

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80010-D

引用次数: 0

Zwitterionic surfactant solutions 1. A light scattering investigation 两性离子表面活性剂溶液光散射研究

Colloids and Surfaces Pub Date : 1993-01-18 DOI: 10.1016/0166-6622(93)80009-5

Alok Bhatia , Syed Qutubuddin

{"title":"Zwitterionic surfactant solutions 1. A light scattering investigation","authors":"Alok Bhatia , Syed Qutubuddin","doi":"10.1016/0166-6622(93)80009-5","DOIUrl":"10.1016/0166-6622(93)80009-5","url":null,"abstract":"<div>Dynamic and static light scattering studies are reported on a series of alkyl dimethyl betaines CmDMB (m = 12, 16, 18) in aqueous solutions as functions of surfactant concentration, salt concentration and temperature. The characteristics of the micelles change dramatically as the alkyl chain length is increased from 12 to 18. In the case or C18DMB, large micelles form at very low surfactant concentrations (about 0.2 wt%) and grow rapidly to become entangled at slightly higher concentrations (about 1 wt%). Upon addition of salt, C18DMB micelles become very large and semiflexible. At 40.3°C the persistence lengths of C18DMB micelles in 0.01 and 0.1 M NaCl aqueous solutions are approximately 1400 ± 200 Å and 1600 ± 250 Å, respectively. The persistence length of C18DMB micelles in 0.1 M NaCl solution at 51.5°C is 1650 ± 250 Å. The dynamic light scattering data are consistent with estimated persistence lengths. Quantitative agreement is obtained with the theory developed by Fujime and co-workers (S. Fujime and M. Maruyama, Macromolecules, 6 (1973) 237; T. Maeda and S. Fujime, Macromolecules, 14 (1981) 809) for semiflexible, rodlike particles. Micelles of C16DMB in water are very small compared to C18DMB. The micelles are polydisperse and the size increases with increasing surfactant concentration. In 1.0 M NaCl aqueous solutions, the C16DMB micelles are larger than in pure water and become semiflexible. After accounting for polydispersity, the persistence length is calculated to be roughly 600 ± 100 Å at 25°C. Therefore, micelles of C16DMB are less stiff than those of C18DMB. In contrast to C18CMB and C16DMB systems, C12DMB micelles remain small and spherical over a wide range of surfactant concentration, in agreement with previous studies.</div>","PeriodicalId":10488,"journal":{"name":"Colloids and Surfaces","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0166-6622(93)80009-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78415705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12