Polymer Gels and Networks最新文献

Polymer Gels: Synthesis and Characterization 聚合物凝胶:合成与表征

Polymer Gels and Networks Pub Date : 2018-01-01 DOI: 10.1007/978-981-10-6083-0

引用次数: 5

Sclerox-chitosan co-gels: Effects of charge density on swelling of gels in ionic aqueous solution and in poor solvents, and on the rehydration of dried gels 硬壳聚糖-壳聚糖共凝胶:电荷密度对凝胶在离子水溶液和不良溶剂中的溶胀以及对干燥凝胶再水化的影响

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(98)00037-9

Bo Guo , Arnljot Elgsaeter , Bjørn E. Christensen , Bjørn T. Stokke

{"title":"Sclerox-chitosan co-gels: Effects of charge density on swelling of gels in ionic aqueous solution and in poor solvents, and on the rehydration of dried gels","authors":"Bo Guo , Arnljot Elgsaeter , Bjørn E. Christensen , Bjørn T. Stokke","doi":"10.1016/S0966-7822(98)00037-9","DOIUrl":"10.1016/S0966-7822(98)00037-9","url":null,"abstract":"<div>The equilibrium volumes of swollen carboxylated scleroglucan (sclerox) gels crosslinked with chitosan, were studied as function of salt concentration, salt type, pH and solvent composition. The degrees of carboxylation of sclerox were Dcar=0.05–0.3. The ratio between the equilibrium volume of the swollen gel and the reference volume, V/V0 showed a dependence on NaCl concentration in aqueous solvents for the various Dcar that conformed well to the theory for swelling of polyelectrolyte networks. Also the dependence of V/V0 on the valence of the simple electrolyte predicted by this theory was reproduced experimentally. In aqueous iso-propanol solutions without added electrolyte, the sclerox–chitosan gels collapsed for volume fractions of propanol, Wp, larger than 0.64. Increasing the imbalance ratio of the polyampholyte sclerox – chitosan co-gels by increasing the fraction of chitosan showed that V/V0 decreased for pH values where electrostatic attractions between NH+3 of chitosan and COO- were effective. The swelling behavior of rehydrated, dried gels showed qualitatively the same response to various solvent conditions as the never dried gels, but there were minor quantitative differences. This study shows that sclerox–chitosan co-gels possessing polyelectrolyte or polyampholyte nature can be made by varying the molecular parameters of the gels, and thereby control how these gels respond to various aqueous salt solutions.</div>","PeriodicalId":20331,"journal":{"name":"Polymer Gels and Networks","volume":"6 6","pages":"Pages 471-492"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0966-7822(98)00037-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76894818","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: 21

The effect of uniaxial deformation on swollen gels 单轴变形对膨胀凝胶的影响

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(98)00036-7

Suresh L. Shenoy

引用次数: 4

Kinetics of the shape change of magnetic field sensitive polymer gels 磁场敏感聚合物凝胶形状变化动力学研究

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(98)00033-1

Miklós Zrı́nyi , Dénes Szabó , Hanns-Georg Kilian

引用次数: 68

A study of the gelation mechanism of poly(vinyl alcohol) in aqueous solution by high-resolution solid-state 13C NMR spectroscopy 高分辨率固态13C核磁共振光谱法研究了聚乙烯醇在水溶液中的凝胶机理

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(98)00031-8

Masatoshi Kobayashi , Masahito Kanekiyo , Isao Ando , Shigetoshi Amiya

引用次数: 11

Rheological study of the chitosan/glutaraldehyde chemical gel system 壳聚糖/戊二醛化学凝胶体系流变学研究

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(98)00032-X

W. Argüelles-Monal , F.M. Goycoolea , C. Peniche , I. Higuera-Ciapara

{"title":"Rheological study of the chitosan/glutaraldehyde chemical gel system","authors":"W. Argüelles-Monal , F.M. Goycoolea , C. Peniche , I. Higuera-Ciapara","doi":"10.1016/S0966-7822(98)00032-X","DOIUrl":"10.1016/S0966-7822(98)00032-X","url":null,"abstract":"<div>Chitosan dissolved in 0.1moll-1 acetic acid shows an apparent yield stress at very low frequencies, probably due to a structuring process yielding gel-like response. It reflects complex relaxation mechanisms once chains disentangle and relax, presumably due to incipient hydrophobic contacts reinforced by the relative stiffness of the chitosan chains, which tend to slow down reptation. When chemical cross-linkages are introduced, the weak self-associated network of chitosan is gradually replaced by a permanent covalent network as the molar ratio of aldehyde/amine groups, R, is increased. At R=0.4 a glass-to-rubber-type transition is observed, while at R=0.5 the form of the mechanical spectrum suggests the co-existence of a chemically cross-linked gel ‘dissolved’ in a second entangled network formed by chitosan chains of restricted mobility. At higher cross-linking levels (R>1) a strong permanent gel is formed. The observed frequency dependence near the rheological gel point suggests several modes of relaxation processes.</div>","PeriodicalId":20331,"journal":{"name":"Polymer Gels and Networks","volume":"6 6","pages":"Pages 429-440"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0966-7822(98)00032-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77310177","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: 91

Poly(2-hydroxyethyl methacrylate-co-sulfobetaine)s hydrogels: 3. Synthesis and swelling behaviors of the [2-hydroxyethyl methacrylate-co-N,N′-dimethyl (acrylamido propyl) ammonium propane sulfonate] hydrogels 聚(2-羟乙基甲基丙烯酸酯-巯基甜菜碱)水凝胶;[2-甲基丙烯酸羟乙基-co-N,N ' -二甲基(丙烯酰胺丙基)丙烷磺酸铵]水凝胶的合成及溶胀行为

Polymer Gels and Networks Pub Date : 1998-12-01 Epub Date: 1999-05-25 DOI: 10.1016/S0966-7822(99)00002-7

Wen-Fu Lee, Chin-Fu Chen

{"title":"Poly(2-hydroxyethyl methacrylate-co-sulfobetaine)s hydrogels: 3. Synthesis and swelling behaviors of the [2-hydroxyethyl methacrylate-co-N,N′-dimethyl (acrylamido propyl) ammonium propane sulfonate] hydrogels","authors":"Wen-Fu Lee, Chin-Fu Chen","doi":"10.1016/S0966-7822(99)00002-7","DOIUrl":"10.1016/S0966-7822(99)00002-7","url":null,"abstract":"<div>A series of the 2-hydroxyethyl methacrylate/N,N′-dimethyl-(acrylamido propyl) ammonium propane sulfonate (HEMA/DMAAPS) copolymeric gels has been prepared from various molar ratios of HEMA and the zwitterionic monomer DMAAPS. The influence of the amount of zwitterionic monomer in the copolymeric gels on the swelling behaviors in water, various saline solutions, and various temperatures was investigated. Results indicated that in the equilibrium swelling ratio (Qeq), the PHEMA hydrogel exhibited a minimum Qeq at 55°C. Then, the minimum Qeq was more obvious when higher zwitterionic monomer, DMAAPS, content was added into the HEMA/DMAAPS copolymeric gels. In the saline solution, the swelling ratios of HEMA/DMAAPS copolymer gels increased rapidly with increasing concentration of the salt, and with smaller ratio of charge/radius. In dynamic swelling behaviors, the PHEMA hydrogel (DM0) and the HEMA/DMAAPS copolymeric gels with lower DMAAPS content (DM1 and DM2) exhibited overshoot phenomena. The maximum overshoot value decreases with increase in temperature.</div>","PeriodicalId":20331,"journal":{"name":"Polymer Gels and Networks","volume":"6 6","pages":"Pages 493-511"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0966-7822(99)00002-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83439154","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: 18

Two mechanisms of gel/surfactant binding 凝胶/表面活性剂结合的两种机制

Polymer Gels and Networks Pub Date : 1998-10-01 Epub Date: 1999-04-12 DOI: 10.1016/S0966-7822(98)00030-6

Olga E. Philippova, Lilia A. Chtcheglova, Natalia S. Karybiants, Alexei R. Khokhlov

{"title":"Two mechanisms of gel/surfactant binding","authors":"Olga E. Philippova, Lilia A. Chtcheglova, Natalia S. Karybiants, Alexei R. Khokhlov","doi":"10.1016/S0966-7822(98)00030-6","DOIUrl":"10.1016/S0966-7822(98)00030-6","url":null,"abstract":"<div>The interaction of poly(methacrylic acid) gel with cationic surfactant, cetylpyridinium chloride (CPC), has been studied at pH of the solution ranging from 6.0 to 2.0. It has been shown that the value of pH has a dramatic effect on the swelling behavior of the gel in the surfactant solution: at pH>2.5 the gel collapses, at lower pH the gel swells. At the same time, the total amount of CPC absorbed by the gel is only weakly dependent on the value of pH. The results were explained by the interplay of two mechanisms of binding of surfactant by the gel: electrostatic and hydrophobic. The former leads to the gel collapse, while the latter one induces the gel swelling. The contribution of each mechanism has been estimated. It has been shown that at high pH the electrostatic forces play an essential role, while with decreasing pH the gel ionization is suppressed and the hydrophobic interactions between the alkyl tails of the surfactant molecules and the gel chains become dominant. Thus, it has been demonstrated that the swelling behavior of the gel upon absorption of charged surfactant can be radically altered as a result of the changeover from electrostatic to hydrophobic mechanism of the surfactant binding.</div>","PeriodicalId":20331,"journal":{"name":"Polymer Gels and Networks","volume":"6 5","pages":"Pages 409-421"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0966-7822(98)00030-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76114361","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: 29

Physico-chemical properties and rheology of alginate gel beads formed with various divalent cations 不同二价阳离子形成的海藻酸盐凝胶珠的理化性质和流变性

Polymer Gels and Networks Pub Date : 1998-10-01 Epub Date: 1999-04-12 DOI: 10.1016/S0966-7822(98)00035-5

C Ouwerx , N Velings , M.M Mestdagh , M.A.V Axelos

引用次数: 261

Structural characteristics of oxidized scleroglucan and its network 氧化硬化葡聚糖的结构特征及其网状结构

Polymer Gels and Networks Pub Date : 1998-10-01 Epub Date: 1999-04-12 DOI: 10.1016/S0966-7822(98)00024-0

Hitoshi Maeda , Tommasina Coviello , Yoshiaki Yuguchi , Hiroshi Urakawa , Giuseppe Rambone , Franco Alhaique , Kanji Kajiwara

引用次数: 7