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首页> 外文期刊>Journal of Applied Polymer Science >STUDY OF CRYOSTRUCTURATION OF POLYMER SYSTEMS .12. POLY(VINYL ALCOHOL) CRYOGELS - INFLUENCE OF LOW-MOLECULAR ELECTROLYTES
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STUDY OF CRYOSTRUCTURATION OF POLYMER SYSTEMS .12. POLY(VINYL ALCOHOL) CRYOGELS - INFLUENCE OF LOW-MOLECULAR ELECTROLYTES

机译：聚合物体系的低温结构研究.12。聚乙烯醇类共聚物-低分子电解质的影响

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The influence of the presence of low-molecular electrolytes in initial solutions of poly(vinyl alcohol) (PVA) on the results of cryotropic gelation of the polymer (gelation caused by the freezing-thawing) and on the swelling characteristics of PVA cryogels prepared in a salt-free medium were studied. The reinforcing ability of the electrolytes with respect to the gel strength for both alkaline element cations and simple low-molecular anions has been shown to be in agreement with the positions of these ions in corresponding lyotropic (Hofmeister) series. Namely, the ions (chaotropic ones), which are capable to interfere the H-bonding, disturbed somewhat the cryotropic gel-formation of PVA and facilitated the marked additional swelling of cryogels preliminary prepared in pure water medium, whereas the ions (antichaotropic ones), which are capable to promote the H-bonding, caused the formation of reinforced cryogels and resulted in the shrinking of cryogels prepared without salt additives. More pronounced effects were observed for anions as compared with cations. Some anomalous swelling behavior of PVA cryogel in Cs+-containing solutions was supposed to be associated with the formation of weak chelates. In addition to antichaotropic inorganic salts like NaF, rather high salting-out effects in respect to PVA were exhibited by well-soluble amino acid salts: glycine zwitter-ions, lysine monochlorohydrate, and monosodium aspartate. (C) 1996 John Wiley & Sons, Inc. [References: 50]
机译：聚乙烯醇（PVA）初始溶液中低分子电解质的存在对聚合物的低温凝胶化结果（冻融引起的凝胶化）以及制备的PVA凝胶的溶胀特性的影响研究了无盐培养基。对于碱性元素阳离子和简单的低分子阴离子而言，电解质相对于凝胶强度的增强能力已显示出与这些离子在相应的溶致（Hofmeister）系列中的位置一致。即，能够干扰氢键的离子（离液离子）在一定程度上扰乱了PVA的低温凝胶形成，并促进了在纯水介质中初步制备的冰凝胶的明显额外溶胀，而离子（离液离子）。能够促进氢键作用的金属，导致增强的冰晶凝胶的形成，并导致未添加盐添加剂的冰晶凝胶收缩。与阳离子相比，对阴离子观察到更明显的影响。在含Cs +的溶液中，PVA冷冻凝胶的某些异常膨胀行为被认为与弱螯合物的形成有关。除了像NaF这样的抗各向异性无机盐外，水溶性氨基酸盐还显示出对PVA相当高的盐析效果：甘氨酸两性离子，赖氨酸一氯水合物和天冬氨酸钠。 （C）1996 John Wiley＆Sons，Inc. [参考：50]

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