Thermal field-flow fractionation of colloidal materials: Methylmethacrylate-styrene linear di-block copolymers
Thermal field-flow fractionation of colloidal materials: Methylmethacrylate-styrene linear di-block copolymers
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胶体材料的热场流分级：甲基丙烯酸甲酯-苯乙烯线性二嵌段共聚物
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发表时间：
1997
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影响因子：
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通讯作者：
M. Martin
中科院分区：
文献类型：
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作者：
C. V. Batten;M. Hoyos;M. Martin
本文以甲基丙烯酸甲酯-苯乙烯线性二嵌段共聚物为模型，采用热场流分馏（thermal field-flow fractionation，FFF）方法，分别在甲苯和四氢呋喃（THF）中研究了温度、摩尔质量和化学组成对其Soret系数sT的影响。采用一个新发展的热FFF保留模型，考虑了FFF基本参数λ随温度的变化，研究了Soret系数对温度的依赖性。结果表明，该系数随温度的升高近似线性地减小。在恒定的化学组成和温度下，sT与摩尔质量呈幂律关系，指数为0.55。在恒定的摩尔质量和温度下，sT随着共聚物组合物中苯乙烯重量百分比的增加而单调降低。在300 K时，THF中的sT值略大于甲苯中的sT值。
SummaryModel methylmethacrylate-styrene, linear di-block, copolymers were used to investigate the respective influnnces of temperature, of molar mass and of chemical composition on their Soret coefficient, sT, by means of thermal field-flow fractionation (thermal FFF) in toluene and in THF. A recently developed thermal FFF retention model, which takes into account the variation of the basic FFF parameter λ with temperature, is applied to investigate the dependence of the Soret coefficient on temperature. It is found that the coefficient decreases approximately linearly with increasing temperature. At constant chemical composition and temperature, sT exhibits a power law dependence on molar mass with an exponent É ã 0.55. At constant molar mass and temperature, sT decreases monotonously with increasing weight percent styrene in the copolymer composition. At 300 K, sT values are slightly larger in THF than in toluene.