Dilute solution behaviour of sodium polyacrylate chains in aqueous NaCl solutions
Dilute solution behaviour of sodium polyacrylate chains in aqueous NaCl solutions
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DOI：
10.1016/j.polymer.2003.07.005
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发表时间：
2003-11
期刊：
影响因子：
4.6
通讯作者：
R. Schweins;J. Hollmann;K. Huber
中科院分区：
文献类型：
--
作者：
R. Schweins;J. Hollmann;K. Huber
结合静态和动态光散射被用来在添加NaCl的稀水溶液中的各种聚丙烯酸钠样品。NaCl含量的增加导致溶剂质量的降低。基于这些发现，选择两种溶剂条件用于详细研究作为摩尔质量Mw的函数的线团尺寸：0.1 M NaCl水溶液代表化学性能良好的溶剂，1.5 M NaCl水溶液接近于Θ-溶剂。如果NaCl含量保持在0.1 M ≤[NaCl]≤1.5 M的范围内，则对于相应的中性单体，单个Kuhn链段长度lk=4.2 nm和排除体积参数ω0=−0.04 [Muthukumar et al. Macromolecules 30; 1997：8375]能够充分描述作为摩尔质量和添加盐含量的函数的螺旋膨胀。对于低盐含量，Muthukumar基于排除体积参数ω0、Kuhn段长度lk和有效电荷密度f的方法变得越来越不合适。
Combined static and dynamic light scattering was used to characterise a variety of sodium poly(acrylate) samples in dilute aqueous solutions with added NaCl. An increase of the NaCl content resulted in a decrease of the solvent quality. On the basis of these findings, two solvent conditions were selected for a detailed investigation of the coil size as a function of the molar mass Mw: aqueous 0.1 M NaCl represents a thermodynamically good solvent and aqueous 1.5 M NaCl is close to a Θ-solvent. If the NaCl content was kept within this range of 0.1M≤[NaCl]≤1.5 M, a single Kuhn segment length of lk=4.2 nm and an excluded volume parameter of ω0=−0.04 for the corresponding neutral monomer [Muthukumar et al. Macromolecules 30; 1997: 8375] were able to adequately describe coil expansion as a function of the molar mass and the content of added salt. Towards lower salt contents, Muthukumar's approach which is based on the excluded volume parameter ω0, the Kuhn segment length lkand an effective charge density f became increasingly inadequate.