Osmotic and SANS observations on sodium polyacrylate hydrogels in physiological salt solutions
Osmotic and SANS observations on sodium polyacrylate hydrogels in physiological salt solutions
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DOI：
10.1021/ma000972r
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发表时间：
2000-10-31
期刊：
影响因子：
5.5
通讯作者：
Geissler, E
中科院分区：
文献类型：
--
作者：
Horkay, F;Basser, PJ;Geissler, E
通过渗透膨胀压和小角中子散射（SANS）测量，研究了在40 mM NaCl溶液中溶胀的轻度交联的完全中和的聚丙烯酸钠水凝胶中加入钙引起的体积转变。在这种可逆转变中，聚合物体积分数psi的变化超过一个数量级。从宏观测量中推导出的纵向渗透模量M-os在过渡处突然增加。散射辐射的强度可以分解为静态分量和动态分量。前者表现出孔隙散射行为，而后者服从Orstein-Zernike关系。观察到的动态部分的强度有一个最大的过渡，并表现出功能依赖于钙浓度，这是类似的渗透敏感性psi（2）/M-os，从直接渗透测量确定。
The volume transition induced by the addition of calcium into lightly cross-linked fully neutralized sodium polyacrylate hydrogels, swollen in 40 mM NaCl solutions, is investigated by osmotic swelling pressure and small-angle neutron scattering (SANS) measurements. In this reversible transition, the polymer volume fraction psi changes by more than an order of magnitude. The longitudinal osmotic modulus M-os deduced from macroscopic measurements shows an abrupt increase at the transition. The intensity of the scattered radiation can be decomposed into a static and a dynamic component. The former exhibits Pored scattering behavior, while the latter obeys an Orstein-Zernike relation. The observed intensity of the dynamic part has a maximum at the transition and exhibits a functional dependence on the calcium concentration, which is similar to that of the osmotic susceptibility psi (2)/M-os, determined from direct osmotic measurements.