Pressure effects on the inhomogeneities of environmentally sensitive polymer gels
Pressure effects on the inhomogeneities of environmentally sensitive polymer gels
复制标题
压力对环境敏感聚合物凝胶不均匀性的影响
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
C. Nakamoto
中科院分区：
文献类型：
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作者：
M. Shibayama;S. Takata;C. Nakamoto
通过中子小角散射研究了凝胶制备过程中的压力对非均匀性的影响。聚（N-异丙基丙烯酰胺）（PNIPA）凝胶是一种发生体积转变的温敏性聚合物凝胶，在0.1 ~ 300 MPa的压力范围内制备了PNIPA凝胶。散射强度随着Pprep的增加而增加，直到200 MPa，然后通过Pprep的进一步增加而降低。通过静态和动态散射因子的比值评估的不均匀性程度表现出与系综平均光散射强度E相似的行为。从溶胀热力学的角度讨论了凝胶不均匀性的物理意义。结果表明，溶胀度的增加不是由于PNIPA与水的可溶解性的增加，而是由于不均匀性的增加。
The effects of pressure at gel preparation on the inhomogeneities were investigated by small-angle neutron scattering. Poly(N-isopropylacrylamide) (PNIPA) gels, known as thermosensitive polymer gels undergoing volume transition, were prepared at various pressures ranging from 0.1 to 300 MPa. The scattering intensity increased with increasing Pprep, up to 200 MPa, then decreased by further increase in Pprep. The degree of inhomogeneities evaluated by the ratio of the static and dynamic correlators exhibited a similar behavior to that of the ensemble average light scattered intensity, E. The physical meaning of the gel inhomogeneities is discussed from the viewpoint of swelling thermodynamics. It will be shown that the increase in the swelling degree is due not to an increase in the miscibility of PNIPA with water but to the increase in inhomogeneities.