Control of the Porous Structure of Polystyrene Particles Obtained by Nonsolvent Induced Phase Separation
Control of the Porous Structure of Polystyrene Particles Obtained by Nonsolvent Induced Phase Separation
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DOI：
10.1021/acs.langmuir.7b02802
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发表时间：
2017-11-21
期刊：
影响因子：
3.9
通讯作者：
Fairdough, J. Patrick A.
中科院分区：
文献类型：
--
作者：
Bianco, Antonino;Burg, Stephanie L.;Fairdough, J. Patrick A.
采用非溶剂诱导相分离法（NIPS）从三元聚合物溶剂-非溶剂（聚苯乙烯-甲苯-乙醇）体系中制备了多孔聚苯乙烯微球，并用扫描电子显微镜（SEM）和小角X射线散射（SAXS）技术对其进行了表征。这项研究提供了证据之间的联系的多孔聚苯乙烯颗粒的结构形态和聚苯乙烯浓度在初始溶液中。对于聚合物量低于临界链重叠浓度C* 的体系，观察到孔径与聚合物浓度之间的倒数关系。在C* 以上，这种关系破裂。孔隙率和聚合物浓度之间的倒数关系可用于促进孔隙尺寸的精细控制。我们证明，所观察到的孔径和聚合物浓度之间的倒数关系以及与非溶剂的相对量存在于系统中的相分离过程的开始，孔径可以减小，因此，孔表面积可以增加，通过降低初始溶液中的聚合物浓度或通过降低样品组合物中的聚合物分子量。
Porous polystyrene microspheres were produced by a process of nonsolvent induced phase separation (NIPS) from ternary polymer solvent nonsolvent (polystyrene toluene ethanol) systems and characterized by scanning electron microscopy (SEM) and small angle X-ray scattering (SAXS) techniques. This study provides evidence for a link between the structural morphology of the porous polystyrene particles and the polystyrene concentration in the initial solutions. A reciprocal relationship between pore diameter and polymer concentration was observed for the systems with the polymer amount below the critical chain overlap concentration, C*. Above C*, this relationship breaks down. The reciprocal relationship between porosity and polymer concentration can be used to facilitate the fine control of the void size. We demonstrate that the observed reciprocal relationship between pore diameter and polymer concentration correlates well with the relative amount of nonsolvent present in the system at the onset of the phase separation process, The pore size can be reduced and, consequently, the pore surface area can be increased either by reducing the polymer concentration in the initial solution or by decreasing the polymer molecular weight in the sample composition.