New insights into the relationship between internal phase level of emulsion templates and gas–liquid permeability of interconnected macroporous polymers
New insights into the relationship between internal phase level of emulsion templates and gas–liquid permeability of interconnected macroporous polymers
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DOI：
10.1039/b900426b
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发表时间：
2009-11
期刊：
影响因子：
3.4
通讯作者：
Shu San Manley;Nadine Graeber;Zdenek Grof;A. Menner;G. Hewitt;F. Štěpánek;A. Bismarck
中科院分区：
文献类型：
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作者：
Shu San Manley;Nadine Graeber;Zdenek Grof;A. Menner;G. Hewitt;F. Štěpánek;A. Bismarck
相互连接的大孔聚合物可以通过由水相和单体相（通常是苯乙烯和二乙烯基苯）组成的乳液模板聚合而成，其中水相（内部）以液滴的形式存在，单体相是液滴之间的连续相。直到最近，人们还认为相互连接的大孔聚合物只能由高内相乳液（HIPE）模板聚合而成，内相水平超过74 vol%。通过增加大孔聚合物的材料密度，可以改善这种大孔聚合物的机械性能。然而，这需要减少乳液模板的内相体积。内相体积为84%至70%的乳液模板的连续有机相聚合导致聚合（聚合）hipe的产生，内相体积为70%至30%的中内相乳液在polymipe中聚合，内相体积为25%的低内相乳液在polyLIPE中聚合。所得到的大孔聚合物在机械和结构性能以及气体和汞渗透性方面进行了表征。压缩试验表明，随着材料密度的增加，材料的力学性能得到改善。气体和汞渗透性测量表明，随着乳液模板内相体积的减小，所得大孔聚合物的渗透性也随之降低。然而，令人惊讶的是，即使是由低内相乳液模板（25 vol%）制成的大孔聚合物也具有渗透性，渗透率为2.6 × 10−14m2，这表明polyLIPEs仍然是相互连接的大孔聚合物。多孔材料输运特性的重建模型表明，与大孔聚合物结构相似的多孔材料的渗透率随着孔隙率的增加呈指数增长。
Interconnected macroporous polymers can be made by polymerisation of emulsion templates consisting of an aqueous phase and a monomer phase (typically styrene and divinylbenzene) in which the aqueous (internal) phase is in the form of drops and the monomer phase is the continuous phase between the drops. Until recently it was thought that interconnected macroporous polymers could only be produced from the polymerisation of high internal phase emulsion (HIPE) templates with an internal phase level exceeding 74 vol%. Improvement of the poor mechanical performance, characteristic of such macroporous polymers, was achieved simply by increasing the material density of the macroporous polymer. However, this required a reduction in the internal phase volume of the emulsion template. Polymerisation of the continuous organic phase of emulsion templates with an internal phase volume ranging from 84 vol% to 70 vol% resulted in the production of poly(merised)HIPEs, polymerisation of medium internal phase emulsions with internal phase volume ranging from 70 vol% to 30 vol% in polyMIPEs and polymerisation of a low internal phase emulsion with an internal phase volume of 25 vol% in a polyLIPE. The resulting macroporous polymers were characterised in terms of mechanical and structural properties as well as gas and mercury permeability. Compression tests show that mechanical properties improved as the material density was increased. Gas and mercury permeability measurements show that as the internal phase volume of the emulsion template is reduced, the permeability of the resultant macroporous polymer is also reduced. However, surprisingly even macroporous polymers produced from low internal phase emulsion templates (25 vol%) were permeable with a gas permeability of 2.6 × 10−14m2 indicating that polyLIPEs are still interconnected macroporous polymers. Reconstruction modelling of the transport properties of porous materials shows that the permeability of a porous material with similar structures to that of the macroporous polymers increases exponentially with the porosity.