Department of Chemical Engineering, Polymer & Composite Engineering Group, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Langmuir. 2010 Jun 1;26(11):8836-41. doi: 10.1021/la9046066.
Particle-stabilized high internal phase emulsions have been used to synthesize tough and very high porosity macroporus polymers with a closed-cell pore structure. In this study, we show that Pickering water-in-oil emulsion templates with up to an 85 vol % internal phase can be stabilized by only 1 wt % of titania particles with their surfaces suitably modified by the adsorption of 3.5 +/- 0.5 wt % oleic acid. The pore structure and mechanical properties of the resulting macroporous polymers were tailored by altering the internal phase volume ratio of the emulsion template and the titania particle concentration used to stabilize the emulsion templates. The pore size and pore size distributions increase with increasing internal phase volume of the emulsion template as well as decreasing titania particle concentration used to stabilize the emulsion template. The mechanical properties, namely, Young's modulus and the crush strength of the macroporous polymers, increased with decreasing porosity and increasing foam density. The toughest macroporous polymer had the lowest porosity but also the smallest pore size and narrowest pore size distribution.
粒子稳定的高内相比乳液已被用于合成具有闭孔结构的坚韧和超高多孔大孔聚合物。在这项研究中，我们表明，通过吸附 3.5±0.5wt%油酸适当改性表面，仅需 1wt%的二氧化钛颗粒即可稳定高达 85vol%内相比的 Pickering 水包油乳液模板。通过改变乳液模板的内相比和用于稳定乳液模板的二氧化钛颗粒浓度，可以调节所得大孔聚合物的孔结构和机械性能。孔径和孔径分布随乳液模板内相比的增加以及用于稳定乳液模板的二氧化钛颗粒浓度的降低而增大。机械性能，即杨氏模量和大孔聚合物的抗压强度，随孔隙率的降低和泡沫密度的增加而增加。最坚韧的大孔聚合物具有最低的孔隙率，但也具有最小的孔径和最窄的孔径分布。
