New insights on estimating pore size distribution of latex particles: Statistical mechanics approach and modeling

Abstract

New statistical mechanics approach for pore size distribution applied in wide the relative pressure range is proposed. The new proposed model was applied to nitrogen adsorption-desorption isotherms at 77 K onto five functionalized polystyrene latices. Results showed that the proposed model can reproduce all results found by traditional methods such as NLDFT, BJH and VBS where some of them can be applied only for a specific range of pore size. A segmentation procedure is adopted and it is shown that the corresponding algorithm can be successfully applied for determining pore size distributions over a wide range of pore size. When this method is applied an isotherms Type II and III (materials with larger mesopores and/or macropores) gives additional information that is not obtained with the other methods. The obtained results showed that the copolymerization plays an important role in the porosity and the specific surface area, whereas, the high polydispersity index, PDI, can reduce the porosity. The samples studied within the present work present small and large mesopores and even macropores as it is suggested by the new proposed model, and part of this porosity could be related to the interparticle and also to the intraparticle porosity.