Morphological study of PS/PMMA-matrix on glass, related to vapour pressure, mass-fraction, and size

Abstract: The objective of this study is to observe how changing amount or ratio between dried mixes of poly-methyl-methacrylate and poly-styrene change the surface appearance, and how the results might inform future design of Organic photovoltaic cells, whom are based on polymer mixtures and heavenly dependent on the arrangement of polymers. An atomic force microscope was used on glass surfaces coated in a poly-methyl-methacrylate/poly-styrene matrix and dried from either dichloromethane or ethyl-acetate to determine surface appearance. Differing polymer mass-fractions or molecular weights matrices were assessed to determine their potential effects on surface domain and roughness size. In addition, an evaporation test was conducted to compare the solvent’s vapour pressure and how rates of evaporation change with the different polymer blends in solution. The result of atomic force microscope analysis pointed towards about 70% larger domains for ethyl-acetate than dichloromethane in general for the molecular weights samples, within the general trend another could be parsed; poly-styrene length is the major factor compared to poly-methyl-methacrylate for increasing domain size. When it came to mass-fractions, both poly-styrene static and poly-methyl-methacrylate static with varying poly-methyl-methacrylate and poly-styrene respectively was examined. Therein it was found that a fraction increases of poly-methyl-methacrylate shrunk domain size about 10% while increasing poly-styrene fractions grew domain sizes about 32%. However, unlike molecular weights, where surface roughness increased with longer polymers regardless if that was poly-methyl-methacrylate or poly-styrene, mass-fractions roughness always dropped whenever fraction size disparity grew, possibly due to homogenisation of the surface. In conclusion shorter and in excess polymers of poly-methyl-methacrylate produced smaller domains when paired with similar length poly-styrene in an accommodating solvent of high vapor pressure. Although lower vapour pressures are also feasible but at the cost of generally larger domain sizes.