Direct observation of critical Casimir effect using capacitance measurements for thin polymer films

本研究的目的是阐明卡西米尔力存在于具有关键组分的聚合物共混物薄膜中。我们对PEMS质量分数为55%的聚（二甲基硅氧烷）/聚（乙基甲基硅氧烷）薄膜在100kHz时的电容进行了精确测量。在玻璃化转变温度以上，电容随温度的升高而减小，然后在临界温度附近呈现平稳状态。这一结果表明，在两个电极之间存在一种吸引的相互作用。引力的起源可能是由于卡西米尔力，尽管详细的测量还不能成功地完成。其次，我们利用介电光谱技术测量了不同厚度的聚苯乙烯薄膜之间的α过程动力学。这个实验对于理解卡西米尔效应的微观机制是很重要的。

The purpose of the present study was to elucidate the existence of Casimir force for thin films of polymer blends with a critical component. We made precise measurements of electric capacitance at 100kHz for thin films of poly(dimethyl siloxane)/poly(ethyl methyl siloxane) with 55 % wt fraction of PEMS. The electric capacitance decreases with increasing temperature above the glass transition temperature and then shows a plateau around the critical temperatures. This results suggest that there is an attractive interaction between two electrodes. The origin of the attractive force might be due to the Casimir forces, although the detailed measurements could not yet be done successfully. Secondly, we measured the dynamics of alpha-process of poly(2-chlorostyrene) thin films between two polystyrene thin films with various thicknesses using dielectric spectroscopy for annealing process. This experiment will be important for understanding of the microscopic mechanism of the Casimir effect.