随机边界条件下向列相液晶微滴的蒙特卡罗模拟

Monte Carlo Simulations of Nematic Droplets Under Random Boundary Conditions

通过蒙特卡罗方法研究聚合物分散液晶(PDLC)微滴。取沿向列相液晶微滴(简称液滴)表面切向随机取向边界条件,计算了不同温度下二阶序参量〈P2〉λ和沿表面切向的内禀强度Q在液滴内不同区域的数值,发现在低温时,Q值从液滴外层到内层有逐渐减小的趋势,外层接近于1.0。同时对三维空间随机取向边界条件进行计算,进而对两种边界条件的结果做出对比和分析。发现后者的内禀强度值不存在随温度和区域的较强变化,均在0.5左右,较前者弱很多。

Monte Carlo computer simulations of nematic droplets on 2DR boundary conditions were used to mimic polymer dispersed liquid crystal（PDLC） . On 2DR boundary conditions, the random orienta- tions of the molecules at the boundary are tangential to the surface of the droplets. The second order parameters （P2）, and the values of introrse intensity Q in different shells of the droplets on 2DR boundary conditions at different reduced temperatures were calculated. It was found that the introrse intensity Q from the outer shells of the droplets to the inner shells at lower temperatures was declining. The values of Q in outer shells were close to 1. It was also assumed that the orientations of the molecules at the boundary are random in 3-dimension space（3DR boundary conditions）. The properties of the droplets at 3DR boundary conditions were also investigated. It was found that the introrse intensity for all the temperatures and shells in the case of 3DR boundary conditions are near 0. 5 and much weaker than that in the case of 2DR boundary conditions.