Department of Chemical Engineering, Massachusetts Institute of Technology, USA.
ACS Nano. 2010 Jul 27;4(7):4308-16. doi: 10.1021/nn101033y.
We have demonstrated the utility of hollow silica nanoparticles in fabricating conformal thin film nanoporous antireflection (AR) coatings on both poly(methyl methacrylate) (PMMA) and glass substrates. Layer-by-layer (LbL) assembly was successfully used to produce ultrathin AR coatings on planar and textured surfaces. Hollow silica nanoparticles were synthesized to extend the range of apparent refractive indices possible in an AR coating, enabling the design of both single index and graded index AR coatings on PMMA substrates. The diameter and shell thickness of the silica nanoparticles are the two independent, controllable parameters that we manipulated to tune the refractive index of the coating. The AR coatings reduced the minimum reflection of PMMA from 7% to 0.5%, while the maximum transmission increased from 92% to 98% at the optimized wavelength region that could be adjusted from the near UV into the visible. Cross sectional SEM showed that conformal coatings can be achieved on grooved PMMA Fresnel lenses. AFM was used to study surface topography on flat substrates.
我们已经证明了中空硅纳米粒子在制备聚甲基丙烯酸甲酯（PMMA）和玻璃基底上的共形薄膜纳米多孔抗反射（AR）涂层方面的实用性。层层（LbL）组装成功地用于在平面和纹理表面上制备超薄 AR 涂层。中空硅纳米粒子的合成扩展了 AR 涂层中可能的表观折射率范围，使 PMMA 基底上的单折射率和梯度折射率 AR 涂层的设计成为可能。硅纳米粒子的直径和壳厚度是我们操纵的两个独立的、可控制的参数，用于调整涂层的折射率。AR 涂层将 PMMA 的最小反射率从 7%降低到 0.5%，而最大透过率从 92%增加到 98%，在可从近紫外光调节到可见光的优化波长范围内。横截面 SEM 显示，共形涂层可以在槽 PMMA 菲涅尔透镜上实现。AFM 用于研究平面基底上的表面形貌。
