Effect of solvents on the morphology of PMMA films fabricated by spin-coating

Abstract A method to produce thin layer of PMMA (poly (methyl methacrylate) films by spin coating is reported. PMMA is dissolved in xylene, a mixture of MIBK-xylene and chloroform. Varying the PMMA concentration and spin-coating speeds controls the thickness of the PMMA films. Using chloroform as solvent evidenced thickness around 10 μm. This thickness is suitable for core of optical polymeric films. These PMMA films with lower roughness are treated with CHF3 plasma to produce the cladding. The morphology of PMMA films is analyzed by atomic force microscopy and scanning electron microscopy. Profilometry, metricon and contact angle analysis are associated with the effective parameters in roughness and their effect before and after plasma treatment. Gel permeation chromatography (GPC) is used for estimating molecular weights of PMMA.摘要 本文报道了一种通过旋涂法制备聚甲基丙烯酸甲酯（PMMA, poly(methyl methacrylate)）薄层薄膜的方法。将PMMA溶解于二甲苯（xylene）、甲基异丁基酮（MIBK, methyl isobutyl ketone）-二甲苯混合溶剂以及三氯甲烷（chloroform）中，通过调整PMMA浓度与旋涂转速即可调控PMMA薄膜的厚度。以三氯甲烷为溶剂时，所制得的薄膜厚度约为10 μm，该厚度适配于光学聚合物薄膜的芯层制备。将粗糙度更低的该类PMMA薄膜经三氟甲烷（CHF₃）等离子体处理后，可制备得到包层。采用原子力显微镜（atomic force microscopy）与扫描电子显微镜（scanning electron microscopy）对PMMA薄膜的形貌进行表征分析。借助轮廓仪（profilometry）、Metricon设备与接触角分析，探究与粗糙度相关的有效参数及其在等离子体处理前后的变化规律。采用凝胶渗透色谱（GPC, gel permeation chromatography）对PMMA的分子量进行估算。