我們展示了對稱、弱分離的嵌段共聚物薄膜（聚苯乙烯 -b-甲基丙烯酸甲酯） 與低分子量和高分子量同聚物（ PS2.8k和 PS17k）混合物的形態觀察和結構表徵。 這些混合物薄膜都支撐在矽基板上。 PS-b-PMMA/PS的混合物薄膜以 70/30和 50/50的重量比 製 備。在這兩個 比例下，薄膜形成了平行圓柱體結構。混合物薄 膜的初始厚度由聚合物濃度和旋轉速率控制。我們在兩個溫度下進行熱退火： 230和 270 oC。在這兩個目標溫度下，使用了兩個熱 歷 史： ：(i) 1小時， ，(ii) 48小 時。熱退火從 310 oC 10分鐘）的旋轉狀態或熔融狀態開始。對混合物薄膜進 行了光學顯微鏡（ OM）、掃描電子顯微鏡 SEM）和低入射角 X射線散射 GISAXS）的深入結構分析。無論熱 歷 史如何， PS-b-PMMA/PS2.8k混合物薄膜 都形成了孔洞和圓柱體的混合結構。這個結果表明結構處於平衡狀態。由於孔 洞和圓柱 體是水平排列的， PS-b-PMMA/PS2.8k薄膜的自由表面總是由一層薄的 孔洞層主導，該層位於平行圓柱體的頂部。通過角度依賴的 GISAXS進一步研 究了平行圓柱體的空間排列 發現了具有 C2mm對稱性的變形六角陣列。;We have demonstrated morphological observations and structural characterization for thin films of a symmetric, weakly segregated block copolymers—poly (styrene-b-methyl methacrylate) blended with low-molecular -weight and high-molecular-weight homopolymers (PS2.8k and PS17k), respectively. The blend films were all supported on silicon substrates. PS-b-PMMA/PS blends were prepared at weight fractions of 70/30 and 50/50. At the two ratios, the films form parallel cylinders. The initial thickness of blend films is controlled by polymer concentrations and spin rates. Two temperatures were used for thermal annealing: 230 and 270 oC Two thermal histories were used for thermal annealing at the two target temperatures: (i) 1 hour, (ii) 48 hours. The thermal annealing starts either from a spun state or a melt state at 310 oC (10 min). The in-depth structural analysis of the blended film was carried out by optical microscopy (OM), scanning electron microscopy (SEM), and low-grazing angle X-ray scattering (GISAXS). The PS-b-PMMA/PS2.8k blend films formed mixtures of perforations and cylinders regardless of the thermal histories. This result indicate that the structures are in an equilibrium state. Since the perforations and cylinders orient horizontally, the free surface of the PS-b-PMMA/PS2.8k films is always dominated by a thin layer of perforations, which sit on top of parallel cylinders. The spatial packing of parallel cylinders was further studied by angle-dependence GISAXS. Deformed hexagonal arrays with C2mm symmetry were found.
