Karikari Afia S, Williams Sharlene R, Heisey Cheryl L, Rawlett Adam M, Long Timothy E
Department of Chemistry, Macromolecules and Interfaces Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061,USA.
Langmuir. 2006 Nov 7;22(23):9687-93. doi: 10.1021/la0603020.
Self-assembly processes and subsequent photo-cross-linking were used to generate cross-linked, ordered microporous structures on the surfaces of well defined four-arm star-shaped poly(D,L-lactide) (PDLLA) thin films. The four-arm star-shaped PDLLAs were synthesized using an ethoxylated pentaerythritol initiator. Solutions of the PDLLAs were cast in a humid environment, and upon solvent evaporation, ordered honeycomb structures (or breath figures) were obtained. Correlations between molar mass, polymer solution viscosity, and pore dimensions were established. The average pore dimension decreased with increasing polymer solution concentration, and a linear relationship was observed between relative humidity and average pore dimensions. Highly ordered microporous structures were also developed on four-arm star-shaped methacrylate-modified PDLLA (PDLLA-UM) thin films. Subsequent photo-cross-linking resulted in more stable PDLLA porous films. The photo-cross-linked films were insoluble, and the honeycomb structures were retained despite solvent exposure. Free-standing, structured PDLLA-UM thin films were obtained upon drying for 24 h. Ordered microporous films based on biocompatible and biodegradable polymers, such as PDLLA, offer potential applications in biosensing and biomedical applications.
利用自组装过程和随后的光交联，在定义明确的四臂星形聚（D，L-丙交酯）（PDLLA）薄膜表面生成交联的有序微孔结构。使用乙氧基化季戊四醇引发剂合成四臂星形PDLLA。将PDLLA溶液浇铸在潮湿环境中，溶剂蒸发后，得到有序的蜂窝状结构（或呼吸图案）。建立了摩尔质量、聚合物溶液粘度和孔径之间的相关性。平均孔径随聚合物溶液浓度的增加而减小，并且观察到相对湿度与平均孔径之间存在线性关系。在四臂星形甲基丙烯酸酯改性的PDLLA（PDLLA-UM）薄膜上也形成了高度有序的微孔结构。随后的光交联产生了更稳定的PDLLA多孔膜。光交联膜不溶于水，尽管暴露于溶剂中，蜂窝状结构仍得以保留。干燥24小时后获得了独立的结构化PDLLA-UM薄膜。基于生物相容性和可生物降解聚合物（如PDLLA）的有序微孔膜在生物传感和生物医学应用中具有潜在应用。
