纳米及亚微米尺寸的光电聚合物晶体材料具有优良的电子传输性能，其力学稳定性是影响应用的重要因素，直接在空气相中研究其纳米力学性质是一个非常有意义而又充满挑战性的课题。本项目拟选取导电聚合物P3HT为模型体系，结合原子力显微镜的扫描定位和单个分子的操纵等功能，开展以下研究：第一，通过优化实验条件减小水膜粘附力的影响，建立空气相单分子力谱方法；第二，探索晶体结构、温度和介质对单分子熔融解链和纳米力学性质的影响，揭示界面相互作用和晶格相互作用的分子机制；第三，建立单分子和介观力学性质之间的关联，同时尝试利用单分子和介观平衡态力学性质来预测宏观力学性质。通过本项目的实施，不仅可以发展一种直接在空气相中研究高分子凝聚态纳米力学的方法，还将有利于建立结构、结晶性和多尺度力学性质之间的关系，为P3HT晶体材料的设计及结构调控提供参考。

The high-performance carrier mobilities of conjugated polymer semiconductors in nano and sub-micron scale derive from the ability to crystallize. And the mechanical properties of conjugated polymer crystals have a significant impact on their optoelectronic applications. Therefore, the study in their nano-mechanical properties in air is extremely critical and challenging. In the present project, poly(3-alkylthiophenes) (P3HT) crystals are researched as a model system by a combination of atomic force microscopy (AFM) and single-molecule force spectroscopy (SMFS). The projects are as follows:.1) By decreasing the adhesion force of water film, the AFM-based SMFS is extended to the investigation of polymer interactions in air..2) The effects of crystal structure, tempreture and medium on single-molecule melting and nanomechanics are investigated to reveal the mechanism of interface interaction and lattice interaction..3) We will establish the relationship between single-molecule and mesoscopic mechanical properties and also try to predict the bulk mechanical performance by single-molecule and mesoscopic mechanical properties in equilibrium..The performing of this project can establish a novel approach to investigate polymer nanomechanics in condensed state in air, and go one step further to represent the relationship between structure，crystallization and multi-scale mechanical properties, which could provide strategies for design and structural modulation of P3HT crystalline materials.