不同制备条件对聚偏氟乙烯纳米线生长的影响

为提高铁电聚合物聚偏氟乙烯(PVDF)的压电性能,利用纳米限域效应,采用模板直接浸润法,将多孔氧化铝(AAO)模板在不同浓度的PVDF的DMF溶液中自然浸润,并添加聚乙烯吡咯烷酮(PVP)作为表面修饰剂,制备了一维材料PVDF纳米线。分别研究了浸润温度、溶液浓度及表面修饰剂等因素对PVDF纳米线生长过程的影响。通过FTIR、SEM、XRD等对样品的形貌结构及性能进行了表征,进一步讨论了AAO模板中PVDF纳米线的生长机制。结果表明:模板法生长的PVDF纳米线形貌主要受溶液浓度的影响,并且当浓度为0.10 g/m L时形貌较优,其平均长度为50μm,平均直径为180 nm,与AAO模板孔径尺寸相当;表面修饰剂PVP可在一定程度上防止纳米线团聚并且优化其尺寸均一性;AAO模板中生长的PVDF纳米线由于纳米限域效应优先向β晶相结晶,并且在生长过程中PVDF并未参与任何化学反应。

Effect of Different Preparation Conditions on The Growth of PVDF Nanowire

PVDF-templated nanowires were prepared directly through a template infiltration method in the anodic porous alumina ( AAO ) membranes with the use of nano-confinement effect for the purpose of improving the piezoelectric properties of PVDF. PVDF was dissolved in N, N-dimethyl-formamide ( DMF ) in different concentration, and then different solutions were obtained. During this process, the polyvinylpyrrolidone ( PVP) acted as a surface modifying agent. The effects of in-filtration temperature, concentration of solution and surface modifying agent on the growth of PVDF nanowires were studied. In the meantime, the growth process and mechanism of PVDF nanowires were investigated by FTIR, SEM, XRD, and so on. The results show that the concentration of solu-tion is the main factor that affects the morphology of the nanowires. Moreover, the optimal morpholo-gy is obtained when the concentration is 0. 10 g/mL, with an average length of 50 μm and an aver-age diameter of 180 nm, equated with the pore size of AAO template. In a certain extent, PVP can prevent the agglomeration and optimize the size of the nanowires. Besides, the PVDF-templated nanowires preferentially crystallize to the β-phase due to the nano-confinement effect, however, there is no chemical reaction during this process.