【作者】 郭颖；

【导师】 俞建勇； 张菁；

【作者基本信息】 东华大学 ， 纺织材料与纺织品设计， 2009， 博士

【摘要】 一维单晶聚合物纳米材料是我们追求的理想特性聚合物。如何运用简单有效的方法进行准一维单晶聚合物纳米材料的可控制备是本领域研究的重要课题。本文深入探索了常压低温等离子体定向聚合晶体成型新方法。主要研究了单晶氟碳聚合物纳米管、棒的聚合成型,重点探索等离子体中活性团簇粒子定向聚合结晶的机制,剖析了在常温、常压、无外加催化剂、无外加限域模板下快速进行聚合成型的微观过程和机理,掌握其关键控制因素,达到了对聚合物纳米管、棒的化学成分、结构、纳米晶粒尺度、结晶等的可控制备,获得具有均匀尺度及崭新特性的氟碳有机纳米管、棒。这将对发展其它一维单晶聚合物纳米结构的制备和应用具有普遍推广意义。论文主要研究内容包括以下几个方面:第一部分:研究了常压等离子体放电特性在常压等离子体定向聚合晶体过程中,等离子体的放电特性与定向聚合沉积过程密切相关,也极大的影响着纳米晶体沉积薄膜的结构特性。因此,本论文首先研究了常压等离子体放电特性;通过建立大气压下氩气中二维理论数值模型,研究了同轴圆筒状反应装置中介质阻挡放电（DBD）的放电特性,数值模拟结果揭示了等离子体中放电通道的形成与发展过程;包括电子、离子浓度和表面电荷密度随空间和时间的分布,及其与空间电场的对应关系,说明了在介质表面附近区域的场强有明显的梯度变化,这是决定定向聚合晶体过程的主导因素。第二部分:研究了氟碳纳米晶体结构薄膜的生长过程、影响因素及机理通过SEM、TEM对薄膜结构分析表明,氟碳纳米晶体结构薄膜主要由纳米管、纳米棒和纳米颗粒组成的混合体。实验中影响氟碳纳米晶体生长形态的重要工艺参数有放电功率、放电时间以及Ar和C₆F₁₄混合气体流量比R。通过调整放电参数,成功实现了氟碳单晶纳米管和单晶纳米棒的可控快速（十几秒到三分钟）制备;另外通过对XRD和TEM的结果分析,说明常压DBD等离子体聚合的氟碳纳米晶体结构薄膜结晶良好并且是由两套晶体结构组成的混合结构:一维单晶纳米棒及纳米晶体颗粒膜所属的六方晶系;一维单晶纳米管所属的密堆六方晶系。通过XPS和FTIR分析表明:放电功率是影响氟碳纳米晶体结构薄膜特性的重要因素。结合实验和模拟分析结果,提出了适合常压低温等离子体聚合碳氟纳米晶体结构薄膜的“受梯度电场限制的一维活化生长模型”。第三部分:研究了氟碳纳米晶体结构薄膜的热性能以及织物表面功能化。通过PLM和TGA研究了氟碳纳米晶体结构薄膜的熔融过程,在室温（36.7℃）下观察到棒状的氟碳晶体,而在100℃和250℃两个温度附近出现了较明显的熔融分解过程,特别是当温度达到350℃,仍可得到部分晶体的双折射存在。另外,利用常压等离子体Ar/C₆F₁₄快速聚合涂层功能化,赋予棉织物表面拒油拒水特性,并对整理后的织物进行一系列的性能测试,包括拒水性、拒油性、透湿性、手感柔软性等。通过对整理后的棉织物各方面性能的变化情况,讨论了常压DBD氟碳涂层对织物性能的影响。特别是获得了与商用ScotchgardTM防污保护剂涂覆的织物相当的拒水特性。更多还原

【Abstract】 One dimensional (1D) nanomaterials have been attracting much attention recently for their tremendous potential applications in nanoscience and nanotechnology. The 1D nanomaterials in terms of nanotube, nanowire and nanobelts are widely employed in nannodevices, photoelectronic devices and sensors for their specific physical and chemical characteristics. It is accepted that the preparation and characterization of nanomaterials both are most important issues. In nanomaterials preparation, plasma technologies, especially nonthermal atmospheric-pressure plasmas, are considered to be a feasible and effective method with low-cost for forming crystal nanostructures, in which, the nanostructures are formed with process of assembling or etching by electrons, atoms, ions, excited molecules generated in plasma.In this thesis, a novel method of "atmospheric oriented plasma polymerizations" is developed for forming single crystalline fluorocarbon polymer nanotubes and/or nanorods, in which, an asymmetrical electrical field with gradient in plasma is used for generating and polarizing the reactive species. The results are listed briefly as following:PartⅠ: Characterization of plasmas dischargeThe experimental set-up applied in our study is a dielectric-barrier cylindrical reactor, the discharge characteristics in which are investigated with electrical measurements and numerical simulation. The measured waveforms of applied voltage and discharge current suggest that the discharge is a typical dielectric-barrier discharge (DBD) and is filled with filaments. Further studies on discharge characteristics are carried out with a numerical simulation of particle in cell (PIC). The dynamics and evolution of microdischarge are demonstrated by spatial-temporal distribution of electron density, ion density, surface charge density and electric field. It shows that these charged particles in discharge are all accumulated in the regime above dielectric layer surface at anode, which suggests an asymmetrical electric field with gradient around anode.PartⅡ: Fabrication and manipulation of morphology in PTFE-like polymer nanocrystals filmsWith atmospheric DBDs, the PTFE-like polymer nanocrystals films can be obtained within a short period of time ranging from a few seconds to several minutes, in which, different morphology nanocrystals in terms of nanorods, nanoparticles and nanotubes are all found by SEM. Furthermore, it is confirmed that these nanocrystals are in phase of single-crystaline by TEM and XRD results. Additionally, the dependence of nanocrystalline morphology and crystallinity on discharge parameters of discharge time duration, flow ratio of monomer to carrier gas and discharge dissipated power were investigated. The results demonstrate that the physical morphology and structures could be manipulated with the discharge conditions, especially for the oriented plasma polymerization. It suggests that this novel polymerization method offers a rapid and effective way for fabricating polymeric nanocrystallines.For better understanding of underpinning film growth mechanism, the procedure of nanocrystalline film synthesis is discussed, correlated to discharge characteristics. It suggests that the asymmetrical gradient electrical field plays an important role on growth of -one dimensional nanocrystals oriented plasma polymerizations, based on which, the growth model named "one dimensional activated growth model limited by gradient electrical field" is proposed for explanation of film growth mechanism.PartⅢ: Hydrophobic properties and thermal properties of nanocrystals filmsThe result of PLM and TGA indicates that the title compound keeps stable up to temperature of 350°C. The contact angle of the water and 1-bromonaphthalene on coated cotton fabric was found to be 133°and 124°, separately. The surface morphology of the coating was examined through SEM. It was found that cotton fabric surface was tightly adhered to a thin film packed by nano-particles with diameter from 10 nm to 200 nm. This process showed potential applications in continuous coating of textiles with functional nano-particulate polymers, without changing their performance of softness.更多还原