【作者】 孙志文；

【导师】 谢二庆；

【作者基本信息】 兰州大学 ， 凝聚态物理， 2008， 硕士

【摘要】 显示技术是当前科技发展的重要技术之一。其经历了最初的阴极射线管到现在的液晶显示和等离子显示。虽然现有的显示技术在体积和能耗方面取得了很大的突破,但人们希望显示技术得到更大发展。电润湿是利用外加电压改变液体和固体间的接触角。基于电润湿的显示具有低能耗、相应时间快以及色彩丰富等特点,它被认为是未来可能被广泛应用的显示技术之一。电润湿不仅在显示方面得到应用,还在芯片实验室等微机电系统得到广泛的应用。因此,近年来它吸引了众多研究者的关注。本论文结合实验室在电纺丝以及旋涂法等各方面的优势,在电润湿领域开展了以下研究工作:1.搭建了电润湿测试平台,该平台能够同步测量电润湿中液体的接触角和外加电压。论文使用该平台进行疏水性和电润湿的测试。2.分别用旋涂法和电纺丝法制备聚四氟乙烯膜,观察膜的疏水性。分析了旋涂法中旋转速度和温度对膜疏水性的影响;通过调节实验参数发现当旋转速度大于3000rpm且烘烤温度高于180℃时所制备的薄膜具有疏水性质。用电纺丝法制备的聚四氟乙烯薄膜不疏水,对其表面形貌进行研究后发现其结构疏松,颗粒没有完全分散开。3.制备了不同介电层的电润湿样品。为了便于对比,论文分别采用钛酸钡和二氧化钛作为电润湿的介电层。钛酸钡通过脉冲激光法沉积;而二氧化钛则通过溶胶凝胶法制备。在介电层上再旋涂一层疏水聚四氟乙烯薄膜,这样就得到不同介电层的电润湿样品。4.分析了导电液体和疏水材料之间的摩擦力对电润湿的影响,得出了接触角在外加电压大于临界电压时才开始变小的结论。临界电压取决于介电层的介电常数、厚度以及表面的摩擦系数。当外加电压初始值小于临界电压时,液体接触角不会改变直至外加电压大于临界值,摩擦力的存在使得液体接触角的变化出现突变。在对不同介电层的电润湿样品测试中都观察到了这种突变。测试还表明,钛酸钡样品的临界电压要低于二氧化钛样品的临界电压。5.分别采用NaCl溶液和CuSO₄溶液作为导电液体,在CuSO₄溶液中观察到了电润湿中的电解。实验发现低电解电压的液体在电润湿中更容易电解。更多还原

【Abstract】 Display technology is one of the important technical developments in recent years. It has experimented Cathode Ray Tube to Liquid Crystal Display and Plasma Display Panel. Although the existing display technologies have made great breakthroughs in the size and power consumption, it is hoped that further development of display technology.Electrowetting is defined as the change in solid electrolyte contact angle due to an applied potential difference between the solid and the electrolyte. Displays based on Electrowetting have a low-power, a video-rate response time, rich colors and other characteristics. Electrowetting displays are generally considered to be one of the main display technologies for the future. Applications of electrowetting are not only displays but also lab-on-a-chip and MEMS devices. It attracted many researchers in recent years. The paper has done the following research work in electrowetting with advantage of spinning and spin-coating methods in laboratory:1 Built a platform of electrowetting measurement. Contact angle and voltage can be measured synchronously in the platform. The hydrophobicity and electrowetting measurements of the paper were based on the platform.2 PTFE films were prepared by spinning and spin-coating respectively. The hydrophobicities of films were observed. The impact of rotate speed and temperature on wetting were Analyzed. It was found that the film became hydrophobic when rotate speed was up to 3000rpm and temperature was above 180℃according to adjust experiment parameters. The films prepared by spinning were hydrophilic. Their structure was very loosening and grains haven’t separated.3 Electrowetting sample based on different dielectric layer were prepared. Barium titanate and titanium dioxide were used as dielectric layer of electrowetting. Barium titanate was deposited by PLD and titanium dioxide was deposited by Sol-Gel method. The electrowetting samples with different dielectric were prepared after PTFE film was spin-coated on the dielectric layer.4 Analyzed the influence of friction between hydrophobic materials and liquid in electrowetting. Concluded the condition of contact angle change is that the applied voltage is greater than the critical voltage. The critical voltage is decided by dielectric constant, thickness and friction factor. The contact angle would not change until the voltage is greater than the critical voltage. There would be mutation because of friction. The mutation were Observed in all samples. The measurement also showed that the critical voltage of samples based on barium titanate is lower than samples based on titanium dioxide.5 NaCl solution and CuSO₄ solution were used as electrolyte in electrowetting respectively. Electrolysis was observed in electrowetting when the solution is CuSO₄. It was found that electrolyte with lower electrolysis voltage would be prone to electrolysis in experiment.更多还原