RUI: Poly (vinyl alcohol) Thin Film Dewetting by Controlled Directional Drying

RUI：通过受控定向干燥进行聚（乙烯醇）薄膜去湿

• 批准号: 1807186
• 负责人: Wei Chen
• 金额: $ 25.8万
• 依托单位: Mount Holyoke College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807186&HistoricalAwards=false
• 关键词: RUI; Poly; vinyl; alcohol; Thin

Part 1: NON-TECHNICAL SUMMARYPolymer thin films are ubiquitous in everyday life. Typically, thin-film stability is desirable, such as in the application of coating materials. However, controlled dewetting or thin-film rupture can also be beneficial, for example in printing and other lithographic processes. Most of the existing studies have involved nonvolatile and nonpolar thin films. The stability of polymer thin films prepared from a volatile and polar liquid, such as water, has practical and fundamental significance and should be investigated. This research involves the fabrication of thin films of poly(vinyl alcohol) (PVOH), a water-soluble and non-toxic polymer, on silicone-coated silicon substrates using a new method called adsorptive spin casting. This method allows the spontaneous adherence of PVOH polymer to the silicone surfaces from water as well as the controlled rupture of PVOH thin films due to directional water evaporation. The study will systematically investigate under- or unexplored areas in polymer thin film stability, such as the (de)stabilization effect of a polar solvent, unconventional thin-film rupture patterns, and the effects of substrate mobility and polarity. As an educator and a female scientist in the longest-standing liberal arts college for women, the PI is committed to improving the representation and retention of women in the STEM disciplines. She will recruit and mentor a diverse group of undergraduate women to carry out new, relevant, publishable, and productive research proposed herein. With the proper structure, challenge and support, the students will gain competency and confidence for their future endeavors in the STEM fields.Part 2: TECHNICAL SUMMARYStability and controlled dewetting of polymer thin films have practical, technological, and fundamental significance. Studies of polymer thin films prepared from aqueous solution have been limited due to the particular challenges involved in elucidating the effects of drying dynamics and solvent polarity on thin-film stability. In the proposed research, poly(vinyl alcohol) (PVOH) thin-film dewetting on silicon wafer-supported polydimethylsiloxane (PDMS) will be studied using a new fabrication method, adsorptive spin casting. This method combines the spontaneous adsorption of PVOH at the PDMS-solution interface and the generation of ordered PVOH dewetting patterns by directional drying. PVOH is chosen because of its tunable crystallinity which will allow the study of a range of dewetting morphologies, from conventional droplets to structures with unique fractal features. Silicon wafer-supported PDMS is the substrate of choice since it will permit the probing of substrate mobility and polarity. The novelties of the research include the design of a new polymer thin-film fabrication method and the systematic exploration of relevant yet under-explored areas in polymer thin-film stability. As an educator and a female scientist in the longest-standing liberal arts college for women, the PI is committed to improving the representation and retention of women in the STEM disciplines. She will recruit and mentor a diverse group of undergraduate women to carry out new, relevant, publishable, and productive research proposed herein. With the proper structure, challenge and support, the students will gain competency and confidence for their future endeavors in the STEM fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第1部分：非技术总结聚合物薄膜在日常生活中无处不在。通常，薄膜稳定性是期望的，例如在涂覆材料的应用中。 然而，受控的去湿或薄膜破裂也可以是有益的，例如在印刷和其他光刻工艺中。现有的研究大多涉及非挥发性和非极性薄膜。由水等挥发性极性液体制备的聚合物薄膜的稳定性具有现实和基础意义，应该进行研究。这项研究涉及使用一种称为吸附旋转浇铸的新方法在有机硅涂层的硅衬底上制造聚乙烯醇（PVOH）薄膜，PVOH是一种水溶性和无毒的聚合物。该方法允许PVOH聚合物从水中自发粘附到有机硅表面，以及由于定向水蒸发而导致的PVOH薄膜的受控破裂。该研究将系统地调查下或未开发的领域在聚合物薄膜的稳定性，如（去）稳定的极性溶剂的影响，非常规的薄膜破裂模式，以及基板的流动性和极性的影响。作为历史最悠久的女子文理学院的教育家和女科学家，PI致力于提高妇女在STEM学科的代表性和保留率。她将招募和指导一群不同的本科女性，以开展本文提出的新的，相关的，可持续的和富有成效的研究。通过适当的结构、挑战和支持，学生将获得在STEM领域未来努力的能力和信心。第二部分：技术综述聚合物薄膜的稳定性和可控去湿具有实际、技术和基础意义。从水溶液制备的聚合物薄膜的研究已经受到限制，由于在阐明干燥动力学和溶剂极性对薄膜稳定性的影响方面所涉及的特定挑战。在拟议的研究中，聚（乙烯醇）（PVOH）薄膜去湿硅晶片支撑的聚二甲基硅氧烷（PDMS）将使用一种新的制造方法，吸附旋转浇铸研究。该方法结合了PVOH在PDMS-溶液界面的自发吸附和通过定向干燥产生有序的PVOH去湿图案。选择PVOH是因为其可调的结晶度，这将允许研究一系列的去湿形态，从传统的液滴到具有独特分形特征的结构。硅晶片支撑的PDMS是选择的衬底，因为它将允许探测衬底迁移率和极性。该研究的新颖之处包括设计一种新的聚合物薄膜制造方法，以及系统地探索聚合物薄膜稳定性的相关但尚未探索的领域。作为历史最悠久的女子文理学院的教育家和女科学家，PI致力于提高妇女在STEM学科的代表性和保留率。她将招募和指导一群不同的本科女性，以开展本文提出的新的，相关的，可持续的和富有成效的研究。通过适当的结构、挑战和支持，学生将获得在STEM领域未来努力的能力和信心。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Adsorptive Spin Coating To Study Thin-Film Stability in Both Wetting and Nonwetting Regimes

吸附旋涂研究润湿和非润湿状态下的薄膜稳定性

• DOI: 10.1021/acs.langmuir.9b00923
• 发表时间: 2019
• 期刊: Langmuir
• 影响因子: 3.9
• 作者: Qi, Yueyue;Nguyen, Haimi;Lim, Kelly Sin;Wang, Wenyun;Chen, Wei
• 通讯作者: Chen, Wei

New Insights into Spin Coating of Polymer Thin Films in Both Wetting and Nonwetting Regimes

• DOI: 10.1021/acs.langmuir.2c02206
• 发表时间: 2022-10-06
• 期刊: LANGMUIR
• 影响因子: 3.9
• 作者: Jiang, Yuxin;Minett, Margaret;Chen, Wei
• 通讯作者: Chen, Wei