I-Corps: Formation of thin films with self-assembled monolayers embedded on their surfaces

I-Corps：形成表面嵌入自组装单分子层的薄膜

• 批准号: 1522607
• 负责人: Pushpendra Singh
• 金额: $ 5万
• 依托单位: New Jersey Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1522607&HistoricalAwards=false
• 关键词: Corps; Formation; thin; films; self

In many applications, thin films are coated onto the surface of materials to modify their mechanical, thermal, electrical, and optical properties. The coatings must be highly ordered two-dimensional crystals with a specific lattice spacing which is application dependent. For example, to make a highly-efficient anti-reflection coating for solar cells, the surface is textured with a periodic pattern with the wavelength comparable to that of solar radiation. This can be achieved by coating the surface by a thin film with a monolayer of particles embedded on its surface. The particle size and the spacing between particles can be selected for obtaining the desired pattern. These particle coated thin films can also be used for making masks for nano-lithography, textured hydrophobic surfaces, and membrane filters with regular pores. The membrane filters could be used to precisely control the mass transfer rate of a drug-delivery patch, and to separate proteins and other macromolecules based on their sizes. Capillarity-driven clustering at fluid interfaces is a well-established method for forming monolayers, but those monolayers are poorly ordered. In the proposed technique an electric field in the direction normal to the interface is applied to control the self-assembly process so to obtain a virtually defect-free monolayer of electrically neutral nano-particles. When there are two or more types of particles present, there is a hierarchical order in the assembled monolayers which can be optimized by selecting a suitable fluid. The technique also allows us to vary the lattice spacing as appropriate to the application. The monolayer is then frozen onto the surface of a thin flexible film which can be transferred to the surface of a material to modify its surface properties. The technique is easy to implement and can be applied to a broad range of particle sizes and types with a high level of controllability which will be advantageous in many applications.

在许多应用中，薄膜被涂覆到材料表面以改变其机械、热、电和光学特性。涂层必须是高度有序的二维晶体，​​具有取决于应用的特定晶格间距。例如，为了制造太阳能电池的高效减反射涂层，表面具有周期性图案的纹理，其波长与太阳辐射的波长相当。这可以通过在表面涂覆一层薄膜来实现，薄膜的表面嵌入有单层颗粒。可选择颗粒尺寸和颗粒之间的间距以获得所需的图案。这些颗粒涂层薄膜还可用于制作纳米光刻掩模、纹理疏水表面和具有规则孔的膜过滤器。膜过滤器可用于精确控制药物输送贴片的传质速率，并根据蛋白质和其他大分子的大小分离它们。流体界面处毛细管驱动的聚集是形成单层的成熟方法，但这些单层的有序性很差。在所提出的技术中，应用垂直于界面方向的电场来控制自组装过程，从而获得几乎无缺陷的电中性纳米颗粒单层。当存在两种或多种类型的颗粒时，组装的单层中存在分层顺序，可以通过选择合适的流体来优化该顺序。该技术还允许我们根据应用改变晶格间距。然后将单层冷冻到柔性薄膜的表面上，该薄膜可以转移到材料的表面以改变其表面特性。该技术易于实施，可应用于广泛的颗粒尺寸和类型，并且具有高度的可控性，这在许多应用中都是有利的。