GOALI: Environmentally Benign Dry Particle Coating Processes for the Synthesis of Engineered Particulates

摘要CTS-9985618R。Pfeffer和R.Dave，NJITGOALI：用于合成工程颗粒的环保型干颗粒涂料工艺(可持续环境技术)干颗粒涂料可用于生产先进的粉末复合材料或具有定制表面特性的工程颗粒。除了在颗粒和其环境之间形成屏障外，干法颗粒涂层还可以用于改变原始主体颗粒的官能度或性质，从而产生具有更好的流动性、润湿性、分散性、电学、电磁、光学、热学和其他特定物理或化学特性的复合材料。在这个过程中，微小的、亚微米大小的(客体或细微的)颗粒被包裹在相对较大的微米大小的(主体或核心)颗粒上，以产生增值的复合颗粒材料。与需要有机溶剂、液体熔体或水溶液/悬浮液的湿粒子涂层不同，客体粒子通过施加机械力与主体粒子紧密接触，形成离散或连续的涂层。因此，这些工艺是环保的，不需要溶剂、粘结剂，甚至不需要水。然而，它们相对较新，仍处于开发的早期阶段，很少在商业上使用。然而，它们在许多行业都有潜在的应用，包括制药、食品、化妆品、陶瓷、电子和特种化学品。本提案旨在研究和开发这些干颗粒工艺，长期目标是使它们成为替代当前许多湿式涂料应用的可行选择，创造新的应用，并推进技术，以便为未来对颗粒涂料的预期高需求做好准备。建议研究NJIT提供的下列最先进的干法涂料设备：(1)磁力辅助撞击涂层(MAIC)，其中由磁性介质产生的强烈颗粒流态化和随机碰撞产生涂层；(2)机械熔融，即对粉末混合物施加高的正应力和剪应力以实现涂层。这些过程将通过实验和计算机模拟进行系统研究，以确定它们将在其下工作的条件(设备的操作参数以及颗粒的特性，包括尺寸、形状、机械和其他属性)以及它们可以实现的涂层类型(离散、连续、嵌入或薄膜类型)。计算机建模将基于离散元素模拟研究。预计将开发一种预测能力，这一能力目前还不存在，不仅需要确定哪种设备对特定应用的结果最好，而且还需要扩大和优化操作条件，以获得尽可能好的涂层颗粒。该项目的成功完成将对一些处理颗粒物的行业产生重大的科学和环境影响。通过与行业合作伙伴的合作，预计其中一些新应用将得到成功演示。此外，预计系统的研究将推动这一领域的更多工作，最终在工业上用干法涂料工艺取代许多湿法涂料工艺将有助于从源头上防止污染。这项提议的次要目标包括对本科生和研究生进行粒子技术方面的培训，这是工程技术教育中一个相对被忽视的领域，具有极其重要的技术、经济和环境意义。这将通过将研究结果纳入NJIT新开发的粒子技术跨学科三门课程集中来实现。

AbstractCTS-9985618R. Pfeffer and R. Dave, NJITGOALI: Environmentally Benign Dry Particle Coating Processes for the Synthesis of Engineered Particulates (Technology for a Sustainable Environment)Dry particle coating can be used to produce advanced powder composites or engineeredparticulates with tailored surface properties. In addition to forming a barrier between the particle and itsenvironment, dry particle coating can be used for changing the functionality or the properties of theoriginal host particles producing composites that show improved flowability, wettability, dispersibility,electrical, electro-magnetic, optical, thermal and other specific physical or chemical properties. In thisprocess, tiny, sub-micron sized (guest or fine) particles are coated onto relatively larger, micron sized(host or core) particles in order to create value-added composite particulate materials. In contrast to wetparticle coating, which requires organic solvents, liquid melts, or aqueous solutions/suspensions, the guestparticles are brought into close contact with the host particles through the application of mechanicalforces, creating either discrete or continuos coatings. Hence these processes are environmentally friendly,requiring no solvents, binders or even water. However they are relatively new, are still in the early stageof development and are rarely used commercially. Yet they have potential applications in many industriesincluding pharmaceuticals, food, cosmetics, ceramics, electronics and specialty chemicals. This proposalis aimed at research and development of these dry particulate processes with the long-term goal of makingthem a viable option for replacing many current wet coating applications, creating new applications, andadvancing the technology so as to be ready for the anticipated high demand for particle coatings in thefuture.It is proposed to investigate the following state-of-the-art dry coating devices available at NJIT: (1)Magnetically Assisted Impaction Coating (MAIC), in which intense particle fluidization and randomcollisions created by magnetic media produce coatings; (2) Mechanofusion, in which high normal and shear stresses are applied to the powder mix to achieve coating. These processes will be systematically studied both experimentally and by computer modeling, so as to determine the conditions (operatingparameters of the devices as well as the characteristics of the particles, including size, shape, andmechanical and other properties) under which they will work, and the type of coatings (discrete,continuous, embedded or film type) they can achieve. Computer modeling will be based on discreteelement simulation studies. It is expected to develop a predictive capability, which is currently non-existent, and is necessary not only to determine which of the devices would give the best results for a specific application, but also to scale-up and optimize the operating conditions for obtaining the best possible coated particles.Successful completion of this project will have a major scientific and environmental impact on anumber of industries that deal with particulates. Through collaboration with industrial partners, it is expected that some of these new applications will be successfully demonstrated. Furthermore, it is expected that systematic research study will serve as an impetus for more work in this area andthe eventual replacement of many wet coating processes by dry coating processes in industry willhelp to prevent pollution at the source. A secondary objective of this proposal involves training of undergraduate and graduate students in particle technology, a relatively neglected area in engineeringeducation of extreme technological, economic and environmental importance. This will be carried out byincorporating the results of research into the newly developed interdisciplinary three-course concentration in particle technology at NJIT.