UNS:New strategies for ultra-thin sub-10 nm thick zeolitic imidazolate framework membranes with tunable molecular sieving properties

Jeong151530Texas Engineering Exp Stap将需要的化学品与不需要的化学品分开，这对化工和石化行业至关重要。传统的分离技术，包括蒸馏和冷凝，都是高度耗能的。由于最先进的膜材料的限制，目前还没有商业上可用的膜来分离工业上重要的碳氢化合物气体。新型分子筛(即具有明确分子尺度的孔和通道的材料)已被探索作为膜材料。这项拟议的工作旨在开发创新的新方法，1)通过使分子筛膜非常有效来降低膜的成本，2)使筛子尺寸易于调节，以分离感兴趣的气体混合物。这里提出的全新策略预计将导致一系列分子筛分材料，其筛分尺寸经过精细调整，可用于工业上感兴趣的气体混合物的定制分离。这项工作的目标是开发新的方法来制备超薄、亚10纳米厚的沸石咪唑骨架(ZIF)膜，并不断调整其分子筛分性能以分离感兴趣的气体混合物。分子筛咪唑骨架(ZIF)是金属有机骨架(MOF)的一个子类，主要由于其超微孔(孔小于5？)和不同寻常的热/化学稳定性而在气体分离中提供独特的机会。为了解决上述基本材料限制和加工挑战，PI建议开发新的策略，使1)合成超薄ZIF膜和2)控制其分子筛分性能，以定制分离感兴趣的气体混合物。拟议的策略将真正具有变革性，因为它们能够制备高效和多产的分子筛膜，有可能取代高度能源密集型的电流分离过程，从而显著降低能源消耗。参与该项目的学生将接受从材料合成/表征到膜科学和技术的多学科领域的培训。

Jeong151530Texas Engineering Exp StaSeparations of desired chemicals from undesired ones are critically important for chemical and petrochemical industries. Conventional separation technologies, including distillation and condensation, are highly energy intensive. Due to the limitations of the state-of-the-art membrane materials, there are no commercially available membranes for the separation of industrially important hydrocarbon gases. Novel molecular sieves (i.e., materials with well-defined molecular-scale pores and channels) have been explored as membrane materials. The proposed work intends to develop innovative new approaches 1) to reduce the cost of membranes by making molecular sieving membranes very efficient and 2) to make the sieve size readily adjustable for the separation of gas mixtures of interest. The completely new strategies proposed here are expected to lead to a serious of molecular sieving materials with their sieve sizes finely-tuned for the custom separations of gas mixtures of industrial interest. The goal of the proposed effort is to develop new approaches to fabricate ultra-thin sub-10 nanometer thick zeolitic imidazolate framework (ZIF) membranes as well as to continuously tailor their molecular sieving properties for the separations of gas mixtures of interest. Zeolitic imidazolate frameworks (ZIFs), a sub-class of metal-organic frameworks (MOFs), offer unique opportunities in gas separations primarily due to their ultra-micropores (pores smaller than 5 Å) and their unusual thermal/chemical stabilities. To address the fundamental materials limitations as well as the processing challenges mentioned above, the PI proposes to develop new strategies that enable 1) the synthesis of ultra-thin ZIF membranes and 2) the control of their molecular sieving properties for the custom separations of gas mixtures of interest. The proposed strategies will be truly transformative in that they enable the preparation of highly efficient and productive molecular sieving membranes, potentially replacing highly energy-intensive current separation processes, thereby significantly reducing energy consumption. The students involved in this project will be trained in multi-disciplinary areas ranging from material synthesis/characterization to membrane science and technologies.