Atomically Precise Membranes for the Separation of Hydrocarbons

Separations often account for a majority of process costs. This is because all traditional separation processes have inherent weaknesses that prevent the system from achieving perfect (or even near perfect in many instances) selectivity. These weaknesses result in large recycle streams and require multiple separation units in concert in order to produce a product clean enough for use or sale. An atomically-precise membrane capable of allowing passage to only certain molecules would greatly improve process economics. We propose to develop atomically precise, triangular and square pore-containing macromolecules using a unique, stiff, programmable molecular scaffold developed in Prof. Schafmeister’s lab. We will synthesize porous triangular and square macromolecules from our unique, poly-cyclic, shape-programmable and functional group-programmable spiroligomer scaffolds. We will synthesize stiff molecular segments that vary from 1 to 2 nanometers in length and link them end-to-end incorporating three of them together to form triangles and four of them to form squares. We will incorporate these pore containing macromolecules into atomically precise membranes that display the ultimate density of pores and extremely high flux and selectivity. The pores will be of programmable size and shape to selectively allow some molecules and ions to pass through the pores while resisting others. Systems like this could replace fractional distillation in the petroleum industry and myriad purification systems in the chemical processing and pharmaceutical industries with inexpensive, ultra-low-energy consumption, atomically precise membrane systems. In Phase I, sheets of atomically precise cross-linked macromolecules will be synthesized and characterized. In Phase II, we will transition these macromolecular sheets to a robust, scalable membrane capable of selective separations. The commercial applications of these membranes are immense and include pharmaceuticals, hydrocarbons, and the food industry. The public will benefit from lower cost goods as a result of more efficient manufacturing processes. The public will also benefit from the reduced emissions of processes made more efficient by these membranes.