Aligned porous Chitosan/Ti3C2 MXenes monolith as a high-performance fixed-bed separation medium toward globular albumin separation

Abstract

Designing and tuning macropores into aligned structure is of considerable importance in promoting mass transfer, improving chromatographic performance and enhancing column efficiency. Herein, we have synthesized an innovative aligned porous Chitosan/Ti3C2 MXenes monolith via a facile, versatile and reproducible unidirectional “freeze-casting” method. Typically, the accumulation of Ti3C2 MXenes directs the formation of aligned structure during the unidirectional freezing process and thus aligned macropores are formed by a subsequent freeze-drying process. By various physical characterization, the distribution of aligned macropores, micropores and specific surface area are determined to be 21 μm, 2.53 nm and 103.09 m2·g−1, respectively. In addition, monolith bed permeability is calculated to be 1.94 × 10-12 m2, approximately 10 times than conventional monolith. Batch adsorptive experiments confirm that adsorptive capacities to bovine serum albumin and bovine hemoglobin are remarkably elevated on account of the high affinity of proteins onto those imbedding Ti3C2 MXenes. Meanwhile, continuous mass transfer equation describes the aligned macropores facilitate the film mass transfer factor ([kLa]f) in a separation process thus driving the global mass transfer factor ([kLa]g). It is expected that the aligned porous Chitosan/Ti3C2 MXenes monolith promises great potential for a continuous separation of proteins when a wholesale production is required.