High performance countercurrent membrane purification (HPCMP) has emerged as a promising diffusive separation strategy for the purification of recombinant proteins and monoclonal antibodies (mAbs). However, prior studies employed dialysis membranes, which are designed for diffusive separations but have not been validated for biopharmaceutical manufacturing. This study evaluates the ability of commercial ultrafiltration (UF) membranes, engineered for pressure-driven filtration, to support highly selective diffusive separations. Scanning electron microscopy (SEM) analysis of the membrane cross-sections revealed marked morphological differences between UF and dialysis membranes. Yet, transport studies using polydisperse dextrans and model proteins demonstrated that UF membranes can deliver exceptional diffusive separation selectivity. In particular, a 100 kDa polysulfone membrane (Cytiva) provided >150-fold diffusive selectivity between bovine serum albumin (BSA) and immunoglobulin G (IgG). When utilized for mAb separation from a clarified CHO cell culture fluid, this membrane achieved >98% product yield, near-complete removal of low molecular weight species, and significant reduction in both DNA and host cell protein (HCP) levels. These results demonstrate that commercial UF membranes that are validated for bioprocessing applications can be repurposed for HPCMP, enabling scalable, continuous downstream processing of biotherapeutics.

CO2 injection into subsurface reservoirs is an effective method for CO2 storage and higher geological resources recovery in low-permeability reservoirs. However, substantial CO2 coproduction during conventional CO2 flooding limits storage efficiency. In this study, a natural amphiphilic molecule (ARGS) is introduced to enhance oil recovery and CO2 storage by regulating CO2-oil-water-rock interfacial and mass-transfer properties under saline conditions, achieving a 9.7% increase in oil recovery compared with conventional CO2-enhanced oil recovery (CO2-EOR) and a CO2 storage ratio of up to 85% simultaneously. Under high-salinity formation-water conditions, ARGS increased CO2 solubility by 4-fold and reduced the interfacial tension of the CO2-formation water system by 36%. At the water-rock interface, ARGS shifted pore-surface wettability from neutral-wet to water-wet. During ARGS-assisted CO2 injection, oil displacement efficiency in micro- and mesopores increased by 10%-15%, expanding the CO2 sweep range and providing more pore space for CO2 storage. By enhancing the water-wetness of pore walls, ARGS increased CO2 flow resistance and consequently promoted both dissolved and trapped CO2 storage. Ultimately, the proportion of dissolved CO2 can reach 70%. This study provides an environmentally friendly approach for the efficient CO2 geological storage and utilization in low-permeability reservoirs.