Artificial lung membranes are the heart for extracorporeal oxygenation. Hereinto, the nonporous PDMS-based membranes have excellent biocompatibility, and also isolation ability to both blood and harmful matters. Nevertheless, their CO 2 /O 2 selectivity, in the conventional cases using pure-oxygen sweeping stream, is not enough to accomplish sufficient CO 2 removal in balance with O 2 addition. In this work, the oxygenation mode using oxygen-enriched stream, faithfully based on the permeation mechanism, is established to overcome this bottleneck. To neutralize the negative impacts caused by lowering oxygen content and its partial pressure, PDMS-based composite membranes with ultra-thin selective layer to enhance mass transfer have been fabricated successfully. The experiments manifest that the selective layer, on the basic condition that the composite structure is stable enough to make surface modification and realistic utilization, is decreased to 376 nm on the porous substrates. O 2 and CO 2 permeation rates through the ultimate membrane samples have been enhanced to 502 GPU and 4117 GPU, respectively. In this instance, the essential oxygenation could be sustained with O 2 partial pressure less than 446 mmHg in the sweeping stream. The minimum membrane area for a common treatment case is 0.05 square meters. Once the membrane area is increased to 0.18 square meters, the sterile air after purification could be directly used for oxygenation. In comparison to the oxygenation devices being used currently, membrane area can be saved by about 90 %, which is highly significant to reduce the injuring influence on blood cells. All in all, the artificial lung membranes with ultra-thin PDMS coating layer have promising future in realistic utilization.
Zhao Sun,Hanpeng Liu,Hongcun Bai,Shufan Yu,Christopher K. Russell,Liang Zeng,Zhiqiang Sun
Reducing anthropogenic CO 2 emissions has become a primary environmental concern for the present society, making the development of energy-efficient, net-negative CO 2 emitting technology paramount. Here, the Chemical looping deoxygenated gasification (CLDG) process is experimentally conducted to demonstrate the crucial role of deoxygenation on syngas refinement and CO 2 utilization via Fe 0 ↔ Fe 3+ looping. A reduction of 0.324 g CO 2 per gram pine wood biomass gasified is achieved, a 288% reduction in CO 2 emissions compared with that of biomass conversion without deoxygenation. The superiority of CLDG can be also reflected in syngas yields increased by 16.37% and a CO 2 concentration decreased by 44.16%. Results from the heat balance calculation indicate that both the gasifier and the regenerator are endothermic, which cannot achieve the auto-thermal operation of CLDG, thus requires an extra energy supply source. Density functional theory calculations elucidate that the active site of CO 2 adsorption is located at the three-phase interface of CaO(1 1 1), Fe(1 1 0), and amorphous carbon (AC). It is anticipated that CLDG has the potential to serve as an effective measure for reducing CO 2 emissions while promoting syngas yield and quality.
危险品化学品经营许可证（带存储）