Artificial
lung (AL) membranes are used for blood oxygenation for
patients undergoing open-heart surgery or acute lung failures. Current
AL technology employs polypropylene and polymethylpentene membranes.
Although effective, these membranes suffer from low biocompatibility,
leading to undesired blood coagulation and hemolysis over a long term.
In this work, we propose a new generation of AL membranes based on
amphiphobic fluoropolymers. We employed poly(vinylidene-co-hexafluoropropylene), or PVDF-co-HFP, to fabricate
macrovoid-free membranes with an optimal pore size range of 30–50
nm. The phase inversion behavior of PVDF-co-HFP was
investigated in detail for structural optimization. To improve the
wetting stability of the membranes, the fabricated membranes were
coated using Hyflon AD60X, a type of fluoropolymer with an extremely
low surface energy. Hyflon-coated materials displayed very low protein
adsorption and a high contact angle for both water and blood. In the
hydrophobic spectrum, the data showed an inverse relationship between
the surface free energy and protein adsorption, suggesting an appropriate
direction with respect to biocompatibility for AL research. The blood
oxygenation performance was assessed using animal sheep blood, and
the fabricated fluoropolymer membranes showed competitive performance
to that of commercial polyolefin membranes without any detectable
hemolysis. The data also confirmed that the bottleneck in the blood
oxygenation performance was not the membrane permeance but rather
the rate of mass transfer in the blood phase, highlighting the importance
of efficient module design.
Power
plants consume a major fraction of water to generate electricity,
typically in the range between 30–50% of all fresh water sources.
Most of the water from plants are lost with heat through stack and
cooling towers. It has been reported that if 20% of this water can
be recycled, power plants can be self-sustainable, allowing them to
be located with higher flexibility. Membrane contactor process can
be an effective solution to harness this source of water, but most
of the studies have been focused on dense vapor separation membranes
with limited success. In this work, we investigated a potential application
of membrane condenser technology to harness fresh water from power
plants. It has been shown that the membrane condenser configuration
can be 3 orders of magnitude more effective in recovering water compared
to dense vapor separation membranes, with a reasonable water/SO
x
selectivity of 100. We have prepared suitable
ceramic membranes as a proof-of-concept and achieved up to 85% dehumidification
efficiency in a single-pass flow. A thorough energy balance indicates
that both heat and water flux must be carefully balanced to maximize
the membrane condenser performance, and an effective module design
must be developed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.