Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phosgene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic ca...Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phosgene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic carbonate)precursors bearing multiple carbonate moieties(multi-5CCs)is a key requisite for preparing PHUs by polyaddition reaction with bis-or polyamines.Producing sustainable PHUs from CO_(2)-based five-membered cyclic carbonates(5CCs)obtained from biobased epoxides is a valuable strategy to bridge CO_(2) utilization and the upcycling of renewable substrates.In this context,while many multi-5CC monomers reported in the literature are oil-based,recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO_(2) and renewable resources such as fatty acids and vegetable oils,lignin,terpenes,and sugars.In this work,recent crucial advances(2019—2023)on PHUs prepared from bis-and multi-5CCs produced from CO_(2) and(partially/potentially)biobased substrates are reviewed with respect to their synthesis,thermal and mechanical properties,and their recent,emerging applications.展开更多
Reusable face masks are an important alternative for minimizing costs of disposable and surgical face masks during pan-demics.Often complementary to washing,a prolonged lifetime of face masks relies on the incorporati...Reusable face masks are an important alternative for minimizing costs of disposable and surgical face masks during pan-demics.Often complementary to washing,a prolonged lifetime of face masks relies on the incorporation of self-cleaning materials.The development of self-cleaning face mask materials requires the presence of a durable catalyst to deactivate contaminants and microbes after long-term use without reducing filtration efficiency.Herein,we generate self-cleaning fibers by functionalizing silicone-based(polydimethylsiloxane,PDMS)fibrous membranes with a photocatalyst.Coaxial electro-spinning is performed to fabricate fibers with a non-crosslinked silicone core within a supporting shell scaffold,followed by thermal crosslinking and removal of the water-soluble shell.Photocatalytic zinc oxide nanoparticles(ZnO NPs)are immo-bilized on the PDMS fibers by colloid-electrospinning or post-functionalization procedures.The fibers functionalized with ZnO NPs can degrade a photo-sensitive dye and display antibacterial properties against Gram-positive and Gram-negative bacteria(Escherichia coli and Staphylococcus aureus)due to the generation of reactive oxygen species upon irradiation with UV light.Furthermore,a single layer of functionalized fibrous membrane shows an air permeability in the range of 80-180 L/m^(2)s and 65%filtration efficiency against fine particulate matter with a diameter less than 1.0µm(PM_(1.0)).展开更多
基金the National Research Council of Thailand(grants N41A640170 and N42A650196)for research supportD.C.acknowledges funding support from the NSRF(National Science,Research and Innovation Fund)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(grant number B05F640208).
文摘Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phosgene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic carbonate)precursors bearing multiple carbonate moieties(multi-5CCs)is a key requisite for preparing PHUs by polyaddition reaction with bis-or polyamines.Producing sustainable PHUs from CO_(2)-based five-membered cyclic carbonates(5CCs)obtained from biobased epoxides is a valuable strategy to bridge CO_(2) utilization and the upcycling of renewable substrates.In this context,while many multi-5CC monomers reported in the literature are oil-based,recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO_(2) and renewable resources such as fatty acids and vegetable oils,lignin,terpenes,and sugars.In this work,recent crucial advances(2019—2023)on PHUs prepared from bis-and multi-5CCs produced from CO_(2) and(partially/potentially)biobased substrates are reviewed with respect to their synthesis,thermal and mechanical properties,and their recent,emerging applications.
基金Funding Open Access funding provided by Lib4RI-Library for the Research Institutes within the ETH Domain:Eawag,Empa,PSI&WSL.
文摘Reusable face masks are an important alternative for minimizing costs of disposable and surgical face masks during pan-demics.Often complementary to washing,a prolonged lifetime of face masks relies on the incorporation of self-cleaning materials.The development of self-cleaning face mask materials requires the presence of a durable catalyst to deactivate contaminants and microbes after long-term use without reducing filtration efficiency.Herein,we generate self-cleaning fibers by functionalizing silicone-based(polydimethylsiloxane,PDMS)fibrous membranes with a photocatalyst.Coaxial electro-spinning is performed to fabricate fibers with a non-crosslinked silicone core within a supporting shell scaffold,followed by thermal crosslinking and removal of the water-soluble shell.Photocatalytic zinc oxide nanoparticles(ZnO NPs)are immo-bilized on the PDMS fibers by colloid-electrospinning or post-functionalization procedures.The fibers functionalized with ZnO NPs can degrade a photo-sensitive dye and display antibacterial properties against Gram-positive and Gram-negative bacteria(Escherichia coli and Staphylococcus aureus)due to the generation of reactive oxygen species upon irradiation with UV light.Furthermore,a single layer of functionalized fibrous membrane shows an air permeability in the range of 80-180 L/m^(2)s and 65%filtration efficiency against fine particulate matter with a diameter less than 1.0µm(PM_(1.0)).
