Water-Resistant Photo-Crosslinked PEO/PEGDA Electrospun Nanofibers for Application in Catalysis

Abstract

Catalysts are used for producing the vast majority of chemical products. Usually, catalytic membranes are inorganic. However, when dealing with reactions conducted at low temperatures, such as in the production of fine chemicals, polymeric catalytic membranes are preferred due to a more competitive cost and easier tunability compared to inorganic ones. In the present work, nanofibrous mats made of poly(ethylene oxide), PEO, and poly(ethylene glycol) diacrylate, PEGDA, blends with the Au/Pd catalyst are proposed as catalytic membranes for water phase and low-temperature reactions. While PEO is a water-soluble polymer, its blending with PEGDA can be exploited to make the overall PEO/PEGDA blend nanofibers water-resistant upon photo-crosslinking. Thus, after the optimization of the blend solution (PEO molecular weight, PEO/PEGDA ratio, photoinitiator amount), electrospinning process, and UV irradiation time, the resulting nanofibrous mat is able to maintain the nanostructure in water. The addition of the Au6/Pd1 catalyst (supported on TiO2) in the PEO/PEGDA blend allows the production of a catalytic nanofibrous membrane. The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), taken as a water phase model reaction, demonstrates the potential usage of PEO-based membranes in catalysis.

Under-Oil Superhydrophilic/Superhydrophobic Janus Nanofibrous Membrane for Highly Efficient Separation of Surfactant-Stabilized Water-in-Oil Emulsions

“…When the mass ratio of PVDF-HFP to PEGDA was below 100:150, however, several beads appeared and were traversed by nonuniform fibers (Figures d and e). This is due to the fact that the molecular weight of PEGDA is relatively low, and when the content of PEGDA is high, the viscosity of the mixed solution is too low to produce well-formed nanofibers during the electrospinning process …”

“…This is due to the fact that the molecular weight of PEGDA is relatively low, and when the content of PEGDA is high, the viscosity of the mixed solution is too low to produce well-formed nanofibers during the electrospinning process. 33 The chemical structure of PHP electrospun membranes was analyzed by recording the FTIR spectra. As shown in Figure 2f, compared to pure PH membrane, the spectra of PHNP (i.e., without UV irradiation) and PHP both exhibited peaks at 1099 cm −1 , 1717 cm −1 , 2873 cm −1 , and 1640 cm −1 , which should be assigned to the stretching vibration of −C−O−C, −O−C�O, −CH, and −C�C−, 34 thus indicating that the PEGDAmodified PVDF-HFP nanofibers were successfully prepared.…”