One-step Co-deposition Method Research Articles

A bioactive tannic acid/vanadium ions co-deposited coating on various surfaces for antifouling, photothermal anti-bacterial, and antioxidant effects

Pathogenic bacteria attached to medical device surfaces result in the persistence of chronic bacterial infections and pose severe threats to human health. In this study, a one-step co-deposition method was developed to fabricate tannic acid (TA)-based vanadium ions (Vn+)-phenolic network coating. The successful co-deposition of PEG-TA/Vn+ on the Ti surfaces was confirmed by Scanning electronic microscopy (SEM), Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FITR), and X-ray photoelectron spectroscopy (XPS) analyses. The PEG-TA/Vn+ co-deposited coating showed excellent flexibility and good adhesion on various substrates. The as-prepared coating exhibited remarkable antifouling and photothermal antibacterial properties, preventing biofilm formation and scavenging the reactive oxygen species (ROS) during incubation with cells. The present work provides an efficient strategy for the design of antifouling, antibacterial, and antioxidant surface coating formulations to prevent medical device-associated infections.

Polyphenol zwitterionic nanohydrogel modified polyvinylidene difluoride membrane for separating oil-in-water emulsions with superior cycle stability

Numerous strategies have been proposed for the superwetting membranes application in the separation of oily wastewater. Here, benefiting from the hydrophilic properties of hydrogel and the adhesive properties of plant polyphenols, we proposed a polyphenol zwitterionic hydrogel coating Poly(DMA-co-SPP) to modify hydrophobic PVDF membranes by a one-step co-deposition method. The polyphenol zwitterionic nanohydrogel, Poly(DMA-co-SPP), were prepared by polymerization of ethanol-aqueous solution. The characterization of fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated the successful fabrication of the PVDF-Poly(DMA-co-SPP) membrane. The PVDF-Poly(DMA-co-SPP) membranes were designed with superhydrophilic/submerged superoleophobic surfaces, which exhibited excellent oil rejection rate (99%) and flux (2100 L·m−2·h−1·bar−1) for up to 30 separation cycles. The experimental results showed that the oil rejection rate (>99%) of iso-octane, dodecane and toluene emulsions was attributed to the low oil adhesion and hydration layer on the PVDF-Poly(DMA-co-SPP) membrane surface. The introduction of hydrogel particles improved the resistance of membranes to chemical and mechanical damage because of the interwoven hydrogen bonding and cross-linked network. This may stimulate advanced research into novel membrane materials for oily wastewater treatment.

Ceramic membrane with protein-resistant surface via dopamine/diglycolamine co-deposition

Protein separation and purification is important in biotechnology and food processing industries. Ceramic membranes have shown great potentials for this task. But membrane fouling remains a barrier to their widespread application due to the irreversible adsorption of protein onto the membrane. In this work, one-step co-deposition of dopamine (DA) and diglycolamine (DGA) was conducted on the ceramic membranes for fabricating protein-resistant surfaces. CuSO4/H2O2 was used as a trigger to shorten the deposition time and to improve the deposition efficiency. The effect of DA/DGA mass ratio on the membrane structures and properties was studied by FESEM, FTIR, XPS and contact angle measurements. The results indicate that the optimal DA/DGA mass ratio in the co-deposition solution is 1:4. The modified membranes show improved hydrophilicity and negatively charged property. In dynamic protein filtration, these ceramic membranes exhibit a higher permeate flux, a higher water flux recovery, and a lower water flux reduction compared to the original membrane. Moreover, the antifouling property of the modified membrane is preserved after the membranes are treated with high speed water scouring. As a result, this one-step co-deposition method is a simple and effective way to prepare durable fouling-resistant ceramic membranes for protein removal.