Recently, the research team of professor Wei Guo and the team of professor Sui Zhao from Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, reported how to improve the zwitterionic membrane property from molecular dynamics simulation to structure manipulation, which provides a new perspective on the design of high-performance functional materials. This work has recently been published in the journal ACS Applied Materials & Interfaces (IF=9.229) with the title “Antibiotic zwitterionic nanogel membrane: from molecular dynamics simulation to structure manipulation”.

Membrane separation has been considered as one of the most revolutionary technologies for the removal of oils, dyes, or other pollutants from wastewater. However, most membranes still face great challenges in water permeability, antifouling property, and even antibiotic ability. Possessing a pathogen-repellent surface is of great significance as it can enable membranes to minimize the presence of active viral pathogens. Herein, we demonstrate a distinct design with a molecular dynamic simulation-guided experiment for the surface domination of antibiotic zwitterionic nanogel membranes. The zwitterionic nanoparticle gel (ZNG)/Cu2+/glutaraldehyde (GA) synergy system is first simulated by introducing a ZNG into a preset CuCl2 brine solution and into a GA ethanol solution, in which the nanogel is observed to initially swell and subsequently shrink with the increase of GA concentration, leading to the membrane surface structure transition. Then, the corresponding experiments are performed under strict conditions, and the results suggest the surface structure transition from nanoparticles to network nanoflowers, which are consistent with the simulated results. The obtained network structure membrane with super hydrophilic and underwater super oleophobic abilities can significantly enhance the water permeability as high as almost 40% with its original rejection rate in comparison with unoptimizable ZNG-PVDF (polyvinylidene difluoride) membranes. Moreover, the obtained membrane achieves additional excellent antibiofouling capacity with the antibiotic efficiency exceeding 99.3%, manifesting remarkable potential for disinfection applications. By comparison, the conventional antibiotic methods generally improve the membrane’s antibiotic property solely but can hardly improve the other properties of the membrane. That is to say, our simulation combined with the experimental strategy significantly improved the zwitterionic membrane property in this work, which provides a new perspective on the design of high-performance functional materials.

PhD student Qin Jiang from Technical Institute of Physics and Chemistry of CAS and professor Wei Guo from Institute of Food Science and Technology, CAAS as the co-first author. Professor Zi-Yu Liu, Jun-Bing Fan, and Sui Zhao as corresponding authors. The authors thank the financial support from the National Science Foundation of China (22075304 and 21872158), National Key R&D Program of China (2017YFC1600903), and the Important National Science and Technology Specific Project of China (2017ZX05013-003).

Figure 1. MD simulation dominated the fabrication of structured zwitterionic-nanogel membrane. (a) Chemical structures of zwitterions (DMAPS), PDA and GA molecules. (b) MD simulation guidelines of zwitterionic-nanogel membrane optimization design by introducing ZNG into presetted CuCl2 brine solution and GA ethanol solution, respectively, to investigate ZNG deformation. (c) Preparation of the structured zwitterionic-nanogel membrane based on MD simulation. At secondary GA treatment with 1.8−2.3 wt % concentration, the ZNG on the membrane surface translates from the nanoparticle to network nanoflower which leads to a large flux. The colors are as follows: green is for the zwitterions (DMAPS); yellow is for GA; and blue is for Cu2+ ions, respectively.

Link to the paper: https://pubs.acs.org/doi/10.1021/acsami.1c00378