Vascular cell behavior on material surfaces, such as heparin-like polymers, can be affected by the surface chemical composition and surface topological structure. In this study, the effects of heparin-like polymers and lotus leaf-like topography on surface vascular cell behavior are considered. By combining multicomponent thermo-curing and replica molding, a polydimethylsiloxane surface containing bromine (PDMS-Br) with lotus leaf-like topography is obtained. Heparin-like polymers with different chemical compositions are grafted onto PDMS-Br surfaces using visible-light-induced graft polymerization. Compared with unmodified PDMS-Br, surfaces modified by sulfonate-containing polymers are more friendly to vascular cells, while those modified by a glyco-polymer are much more resistant to vascular cells. The introduction of lotus leaf-like topography results in different degrees of decrease in cell density on different heparin-like polymer-modified surfaces. In addition, the combination of heparin-like polymers and lotus leaf-like topography results in the change in protein adsorption, indicating that the two factors may affect the surface vascular cell behavior by affecting the adsorption of relative proteins. The combination of bionic surface topography and different chemical components of heparin-like polymers on material surfaces suggests a new way of engineering cell-material interactions.
Oil and organic pollutants removal becomes an efficient solution to dispose of industrial oily and textile dye wastewater. This study proposes a lotus leaf-like bionic nanofibrous membrane with underwater superoleophobic for highly efficient oil-water separation. Papillary structure of the bionic membrane is formed by electrospraying of PVDF and TiO 2 solutions on the surface of beaded-structure PVDF/TiO 2 membrane. Dopamine is then decorated on the resultant PVDF/TiO 2 membrane by in situ polymerization to be with hydrophilic-underwater oleophobic property for highly efficient oil-water separation. This bionic membrane has > 99 % oil-water separation efficiency, and high flux of 1389 ± 67 L m −2 h −1 . Its contact angle of underwater petroleum ether and dichlomethane reaches 155° and 152°, respectively. Moreover, it has excellent water transport capacity, photocatalytic property, as well as high separation efficiency and flux even after 5-cycle filtration. This bionic nanofibrous membrane will become a promising candidate in clean production, industrial oil/water separation, water purification and efficient liquid transmission.
Yi Li,Xianfeng Chen,Bihe Yuan,Qi Zhao,Chuyuan Huang,Lijuan Liu
A novel inhibitor of PA-MEL@NH 2 -Al 2 O 3 was synthesized by using supramolecular self-assembly technique with phytic acid (PA) and melamine (MEL) as the building blocks. Bauxite is a kind of mining waste, which is abundant in Al 2 O 3 and is used as loading matrix. By right of lotus leaf-like structure, the hygroscopicity of PA-MEL@NH 2 -Al 2 O 3 is greatly weakened. The feasibility of inhibiting CH 4 /H 2 /air explosion by different concentrations of PA-MEL@NH 2 -Al 2 O 3 was explored in a 20 L Spherical explosive vessel. The optimum inhibitory effect is obtained when the concentration is 0.25 g/L. The maximum pressure ( P max ) and maximum pressure rise rate ( (dP/dt) max ) decrease by 52.41 % and 83.50 % respectively. The induction time and the time to maximum pressure are prolonged to 193 and 400 ms, respectively. The synergistic inhibition mechanism of physics and chemistry is illustrated in the analysis of post-explosion residues. This work provides an efficient and promising approach for the suppression of CH 4 /H 2 /air explosion by synthesizing the prolonged action inhibitor with a lotus leaf-like structure.