Anti-biofouling shape-memory composite aerogel and preparation method

#This application claims priority to Chinese Patent Application No. 202210363657.9 with a filing date of Apr. 7, 2022. The content of the application mentioned above, including any intervening amendments thereto, is incorporated herein by reference.

#The present disclosure relates to the technical field of nanomaterials, in particular to an anti-biofouling shape-memory composite aerogel and a preparation method and use thereof.

#Interfacial solar evaporation is a new technology that offers an opportunity to produce clean water in a sustainable, eco-friendly and energy-efficient manner. This technology converts solar energy into thermal energy through photothermal conversion materials at a water-air interface, thereby accelerating water evaporation to separate water and pollutants. At present, porous photothermal materials can promote light absorption and steam release, weaken the salt resistance effect, and are widely used in solar evaporation. However, a large number of microorganisms in the real water environment can adhere to the inner and outer surfaces of porous materials and further proliferate to form biofilms. As a result, the formation of biofouling clogs the water and vapor transport channels, and eventually leads to a decrease in photothermal conversion and water evaporation. In nature, besides bacteria, fungal infestation can also contaminate the materials. Therefore, it is necessary to develop effective and convenient broad-spectrum antimicrobial and anti-biofouling designs for porous photothermal materials. In addition, to achieve stable use for a long time, photothermal water evaporation materials also need to have a desirable structural stability.

#FIG. 1 shows a scanning electron microscopy (SEM) photo of transverse and longitudinal sections of a chitosan aerogel;

#FIG. 2 shows that a chitosan-TA aerogel (a) and natural oak (b) are directly placed in a Fe3+ solution for 12 h, and shows a real photo (c) after the chitosan-TA aerogel undergoes 6 compression-release cycles in the Fe3+ solution;

#FIG. 3 shows a real photo and a SEM image of transverse and longitudinal sections of a chitosan-TA-iron composite aerogel;

#The above and other technical features and advantages of the present disclosure will be described below in more details in connection with the accompanying drawings.

#In this example, a method for preparing a biomimetic chitosan aerogel (CS aerogel) includes the following steps: (1) 2 g of a chitosan powder was evenly mixed into 99 mL of deionized water and 1 mL of acetic acid, and then stirred overnight to obtain a 2% chitosan solution; (2) the chitosan solution was oriented-frozen with liquid nitrogen for 30 min, and then freeze-dried for 48 h to obtain an original chitosan aerogel; and (3) the original chitosan aerogel was immersed for washing in a methanol solution containing sodium hydroxide and a tert-butanol solution in sequence, frozen with liquid nitrogen, and then freeze-dried to obtain the biomimetic chitosan aerogel.

#FIG. 1 showed a SEM image and a real image of transverse and longitudinal sections of the chitosan aerogel in this example. It was found that the chitosan aerogel had an oriented channel in the longitudinal direction and a honeycomb porous structure in the transverse direction, and had a pore size of 20 μm to 200 μm.