In this study, polyamide (PA) thin-film composite (TFC) nanofiltration membranes were fabricated via interfacial polymerization on cellulose acetate (CA)/poly(vinylidene fluoride) (PVDF) support layers. Several types of CA/PVDF supports were prepared via the phase inversion method. With increasing CA, the PVDF membrane surface pore size decreased and hydrophilicity increased. The effect of the support properties on the performance and formation mechanism of PA films was systematically investigated via an interfacial polymerization (IP) process. The permselectivity of the resulting TFC membranes was evaluated using a MgSO4 solution. The results show that the desired polyamide TFC membrane exhibited excellent water flux (6.56 L/(m2·h·bar)) and bivalent salt ion rejection (>97%). One aim of this study is to explore how the support of CA/PVDF influences the IP process and the performance of PA film.

The anti-icing property of materials can be influenced by many factors, such as mechanical forces, electrostatic forces, van der Waals interaction and so on. In this research, the effect of thermal conductivity on the anti-icing performance of coated fabrics was studied. An instrument to observe the melting process of the ice on various materials was designed, by which the melting rate of the ice on the samples could be tested. A formula for the variation of the melting rate of the ice on the samples against the thermal conductivity of the samples was deduced using a mathematical method. It was proved that the formula can be used to study the effect of thermal conductivity on the anti-icing performance of coated fabrics. A coated fabric with anti-icing performance was prepared with Nomex IIIA fabrics, PU-2540 (Polyurethane-2540), Teflon emulsion, graphite powder, SiC powder and TG-581 (fluorine-containing water and oil repellent-581) using a knife coating method. The properties of the samples were investigated by using a video optical contact angle measuring instrument (OCA15 Pro), a thermal constants analyzer (TPS2500S, Hot Disk, Sweden), an anti-icing property tester, and other devices. Results show that the coated fabrics prepared in this manner have good performance in ease of ice removal and a low interaction with water and ice, resulting in good anti-icing properties.

The anti-icing properties of fabrics can be considered as involving two parts, the super-hydrophobic property and the ease of ice removal property. In this study, a super-hydrophobic surface was built on to the outer layer of firefighter clothing using nano-silica, C13H13F17O3Si, C19H42O3Si and PU-2540 using a coating method. This coating stops water drops from staying on the fabric surface easily. At the same time, an ultra-smooth surface was built on to the super-hydrophobic surface already created on the fabric using perfluoropolyethers (PFPE) oil by a dipping method, which adds an ice removal function to the fabrics. The anti-icing properties of the samples prepared in the research described in this paper have been investigated using field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), ease of ice removal property tests and static water contact angle analysis. At the same time, the thermal protective performance (TPP) of the samples, before and after super-hydrophobic treatment, was studied by a TPP tester. Results show that the super-hydrophobic coating with an ultra-smooth surface can significantly increase the anti-icing properties of the fabrics used for the outer layer of firefighter clothing. C13H13F17O3Si and C19H42O3Si can improve the hydrophobic properties of the coating. The anti-icing coating in this paper can increase the TPP of the fabrics.

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The ease of ice removal (EIR) property indicates how easy it will be to remove ice from materials. In this study, an EIR coating was built on to the outer layer of firefighter clothing using polyurethane-2540, Teflon emulsion, nano-silica powder, copper powder and fluorine-containing water and oil-repellent-581 using a knife coating method. This coating adds an EIR function to the fabrics. The properties of the samples prepared in this paper were investigated using field emission scanning electron microscopy, a video optical contact angle measuring instrument (OCA15), an impedance analyzer (KEYSIGHT E4991B) and an EIR property tester. At the same time, the thermal protective performance (TPP) of the samples, before and after coating treatment, was studied using a TPP tester. The results show that the EIR coating can significantly increase the EIR property of the fabrics used for the outer layer of firefighter clothing. Mechanical forces between the material and ice have obvious influence on the freezing adhesive strength. Materials with lower permittivity have lower freezing adhesive strength. The EIR coating described in this paper can increase the TPP of the fabrics.