Self-cleaning fabrics decorated with titanium dioxide (TiO2) nanoparticles (NPs) have garnered worldwide attention due to their outstanding ultraviolet (UV) light-shielding, anti-bacterial properties and other characteristics. Numerous techniques to construct super-antiwetting surfaces have been investigated for both fundamental research and practical application. A facile and eco-friendly way by a combination of UV irradiation and ultrasonic bath method has been developed to prepare a novel self-cleaning hybrid polyamine 6/nano TiO2 (PA6/nano TiO2) fabric with superhydrophobic and durable photocatalytic properties. To evaluate the fabric's reusability, hybrid PA6/nano TiO2 fabrics were subjected to five consecutive cycles of the photocatalytic degradation of the methyl orange (MO) dye. The results indicated that TiO2 NPs were firmly fixed on the fiber surface. The UV-blocking and anti-microbial properties of these hybrid fabrics were also tested. For PA6 immobilized by commercial nano TiO2-P25 (P25-PA6) and PA6 immobilized by prepared visible-light photocatalyst PVAD-TiO2(PVAD-PA6) fabrics, the UV protection factors (UPFs) of the samples were 56 and 1123, respectively. The anti-microbial efficacies of the two samples were both 99%. The water contact angles were 151.7° and 154.6°, respectively, indicating surface superhydrophobicity. These results showed that this novel fabric has great potential for indoor environmental purification and outdoor protection applications.

To enhance the flame-retardant performance of expandable graphite (EG) in rigid polyurethane foam (RPUF), EG particles were encapsulated with inorganic nanoparticles, namely aluminum hydroxide (ATH), forming complex particles EG@ATH with core-shell structure. After the deposition of ATH shell, the expandability of the particles was enhanced from 163 to 197 ml/g, leading to better flame-retardant performance in RPUF. At a content of 11.5 wt%, the limited oxygen index could be increased from 21.5% to 29.6% by EG@ATH, in comparison to 27.5% by the physical mixture of EG and ATH (EG + ATH). Besides, EG@ATH exhibited better performance than EG + ATH on reducing the total smoke release and CO production. It is worth noticing that ATH could react with isocyanate groups, which was confirmed through FTIR. As a result, the interaction between the core-shell particles and the polymer matrix was enhanced, which protected the cell structure of RPUF from destroying by EG particles. The improved flame-retardant performance of EG@ATH, together with their low-cost, easy fabrication and especially friendliness to the environment, make it prospective in applications for flame retardancy of RPUF.A kind of core-shell expandable graphite @ aluminum hydroxide (EG@ATH) as the halogen-free flame retardant for rigid polyurethane foams (RPUF) was designed. This is the first report to prepare encapsulation of expandable graphite with inorganic nanomaterials to increase the expandability. The as-prepared EG@ATH particles showed high efficiency of flame retardancy in RPUF, and improved interface adhesion between EG@ATH particles and RPUF, due to the pre-reaction of ATH layers with polyisocyanate.Download high-res image (198KB)Download full-size image

It is known that ultraviolet (UV) radiation is harmful to human health and affects the long-term stability of many organic materials. It has recently been discovered that blue radiation also poses a danger. In this study, epoxy–ZnO/CdS (EP–ZC) nanocomposites capable of shielding both UV and blue radiation were developed. First, ZnO/CdS nanoparticles were synthesized through the growth of CdS on prefabricated ZnO quantum dots (ZnO QDs). In contrast to ZnO QDs, which only absorb a portion of UV light, the ZnO/CdS nanoparticles exhibited strong absorption over the wavelength region extending from UV light to blue light. Further, their absorption-band range could be controlled by adjusting the Zn/Cd molar ratio. In situ polymerization was employed to prepare the EP–ZC nanocomposites, which were highly transparent at wavelength greater than 500 nm. It was found that the EP–ZC nanocomposites exhibited strong UV-shielding capability and could almost completely block UV light between 200–400 nm as well as more than 80% of the blue light between 400–450 nm when they contained 0.3 wt% ZnO/CdS nanoparticles. Finally, their optical transparency to visible light in the region beyond blue light was the same as that of pure epoxy due to the uniform dispersion of nanoparticles.

As a kind of one-dimensional (1D) nanostructured material, nanorod rutile titanium dioxide (TiO2) with high surface-to-volume ratio shows potential applications in UV-ray shielding, self-cleaning devices, energy conversion and storage. Well dispersed rod-shaped rutile was prepared by hydrolysis of TiCl4 with hydrochloric acid (HCl) solutions and FeCl3 at low temperature. The crystalline form and morphology were characterized by X-ray diffraction (XRD), Raman spectrum and transmission electron microscopy (TEM). The doping of iron was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. A series of experiments were conducted to figure out the effects of reaction conditions on the crystalline form and shape of the powders. The results showed that either change of acids (H2SO4 or HNO3) or varying of cations (NaCl or AlCl3) leaded to a mixed products or pure anatase. A possible mechanism was proposed to explain why the change of minerals or acids would make such a remarkable difference.

Abundant and renewable solar light is an ideal resource for the industrial application of TiO2 photocatalysis in environmental purification. Over the past decades, the pursuit for visible-light photocatalysts with low cost, simple process, and high efficiency remains a challenging task. Here, we report a novel organic–inorganic nanohybrid photocatalyst (conjugation-grafted-TiO2) by chemically grafting conjugated structures onto the surfaces of TiO2 nanoparticles through controlled thermal degradation of the coacervated polymer layer. The interfacial C–O–Ti bonds between TiO2 and conjugated structures can act as the pathway to quickly transfer the excited electrons from conjugated structures to TiO2, therefore contribute to high visible-light photocatalytic efficiency. Our findings provide an economic route to prepare the conjugation-grafted-TiO2 nanohybrid, and develop a routine to improve the photocatalytic efficiency of organic–inorganic hybrid materials through the interfacial interaction.Keywords: conjugation; electron transfer; grafting; nanohybrid; TiO2; visible light;

It is known that ultraviolet (UV) radiation is harmful to human health and affects the long-term stability of many organic materials. It has recently been discovered that blue radiation also poses a danger. In this study, epoxy–ZnO/CdS (EP–ZC) nanocomposites capable of shielding both UV and blue radiation were developed. First, ZnO/CdS nanoparticles were synthesized through the growth of CdS on prefabricated ZnO quantum dots (ZnO QDs). In contrast to ZnO QDs, which only absorb a portion of UV light, the ZnO/CdS nanoparticles exhibited strong absorption over the wavelength region extending from UV light to blue light. Further, their absorption-band range could be controlled by adjusting the Zn/Cd molar ratio. In situ polymerization was employed to prepare the EP–ZC nanocomposites, which were highly transparent at wavelength greater than 500 nm. It was found that the EP–ZC nanocomposites exhibited strong UV-shielding capability and could almost completely block UV light between 200–400 nm as well as more than 80% of the blue light between 400–450 nm when they contained 0.3 wt% ZnO/CdS nanoparticles. Finally, their optical transparency to visible light in the region beyond blue light was the same as that of pure epoxy due to the uniform dispersion of nanoparticles.