Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a “flexible, stretchable, and flame retardant” way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H₂O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.

In order to acquire a tetracalcium phosphate/magnesium phosphate (TTCP/MPC) composite bone cement that combines the excellent bioactivity of TTCP and high mechanical strength of MPC, the cement was made and the compressive strength, phase composition of hardened cement, degradation in vitro, and tissue responses in vivo by implantation of TTCP/MPC in bone defect of rabbits were investigated. The results showed that TTCP/MPC was with a markedly better mechanical property than MPC. Moreover, compared with MPC, TTCP/MPC showed significantly delayed degradability in simulated body fluid. To investigate the in vivo biocompatibility and osteogenesis, the TTCP/MPC samples were implanted into bone defects in rabbits. Histological evaluation displayed that the introduction of TTCP into MPC enhanced the efficiency of new bone formation. TTCP/MPC also showed good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that TTCP/MPC meets the basic requirements of bone tissue engineering, has an obvious clinical advantage over MPC and is promising to be applied in orthopedic, reconstructive and maxillofacial surgery.

Solid waste red mud was modified by HCl leaching. The structure property and composition of modified red mud were investigated by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET). Under UV irradiation, methyl orange (MO) aqueous solution was photodegraded by modified red mud. The obtained results showed that the specific surface area of modified red mud was 317.14m2/g, which was about 40 times higher than that of the normal red mud. After UV irradiation for 50min, the removal percentage of MO reached 94.2%. The study provided a novel way for the application of red mud to the photocatalytic degradation of organic wastes. Solid waste red mud was modified by HCl leaching. The structure property and composition of modified red mud were investigated by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET). Under UV irradiation, methyl orange (MO) aqueous solution was photodegraded by modified red mud. The obtained results showed that the specific surface area of modified red mud was 317.14m2/g, which was about 40 times higher than that of the normal red mud. After UV irradiation for 50min, the removal percentage of MO reached 94.2%. The study provided a novel way for the application of red mud to the photocatalytic degradation of organic wastes.

A coaxial integrated fiber-shaped self-powered CNT-PVA-GAT photoelectrochemical sensor with rapid ion/electron transport and superior methane adsorption and light absorption was constructed, featuring outstanding sensing performance toward methane.