The work reports a novel strategy for combining polymers and metal–organic frameworks (MOFs) into composites for adsorption applications. Calcium silicate (CaSiO3) was introduced into acrylonitrile butadiene styrene/thermoplastic polyurethane (ABS/TPU) alloy, and the CaSiO3/ABS/TPU skeleton was fabricated by 3D printing technology. The Ca-MOF was directly loaded on the surface of acetone-etched 3D skeleton by in-situ growth method. The obtained 3D skeleton was characterized and the performance of methylene blue (MB) adsorption was determined. It is clear that Ca-MOF is successfully loaded on the surface of 3D skeleton due to the presence of CaSiO3. The MB adsorption ratios of the solutions with initial concentrations of 50, 100 and 200 mg/L at the equilibrium time (5 h) are 88%, 88% and 80%, respectively, revealing good MB adsorption performance of the 3D skeleton. The MB adsorption ratio remains 70% at six runs of adsorption–desorption experiment, indicating the excellent recovering property of the skeleton. The results show that the prepared CaSiO3/ABS/TPU 3D skeleton is a candidate adsorbent for printing and dyeing effluent treatment.
Tuning the high properties of segregated conductive polymer materials (CPCs) by incorporating nanoscale carbon fillers has drawn increasing attention in the industry and academy fields, although weak interfacial interaction of matrix-filler is a daunting challenge for high-loading CPCs. Herein, we present a facile and efficient strategy for preparing the segregated conducting ultra-high molecular weight polyethylene (UHMWPE)-based composites with acceptable mechanical properties. The interfacial interactions, mechanical properties, electrical properties and electromagnetic interference (EMI) shielding effectiveness (SE) of the UHMWPE/conducting carbon black (CCB) composites were investigated. The morphological and Raman mapping results showed that UHMWPE/high specific surface area CCB (h-CCB) composites demonstrate an obviously interfacial transition layer and strongly interfacial adhesion, as compared to UHMWPE/low specific surface area CCB (l-CCB) composites. Consequently, the high-loading UHMWPE/h-CCB composite (beyond 10 wt% CCB dosage) exhibits higher strength and elongation at break than the UHMWPE/l-CCB composite. Moreover, due to the formation of a densely stacked h-CCB network under the enhanced filler-matrix interfacial interactions, UHMWPE/h-CCB composite possesses a higher EMI SE than those of UHMWPE/l-CCB composites. The electrical conductivity and EMI SE value of the UHMWPE/h-CCB composite increase sharply with the increasing content of h-CCB. The EMI SE of UHMWPE/h-CCB composite with 10 wt% h-CCB is 22.3 dB at X-band, as four times that of the UHMWPE/l-CCB composite with same l-CCB dosage (5.6 dB). This work will help to manufacture a low-cost and high-performance EMI shielding material for modern electronic systems.
Due to the increasing amounts of textile waste, textile to textile recycling is of prime concern. Polyethylene terephthalate (PET) represents the most extensively used type of chemical fiber. Its spinnability suffers from impurities and degradation in the processing, which limits its recycling to new fibers. Here, recycled polyester is blended with a small amount of recycled nylon, and the regenerated fibers, which demonstrated good mechanical properties, were obtained via a melt spinning machine. The mechanical properties, thermal properties, rheological properties, and chemical structure of the modified recycled fibers were investigated. It was found that when compared with rPET-T fibers, the elongation at break of rPET-Ax fibers increased to 17.48%, and the strength at break decreased to 3.79 cN/dtex. The compatibility of PET and PA6 copolymer were enhanced by copolymers produced by in-situ reaction in the processing. Meanwhile, the existence of PA6 increases the crystallization temperature and improves the hydrophilicity of the fibers. This study realized the high-value recycling of waste PET fabric to new fibers, which opens a door for the large utilization of waste textiles.
Both adsorption and photocatalysis are considered to be effective methods for removing organic contaminants from dye wastewater. In this study, the construction of 3D skeletons based on the nanoparticles ZnO and ABS/TPU/calcium silicate (CaSiO3) (shortened as ATC) were fabricated via fused deposition molding (FDM) technology. Characterization by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) depicted that ZnO nanospheres had been successfully grown on the 3D skeleton surface with an enlarged specific surface area. As the results of the RhB adsorption and photocatalytic degradation experiments showed, the removal ratio of RhB onto the ZnO-ATC skeleton was as high as 97.94% and the synergistic effect of adsorption and photocatalysis greatly shortened the RhB degradation time under ultraviolet light irradiation. The nanocomposites synthesized in this study showed a significant removal ability for organic pollutants, and could effectively overcome the limitation of the secondary removal of photocatalysts.
Photocatalytic degradation of an antibiotic by utilizing inexhaustible solar energy represents an ideal solution for tackling global environment issues. The target generation of active oxidative species is highly desirable for the photocatalytic pollutants degradation. Herein, aiming at the molecular structure of tetracycline hydrochloride (TC), we construct sunlight-activated high-efficient catalysts of TiO2-eggshell (TE). The composite ingeniously utilizes the photoactive function of TiO2 and the composition of eggshell, which can produce oxidative ·CO3− species that are especially active for the degradation of aromatic compounds containing phenol or aniline structures. Through the synergistic oxidation of the··CO3− with the traditional holes (h+), superoxide radicals (·O2−) and hydroxyl radicals (·OH) involved in the photocatalytic process, the optimal TE photocatalyst degrades 92.0% TC in 30 min under solar light, which is higher than TiO2 and eggshell. The photocatalytic degradation pathway of TC over TE has been proposed. The response surface methodology is processed by varying four independent parameters (TC concentration, pH, catalyst dosage and reaction time) on a Box–Behnken design (BBD) to optimize the experimental conditions. It is anticipated that the present work can facilitate the development of novel photocatalysts for selective oxidation based on ·CO3−.
Photocatalysis is widely acknowledged as an efficient and environmentally friendly method for treating dye-contaminated wastewater. However, the utilization of powdered photocatalysts presents significant challenges, including issues related to recyclability and the potential for secondary pollution. Herein, a novel technique based on 3D printing for the synthesizing of iron oxide (Fe2O3) involving chlorella was presented. Initially, chlorella powders were immobilized within acrylonitrile butadiene styrene (ABS) and thermoplastic polyurethane (TPU) substrate plastics using melt extrusion technology. Subsequently, these composite materials were transformed into ABS/TPU/chlorella skeletons (ATCh40), through fused deposition molding (FDM) technology. The integration of Fe2O3 onto the ATCh40 (ATCh40-Fe2O3) skeletons was accomplished by subjecting them to controlled heating in an oil bath. A comprehensive characterization of the synthesized materials confirms the successful growth of Fe2O3 on the surface of 3D skeletons. This strategy effectively addresses the immobilization challenges associated with powdered photocatalysts. In photocatalytic degradation experiments targeting methyl orange (MO), the ATCh40-Fe2O3 skeletons exhibited a remarkable MO removal rate of 91% within 240 min. Under conditions where the pH of MO solution was maintained at 3, and the ATCh40-Fe2O3 skeletons were subjected to a heat treatment in a 150 °C blast drying oven for 2 hours, the degradation rate of MO remained substantial, achieving 90% removal after 6 cycles. In contrast, when the same synthetic procedure was applied to ABS/TPU (AT) skeletons, the resulting product was identified as α-FeOOH. The MO removal rate by the AT-α-FeOOH skeletons was considerably lower, reaching only 49% after 240 min. This research provided a practical approach for the construction of photocatalytic devices through the use of 3D printing technology.