Mussel-inspired adhesive gelatin–polyacrylamide hydrogel wound dressing loaded with tetracycline hydrochloride to enhance complete skin regeneration

Even though the global wound care market size was valued at USD 19.83 billion in 2020, it is still a challenge to develop a hydrogel-based wound dressing with a good mechanical property, adhesiveness and antibacterial property.

Transparent Cellulose-Based Films Prepared from Used Disposable Paper Cups via an Ionic Liquid

Paper cups are widely employed in daily life with many advantages, but most of the used paper cups are incinerated or landfilled, due to the great challenge of separating the thin inner polyethylene (PE) coating, causing the waste of energy and the pollution of our environment. Therefore, recycling and converting the used paper cups into high-value materials is meaningful and important. In this work, transparent cellulose-based films were successfully prepared from the used paper cups via 1-allyl-3-methylimidazolium chloride ionic liquid after simple pretreatment. Additionally, the difference in properties and structures of cellulose-based films regenerated in different coagulation baths (water or ethanol) was also explored. It was found that the cellulose-based film possessed good thermal property and displayed better hydrophobicity than the traditional pure cellulose film. Moreover, they also demonstrated good mechanical property and the tensile strength of cellulose-based film regenerated in water can reach 31.5 Mpa, higher than those of cellulose-based film regenerated in ethanol (25.5 Mpa) and non-degradable polyethylene film (9–12 MPa), indicating their great potential as the packaging materials. Consequently, valorization of the low cost used paper cups and preparation of high-valve cellulose-based films were realized simultaneously by a facile and green process.

Microstructure Evolution and Solidification Behavior of a Novel Semi-Solid Alloy Slurry Prepared by Vibrating Contraction Inclined Plate

In this work, based on the A356 alloy, a novel Al–Si–Mg–Cu–Fe–Sr alloy with good mechanical property and high thermal conductivity was developed. The semi-solid slurry of the alloy was prepared via the vibrating contraction inclined plate. The microstructure evolution and solidification behavior of the alloy were investigated. The results demonstrated that, compared with the A356 alloy, the enhanced property of the Al–Si–Mg–Cu–Fe–Sr alloy was associated with the size of primary α-Al grains and morphology of eutectic Si phases. In addition, the preparation process parameters of semi-solid slurries, including the pouring temperature, inclination angle, and vibration frequency, had a crucial effect on the size and morphology of primary α-Al grains. The optimized pouring temperature, inclination angle, and vibration frequency were 670 °C, 45°, and 60 Hz, respectively. In this condition, for the primary α-Al grains, a minimum grain diameter of 64.31 µm and a maximum shape factor of 0.80 were obtained. This work provides a reference for the application of the alloy with high performance in the field of automobile and communication.

Enhanced Multiple Surface Properties of Biometallic Materials by Laser Microprocessing

Metallic materials have been widely used owing to their good mechanical property and high flexibility. However, there are certain limitations for practical applications such as low anti-bacterial, cell adhesion, surface wettability and corrosion resistance property. In this paper, laser microprocessing of titanium (Ti) alloy and magnesium (Mg) alloy has been conducted, respectively. The cell adhesion of Ti6Al4V alloy and Mg-Gd-Ca alloy after laser microprocessing has been investigated. The results show that MC3T3-E1 cells have been successfully adhered to the treated surface and optical density are significantly increased due to hybrid micro/nano structure. Anti-bacterial test shows that the anti-bacterial rates against E. coli of laser-treated surface was up to 72%. Meanwhile, water contact angle has been increased from 57.4° to 135.3° indicating the changing of surface wettability from hydrophilic to hydrophobic. Moreover, corrosion test of Mg-Gd-Ca alloy has been conducted, which has been significantly improved after laser microprocessing. The present work showed that laser surface microprocessing could be a promising technique for fabricating different biomedical property surfaces.

Strategy of extra Zr doping on the enhancement of thermoelectric performance for TiZrxNiSn synthesized by a modified solid-state reaction

Half-Heusler alloys, which possess the advantages of high thermal stability, large power factor and good mechanical property, have been attracted increasing interest in mid-temperature thermoelectric application. In this work, the extra Zr-doped TiZrxNiSn samples were successfully prepared by a modified solid-state reaction followed by spark plasma sintering. It demonstrates that extra Zr doping could not only improve the power factor on account of an increase in Seebeck coefficient but also suppress the lattice thermal conductivity originated from the strengthened phonon scattering by the superlattice nanodomains and the secondary nanoparticles. As a consequence, an increased power factor of 3.29 mW m− 1 K− 2 and a decreased lattice thermal conductivity of 1.74 W m− 1 K− 1 are achieved in TiZr0.015NiSn, leading to a peak ZT as high as 0.88 at 773 K and an average ZT value up to 0.62 in the temperature range of 373 − 773 K. This work gives a guidance for optimizing the thermoelectric performance of TiNiSn-based alloys by modulating the microstructures on the secondary nanophases and superlattice nanodomains.

Speed Controlled Composite Fabrication Using DC Motor

Fabrication process determines the composite quality. Conventional method such as dry- and hand lay-up are commonly used. Dry lay-up method has known to be more controllable and produce less defect composites with good mechanical property. However, this method is more expensive. On the other hand, hand lay-up which is more simple and less expensive, is uncontrollable as well as produces more defect and poorer mechanical properties of composites. In this study, we creates instrument which is able to control wet lay-up fabrication process of Fiber Reinforced Composite Material (FRCM). Instead of using uncontrollable human hands, this instrument utilizes speed controllable paint roller which distributes the resin though all matrix. The result shows that the produced composites have more homogenous resin distribution, smaller size defects, and exhibits stronger mechanical properties compare to the one produced by hand lay-up method. This study is expected to open further innovations on low cost composite fabrication.

Facile Preparation of All Cellulose Self-reinforced Nanocomposites from Bamboo Shoot Fibers

Herein, a novel and facile fabrication method of self-reinforced all cellulose nanocomposite based on 2,2,6,6-tetramethylpiperidine-1-oxy (TEMPO) mediated oxidized bamboo shoot shell fibers was introduced. The composites were thoughtfully characterized. Cellulose nanowhiskers from the bamboo shoot fibers with the diameter of 60–90 nm and a large number of micropores were evenly distributed on the surface of the nanocomposite. Compared with the original fiber, the crystallinity of the composites increased, while the thermal stability decreased. The composite also showed good mechanical property and dimensional stability. It provides a promising and convenient route to obtain firm sheet-materials with micro- or nano- structures from nature cellulose fibers.

Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.