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In this study, carpet waste fibers--namely, polypropylene (PP) and polytrimethylene terephthalate (PTT) in the form of mono microfibers and hybrid combinations--were studied. The optimization of mono fiber parameters for fiber content (0.1, 0.3, and 0.5%) and length (6, 12, and 24 mm [0.236, 0.742, and 0.945 in.]) were conducted to achieve the optimum strength properties and minimize drying shrinkage. The microstructure, pore structure, and fiber-matrix interfacial properties of the optimized samples were characterized at 7, 28, and 90 days by means of scanning electron microscopy (SEM), X-ray micro-computed tomography (CT), and nanoindentation. The research data revealed that the inclusion of either the optimized mono PP fiber (υf = 0.5% and l = 12 mm [0.472 in.]) or PTT fiber (υf = 0.1% and l = 12 mm [0.472 in.]) improved the compressive strength of 4.3% and 16.1%, and the flexural strength by 11.5% and 9.2% at 28 days, respectively. Hybrid carpet fibers (0.4% PP + 0.1% PTT) provided a greater enhancement in compressive strength of 6.6%, and flexural strength by 13% at 28 days. Drying shrinkage mitigation of mortar over 120 days was recorded as 18.4, 22.3, and 25.8%, corresponding to the addition of 0.5% PP fibers, 0.1% PTT fibers, and hybrid PP/PTT carpet fibers. A pore-refining effect was also observed for mortars with 0.5% PP and hybrid PP/PTT carpet microfibers. The SEM images indicated that the trilobal cross-sectional shape of PTT carpet fibers had a stronger anchoring effect with cement hydrates than the rounded shape of PP carpet fibers. Nanoindentation identified the thickness of the fiber-matrix interfacial transition zone (ITZ) as approximately 15 µm (5.9 × 10-4 in.) for both mono PP and PTT fibers. Approximately 50% of the phases in the vicinity of the fiber-matrix interface comprised a porous structure at 7 days. However, the hydration of clinker over the 90-day period promoted the formation of calcium-silicate-hydrate (C-S-H) and portlandite to form a dense microstructure. [ABSTRACT FROM AUTHOR]

Gallium and its alloys, such as eutectic gallium indium alloy (EGaIn), a form of liquid metal, have recently attracted the attention of researchers due to their low toxicity and electrical and thermal conductivity for biomedical application. However, further research is required to harness EGaIn‐composites advantages and address their application as a biomedical scaffold. In this research, EGaIn‐polylactic acid/polycaprolactone composites with and without a second conductive filler, MXene, were prepared and characterized. The addition of MXene, into the EGaIn‐composite, can improve the composite's electrochemical properties by connecting the liquid metal droplets resulting in electrically conductive continuous pathways within the polymeric matrix. The results showed that the composite with 50% EGaIn and 4% MXene, displayed optimal electrochemical properties and enhanced mechanical and radiopacity properties. Furthermore, the composite showed good biocompatibility, examined through interactions with fibroblast cells, and antibacterial properties against methicillin‐resistant Staphylococcus aureus. Therefore, the liquid metal (EGaIn) polymer composite with MXene provides a first proof‐of‐concept engineering scaffold strategy with low toxicity, functional electrochemical properties, and promising antimicrobial properties. [ABSTRACT FROM AUTHOR]

The deposition of textile waste into landfill has reached an unsustainable level and raises serious environmental issues across the world. Transforming textile waste into fiber reinforcement in cementitious composites offers a sustainable resolution toward a circular textile economy. This article presents a comprehensive review of environmental concerns, recycling routes for textile waste, together with an in-depth review of the engineering properties of concrete incorporating recycled textiles. In general, the incorporation of these recycled fibers from textile waste enhances strain capacity, crack control, durability, and energy absorption of concrete via dual effects: bridging action (direct mechanism) and refinement of pore distribution (indirect effect). An improvement in compressive strength can be achieved by the utilization of a small dosage of recycled fibers or recycled fiber fabrics in concrete (strength < 40 MPa). Finally, the cost and environmental benefits for eco-efficient building application are also evaluated to draw the attention of researchers toward these potentially recyclable waste materials. [ABSTRACT FROM AUTHOR]

We aim to develop biocompatible silk dressings, integrated with temperature (nanodiamond) and pH (fluorescein) sensors, capable of monitoring early signs of infections and healing disruptions non-invasively via light-based measurements. These hybrid dressings have strong potential to bring a paradigm shift to the current wound management and care procedures. Introduction: Assessing wound repair requires the removal of dressings, which is painful and disruptive to healing and is based on subjective visual observation of the wound. Improving this process is crucial, as monitoring wound status could enable earlier interventions to reduce the complications that arise from wound infection. Measuring the temperature and pH of the wound surface can provide objective indicators of wound progression1,2. A clinically diagnosed wound infection elevates the temperature by 3-5° C compared to healthy skin1 and the pH of wound fluid rises2 prior to the onset of local infection. Alkaline wound pH enables the invasion of microorganisms, while an acidic wound environment aids healing through protease activity, increased oxygen release, and reduced microbial growth. Hence temperature and pH are useful and robust biomarkers that can provide real-time insights into the healing responses. Methods: Silk fibroin was obtained from B. mori silk cocoons. The extracted silk solution was mixed with nanodiamonds and electrospun into nanofibrous membranes. Confocal and wide field microscopes were used to perform temperature sensing (using green 532 nm excitation) and pH sensing (using blue 470 nm excitation). Human skin keratinocyte (HaCaT) cell lines were used to study cell growth for the hybrid membranes. The in vivo biocompatibility on wound healing was tested on 8-10-week-old C57BL/6J mice, using a murine model of wound healing4. Bacterial suspensions of P. aeruginosa ATCC 9721, E. coli ATCC 11775, and S. aureus CIP 68.5 were used to test the biocidal properties of the hybrid membranes. Results: We showed that electrospun silk membranes embedded with nanodiamond sensors could monitor temperature changes in the wound relevant range of 32-40 °C3. In vitro tests revealed that hybrid membranes enabled eukaryotic cell attachment and promoted healthy cell growth. Furthermore, the membranes were biocidal towards major skin wounds infecting bacteria, P. aeruginosa and E. coli. In an in vivo wound healing model, the hybrid membranes enabled wound healing and did not cause adverse effects on wound closure3. Moreover, the pH-sensitive fluorescein sensor can be encapsulated within a silk matrix to provide measurements of acidity or basicity in vivo5. Conclusions: In conclusion, multiple fluorescent sensors embedded in silk dressings can be used as a platform for biosensing as well as providing a network of fibres that support healthy wound healing processes. [ABSTRACT FROM AUTHOR]

This study evaluated the deterioration in thermo-mechanical and performance properties of the polyaramid and polybenzidimazole fabric used in firefighters' protective clothing after exposure to ultraviolet irradiation, and the effect of weathering. The performance of firefighters' protective clothing plays an important role in protection against heat and physical threats to firefighters. However, frequent exposure to heat and ultraviolet irradiation can deteriorate performance. Test results demonstrated a 79% drop in the residual strength of polybenzidimazole/Kevlar® fabric and a 51% drop in the residual strength of polyaramid (Nomex® IIIA). The results confirmed that heat accelerates the degradation of PBI, resulting in lower performance, an important consideration for firefighters' protective clothing. In this study, a new 'UVPro-Tex' sensor was developed, with the capability to record the amount of ultraviolet irradiation absorbed by the fabric. When the amount of the absorbed ultraviolet irradiation reaches a critical value, the sensor warns the wearer of the end-of-life of the garment. [ABSTRACT FROM AUTHOR]

This research investigated the transport properties (such as thermal resistance, water vapor resistance and air permeability), moisture management capacity and sensorial properties of some knitted structures of superabsorbent polyacrylate in order to explore their potential as next-to-skin layers in firefighters’ protective clothing in Australia. Test results using these fabrics were compared with the currently used next-to-skin woven fabric. Three different knitted structures (i.e. jersey, rib and interlock) were selected for the study in addition to the current woven fabric in use by Australian firefighters. It was observed that the knitted fabric samples of superabsorbent polyacrylate retained higher amounts of water compared to the fabric sample currently used in the firefighters’ clothing. However, the woven fabric sample dried at a faster rate. Hence, a blended fabric of polyacrylate with the current Nomex® fabric can help in higher sweat absorption and faster drying. The thermal and water vapor resistance of jersey fabric was the lowest, which may better facilitate the transfer of metabolic heat and vapor to the environment, resulting in better thermal comfort. Furthermore, all the fabric samples showed a low coefficient of friction (∼0.2), which indicated less tactile discomfort if the fabrics are worn as the next-to-skin layer in the firefighters’ clothing. The overall moisture management properties of the fabric samples were rated as fair to good. The findings of this research suggest that the superabsorbent material has the potential to be used in place of the existing next-to-skin layer of firefighters’ protective clothing, with better sweat absorption capacity and thermal comfort. [ABSTRACT FROM AUTHOR]

Firefighters are often exposed to high temperature environments which can lead to dehydration and high body temperatures. Consequently, a reduction in mental concentration and an increase in fatigue levels will occur. The aim of this study is to investigate the implementation of Phase Change Material (PCM) into firefighter internal clothing to improve thermal protection. Both organic and inorganic types of PCM have high heat absorbing capacity and therefore can be used as thermal energy storage to enhance firefighter's body cooling and thermal protection. Experimental prototypes were constructed using cotton drill shirts, cotton mesh pockets and PCM packaged into aluminium pouches. The selected type of PCM studied was of paraffin wax as organic PCM and Glauber's salt as inorganic PCM which were used to create samples to be tested under simulated conditions. To increase the thermal conductivity of PCMs, the addition of copper metal foam to the paraffin wax was also analysed. The results indicated that the copper foam was able to reduce the melting time whilst evenly distributing the heat. This paper will provide detailed thermal analysis of different category of PCM and comparison of their respective heat absorbing performance, to achieve maximum thermal protection for firefighters via fully passive cooling approach. This implementation of PCM based firefighting clothing will lead to an improvement in firefighter's cooling sensations, potentially increase their operation time, better mental concentration. [ABSTRACT FROM AUTHOR]

In the current study, we describe the synthesis, material characteristics, and cytocompatibility of conducting poly (ɛ-caprolactone) (PCL)-based nano-composite films. Electrically conducting carbon nano-fillers (carbon nano-fiber (CNF), nano-graphite (NG), and liquid exfoliated graphite (G)) were used to prepare porous film type scaffolds using modified solvent casting methods. The electrical conductivity of the nano-composite films was increased when carbon nano-fillers were incorporated in the PCL matrix. CNF-based nano-composite films showed the highest increase in electrical conductivity. The presence of an ionic solution significantly improved the conductivity of some of the polymers, however at least 24 h was required to absorb the simulated ion solutions. CNF-based nano-composite films were found to have good thermo-mechanical properties compared to other conducting polymer films due to better dispersion and alignment in the critical direction. Increased nano-filler content increased the crystallisation temperature. Analysis of cell viability revealed no increase in cell death on any of the polymers compared to tissue culture plastic controls, or compared to PCL polymer without nano-composites. The scaffolds showed some variation when tested for PC12 cell attachment and proliferation, however all the polymers supported PC12 attachment and differentiation in the absence of cell adhesion molecules. In general, CNF-based nano-composite films with highest electrical conductivity and moderate roughness showed highest cell attachment and proliferation. These polymers are promising candidates for use in neural applications in the area of bionics and tissue engineering due to their unique properties. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 853-865, 2016. [ABSTRACT FROM AUTHOR]