Fibers and Polymers最新文献

In particular, foams have been given a lot of attention in the packaging industry and other sectors over the years. In this study, low-density white lactirofoam is created using micronized polylactide particles, and the essence of making it environmentally friendly is considered. A new approach covering four key stages was used in the synthesis of lactirofoam, involving a ring-opening polymerization process for L-lactide, emulsion micronization solution preparation, deposition, and molding. Characterization by ATR-IR and ¹H-NMR techniques confirmed the synthesis of the polylactide polymer. The optical micrograph showed that the process of micronization of the lactirofoam particles was quite efficient. The GPC analysis confirmed that the key to controlling the molecular weight of the final polymer during ROP in order to achieve the desired density of lactirofoams was a specific choice of molar ratios for starting monomers. In addition, lactirofoam’s temperature properties have been determined using TG/DTG/DTA. With the molecular weight of the polymer, they confirmed an increase in the thermal stability of lactirofoam.

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Impact to the head during an accident, severe braking or other driving accidents are one of the causes of injury in the passengers of road vehicles. This issue is much more evident for racing car drivers due to the high speed of the car and maneuvering. One of the driver’s protective tools in this situation is a helmet. In this research, the possibility of using spacer fabric as a shock absorber for the car passenger’s head when crossing over road irregularities is investigated. For this purpose, the effect of the diameter, length and density of the yarns forming the spacer fabric, their inclination angle and the thickness of the top layer of the fabric on the impact force on the head is investigated. First, using the finite element model of the fabric, the effect of the above parameters on the force–displacement characteristics of the fabric is studied. In order to simulate the vehicle movement on the road irregularities, a four degree of freedom model of the vehicle and its passenger has been used. By solving the differential equations of motion of the model using the Rang Kuta method, the impact forces on the head have been obtained for different parameters of the fabric. The results of the simulation showed that by increasing the yarn diameter from 0.2 to 0.3 mm, the average force on the head decreases by 21.9%.

Demand for textiles is increasing owing to human population growth, social competition, and fashion trends. This growth in demand is met at the cost of contamination of tons of fresh water with dye. In this study, microwave irradiation was used in dyeing of textiles as a method of minimizing this environmental threat. The microwave works through dielectric heating and realizes its effect on different dye structures. Dyeing was performed on six different reactive red dyes based on an H-acid coupling component with dissimilar substituents. UV–visible spectroscopy measurements revealed that auxochromes do not impart color to the dyes, but still have a great impact on color depth and hue. The zeta potential and temperature rise per minute under microwave irradiation were both affected by changes in the dye concentration and structure. The dyeing of cotton samples was performed by the exhaust microwave dyeing technique with an optimized recipe and conventional dyeing with a standard recipe for comparison. The color strength values obtained from the experiments revealed that the microwave technique provides better results by consuming 86.67% less salt with a lower liquor volume. The exhaustion and fixation values further confirmed this assessment. The color fastness against basic conditions was similar with both techniques; hence, the microwave can be considered to be a better technique in all aspects. Furthermore, the dye D195 was found to be more effective in achieving higher color depths with a less concentrated effluent indicating that the synthesis of high-performance dyes requires care in the selection of substituents.

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In this study, we report a simple method for producing citric-acid-modified cellulose adsorbent from coir waste for the remediation of cationic methylene blue dyes. The modification of cellulose nanofibers with citric acid increased the surface area and porosity of the adsorbent, thereby enhancing its adsorption capacity. The morphology and chemical structure of the modified adsorbent were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) techniques. The adsorption of methylene blue (MB) onto the adsorbent was studied at different pH, MB concentrations, adsorbent dosages, temperatures, contact times, and in the presence of other salts. The adsorbent demonstrated a remarkable removal efficiency of 99% at dye concentration of 10 mg/L. The maximum adsorption capacity of the adsorbent was 156.25 mg/g at an initial dye concentration of 15 mg/L, adsorbent dosage of 0.15 g/L, pH of 9, and temperature of 303 K after 240 min of duration. The adsorption kinetics and equilibrium adsorption isotherms were consistent with pseudo-second-order kinetic and Langmuir isotherm models, respectively. The thermodynamic parameters indicated that the removal of methylene blue dye by the modified adsorbent was endothermic, and spontaneous in nature. Furthermore, reusability experiments revealed that the adsorbent exhibited 93% efficiency, even after five cycles of adsorption and desorption.

Over the generations, the textile industry has built a reputation as one of the world’s biggest water consumers and polluters. Today, the shift in environmental and social awareness impacts textile markets and production techniques. This paper describes a unique way to reduce the intake of freshwater for the dyeing process in the textile industry. Efforts have been made to utilize reactive, basic, and direct dye-bath effluents directly as liquor in polyester dyeing for 0.5, 2, and 4% shade of primary colors. The obtained result shows that the fabric dyed in effluents has acceptable color strength and color difference as that of the conventional dyeing process with freshwater. The fastness properties of all the dyed fabrics were good to excellent. Thus, this process can effectively reduce the intake of freshwater by about 30,000 L/ton. Also, it has an economic benefit and can save 450 Rs/ton. Thus, the findings prove that effluents generated from the cotton dyeing unit can be used directly for polyester dyeing.

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Bean-flour printing is a traditional craft with local characteristics that originated in China. However, its survival today faces various obstacles, especially the lack of innovation. This study has developed a technique to produce multi-color prints on cotton textiles using bean flour and quicklime as pastes and resist agents. It was found that bean flour could be mixed with various natural dyes and colors in the resist part. The thickness of the bean flour pastes had a direct effect on clarity and brightness of the covered area during printing process. In multi-color printing, the hue of the resist area was closely related to the dyes used and the thickness of the bean flour pastes. In addition, the thickness of the bean-flour pastes played a crucial role in rub resistance of the colors and the overall durability of the printed design. In conclusion, this innovative method of multi-color printing not only preserved but also revitalized the ancient art of bean flour printing.

Healthcare devices play an important role in the diagnosis, treatment, and monitoring of patients. MXene, as a new member of the two-dimensional materials family, has characteristic conductivity, hydrophilicity, biocompatibility, and antibacterial ability, which makes it suitable for fabricating healthcare devices. By combining MXene with self-healing polymers, durable and self-healing healthcare devices that are resistant to mechanical damage during dynamic work can be achieved. Thanks to the dual biocompatibility of MXene and polymers, the self-healing MXene/polymer composites have the functions of sensing and self-healing in vivo and in vitro, serving as a basis for modern healthcare devices. Herein, we summarize the recent progress of using MXene/polymer composites to fabricate skin-friendly sensors with self-healing capability: universal strategies for fabricating self-healing MXene sensors and their fundamental performance are discussed, and biomedical healthcare applications are demonstrated. This review aims to provide a reference for MXene-based self-healing healthcare electronics and facilitate further efforts in the innovation of modern biomedical devices.

In the continuous textile processing, conventional padding is the most commonly used technique for fabric dyeing. Pad dyeing consumes the substantial water, energy, and harmful chemicals. Recently, foam dyeing has been reported as a sustainable alternative to the pad dyeing for cotton fabric. However, there is a lack of research on the foam dyeing of polyester fabrics. Foam dyeing of polyester fabrics would face various challenges such as dye-uptake resistance due to its hydrophobic properties, foam optimization difficulties, and desired performance achievement. For the first time, this paper evaluates the foam dyeing of the polyester fabrics using three disperse dyes. This paper performs foam dyeing of polyester fabric using three disperse dyes, two foaming agents, and two stabilizers. The foam recipes were optimized for each color, each foaming agent, and each stabilizer. The optimized foam recipes were applied on the polyester fabric samples using a foam coating machine. Performance of the resultant foam-dyed fabric was compared with the fabric dyed with conventional pad-dry-cure method. Testing of the dyed fabric parameters included shade depth, color fastness, tearing strength, and air permeability. Results exhibited the successful application of foaming recipes and competitive performance. Subsequently, foam dyeing of polyester fabrics offers substantial cost savings, water saving, and energy saving.

In recent years, wettability materials with pH-responsive have attracted increasing attention in oil/water separation applications. However, these materials were limited by the pH range and infiltration time. Herein, a simple operational procedure is proposed to prepare banana nanocellulose cryogels with pH-responsive switchable wettability to realize these outstanding performances. Alkyl-modified cryogels (BCNC-MS) are obtained by adding methyltrimethoxysilane (MTMS) to the banana nanocellulose (BCNF) suspension. BCNC-MS are soaked in the carboxyl-modified solution to produce pH-responsive cryogels (BCNC-MS-SA). The carboxyl-modified solution is made from succinic anhydride (SA), (3-aminopropyl)triethoxysilane (KH550), and N,N-dimethylformamide (DMF) in a molar mass ratio of 1:1:18. The key to achieving the pH-response is the protonation and deprotonation of the carboxyl groups. SEM demonstrates that the modification keeps the three-dimensional porous structure of the cryogel, and the results of EDS, FTIR, and XPS show the success of alkyl and carboxyl modifications. BCNC-MS-SA can realize hydrophilic/underwater oleophobic (θ_water = 0°) and hydrophobic/underwater oleophilic (maximal θ_water = 135°) wettability transitions after treatment with different pH solutions. Compared with other pH-responsive oil/water separation materials, BCNC-MS-SA performs well in pH = 1 and pH = 13 environments, and the shortest infiltration time is only 3 s. With a porosity of 93.80%, BCNC-MS-SA possesses excellent adsorption capacity (10–40 g/g), oil/water separation efficiency (> 92%), and adsorption cycle performance (15 cycles) even for viscous oils. Moreover, BCNC-MS-SA has satisfactory stability. Cryogels are made of banana nanocellulose, and they are inexpensive and can be easily degraded. BCNC-MS-SA has great potential in practical applications such as oil removal and purification of oily wastewater.

Natural-derived wound dressing products with on-demand antibacterial properties have recently captured accentuated attention in the application field of dermal wound treatment. Herein, an affordable approach to the fabrication of electrospun membranes employing polycaprolactone (PCL), Poloxamer 407 (POX), and Calophyllum inophyllum oil (CIO) for antibacterial dressings is demonstrated. Briefly, the influence of POX and CIO concentration on the obtained membranes is evaluated to determine the optimal parameters for dressing applications. The surface morphology, chemical compositions, surface wettability, moisture permeability, mechanical properties, and antibacterial activity of the obtained membranes are evaluated. The results show that the PCL_POX_CIO membranes exhibit the enlargement of fiber diameter, indicating a causal correlation between the PCL and CIO concentration. In addition, POX concentration is discovered to have a positive impact on water absorption capacity with recorded WCA of 0°, however, reduces mechanical strength due to bead formations. Specifically, when the CIO content reached 15 v/v%, the recorded inhibition zone was measured to be 15.7 ± 1.34 (mm). Furthermore, our study underscores the significant antibacterial activity of CIO in agar-diffusion tests against Staphylococcus aureus strains. Despite several limitations, the successful fabrication of the PCL_POX_CIO membranes open an economically sustainable approach for the scalable fabrication of antibacterial wound dressing.

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