Extensive fashion and textiles research have adopted fused filament fabrication in three-dimensional printing. However, much research has dedicated itself to experimenting with rigid materials that ...lack the capability to mimic conventional textile-like garments. The commercialization of thermoplastic polyurethane/elastomers have posed greater potentials for developing flexible polymer-textile composites. Such materials will enable the creation of ergonomically designed textiles with optimized flexibility and elasticity aimed for garments. This study examines the influence of polymers, textile surface roughness, and nozzle temperature on peel resistance and polymer coefficient of friction/surface roughness. T-peel tests (ISO 11339:2022), cross-sectional microscopic image analysis, and a KES-FB4-A surface tester were used to evaluate the surface quality and peel resistance between polymer-textile assemblies. Our results revealed thermoplastic-polyurethane-knitted combinations to demonstrate superior peel resistance owing to knitted structure’s pore structure and thermoplastic polyurethane’s lower melting temperature. Moreover, a significant increase in peel strength was found at 260°C (above recommended printing temperature) in thermoplastic-polyurethane-knitted fabrics at 3.24 N/mm. While the coefficient of friction remained similar, a rougher surface quality was discovered at higher temperatures in thermoplastic polyurethane at 3.85 μm warp/4.35 μm weft. In thermoplastic elastomer, the roughest surface was found at 240°C measuring 3.65 μm warp/3.37 μm weft. This study fills a lack of research into flexible polymer-textile composites by suggesting parameters for achieving an equilibrium between optimal adhesion and polymer layer surface quality.
In the present study, properties of pectin from grapefruit (Citrus paradisi Macf. cv. Changshanhuyou) peel extracted by ultrasound-assisted extraction (UP), were compared with those of pectin ...extracted by conventional heating extraction (CP). UP exhibited a lower molecular weight (Mw) but more concentrated Mw distribution than CP. Although both UP and CP were high-methoxyl pectin, UP showed significantly lower degree of methoxylation but higher degree of acetylation. Monosaccharide composition analysis showed that the molecular structure of UP possessed more branch chains than CP, but little difference was observed in the chemical structures between UP and CP from FT-IR and NMR spectra analysis. X-ray diffraction (XRD) analysis further confirmed that UP had decreased level of crystallinity than CP. Moreover, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated UP had higher thermal stability. UP exhibited lower apparent viscosity and elasticity than CP, showing that ultrasound affected the rheological properties of pectin. Besides, antioxidant activity and lipase inhibitory capacity of UP significantly enhanced compared with CP.
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•Structure and properties of pectin were affected by different extraction methods.•Ultrasonic extracted pectin had lower molecular weight and polydispersity.•Ultrasonic extracted pectin had higher percentage of side chains.•Thermal stability of ultrasonic extracted pectin were advantageous.•Ultrasonic extracted pectin exhibited excellent bioactivity.
This study examines the utilization of plantain peels (Musa paradisiaca) as a strengthening component in aluminum metal matrix composites (AMMCs) for the purpose of cost reduction and the utilization ...of eco-friendly materials. The composites were manufactured using the stir casting method, with varying plantain peel contents ranging from 0 % to 25 %. Mechanical assessment revealed a notable increase of more than 80 % in microhardness as the plantain peel content increased, which was attributed to enhanced interfacial bonding and effective dispersion of reinforcements. The maximum recorded hardness was 40 HRB for the composite containing 25 % plantain peels. Electrochemical examinations indicated a reduction in corrosion rate, with the lowest rate observed at 6.80 mm/year for the composite with 25 % plantain peel, underscoring the inhibitive impact of the plantain peels. Variations in electrical resistivity and conductivity were observed due to the non-uniform distribution of plantain peels, with resistivity values ranging from 5.06 Ωm to 5.13 Ωm and conductivity ranging between 0.1950 (Ωm)−1 and 0.1975 (Ωm)−1. Analysis of the microstructure using SEM/EDS and XRD techniques confirmed the successful integration of plantain peels into the matrix, revealing distinct diffraction patterns and the formation of intermetallic phases such as Al(ZnSn2), Al(Mn,Fe)Cu, and Al(Mn,Fe2O3). The results indicate that plantain peels present a feasible and sustainable option for reinforcing AMMCs, thereby improving their mechanical properties and corrosion resistance.
Hydrogel adhesion regulation remains a key challenge in applications of stretchable electronics, tissue engineering, and soft robotics. Whereas existing strategies are focused on enhancing adhesion, ...the underlying mechanics of on-demand mechanical regulation from adhesion promotion to adhesion reduction receives insufficient attention. We propose an effective method to manipulate the energy process zone near the crack front by invoking periodic elastic heterogeneity, whose adhesion toughness exhibits high dependence on the periodic structures and peeling direction. Without modifying surface chemistry, the adhesion of heterogeneous interfaces implemented by 3D printing can enhance peak force by 6-fold or weaken interfacial toughness to 1/30, as compared to the case of a homogeneous interface. Based on a variational principle, analytical formulations and finite element simulations are performed to quantify the heterogeneous behaviors. The analysis captures the instability phenomenon and predicts the maximum peel force. Combined experimental, theoretical, and finite element results demonstrate the effects of geometric parameters and peeling directions on the overall adhesion toughness. This data elucidates an energy storage mechanism, namely that the discrete elastic ligaments free of lateral constraints could enable the interface to accommodate large stretching and store intensified strain energy. The results also indicate the necessity and significance of peeling directions. The work provides a design guideline for on-demand enhancement and detachment in hydrogel interface applications.
In the present study, apple peel polyphenols (APP) were incorporated into chitosan (CS) to develop a novel functional film. Scanning electron microscopy, Fourier transform-infrared spectroscopy and ...thermogravimetric analyses were performed to study the structure, potential interaction and thermal stability of the prepared films. Physical properties including moisture content, density, color, opacity, water solubility, swelling ration and water vapor permeability were measured. The results revealed that addition of APP into CS significantly improved the physical properties of the film by increasing its thickness, density, solubility, opacity and swelling ratio whereas moisture content and water vapor permeability were decreased. Tensile strength and elongation at break of the CS-APP film with 1% APP was 16.48MPa and 13.33%, respectively, significantly lower than those for CS control film. Thermal stability of the prepared films was decreased while antioxidant and antimicrobial activities of the CS-based APP film were significantly increased. CS-APP film with 0.50% APP concentration exhibited good mechanical and antimicrobial properties, indicating that it could be developed as bio-composite food packaging material for the food industry.
•Chitosan (CS) based films incorporated with apple peel polyphenols (APP) were prepared.•Prepared CS-APP films were characterized by SEM, FT-IR and TGA.•Antimicrobial and antioxidant activities of prepared films were also evaluated.•CS-APP films exhibited good potential to be used a bio-composite food packaging.
Pomegranate (Punica granatum L.) peel powder was incorporated into fish gelatin film-forming solution (FFS) to develop an active packaging film. The physical, mechanical, antioxidant and ...antimicrobial properties of the films were investigated. Fish gelatin film without pomegranate peel powder (PPP) was used as the control film. The water vapor permeability (WVP) of the fish gelatin films increased as the content of incorporated PPP increased. However, films with higher PPP contents exhibited higher tensile strengths (TS values), which ranged from 7.48 to 8.02 MPa. PPP significantly (p < 0.05) improved the antioxidant properties of the films in both DPPH and ABTS radical-scavenging activity tests. The film's antimicrobial activities also increased significantly (p < 0.05) after the incorporation of PPP. Staphylococcus aureus (S. aureus) was found to be the most sensitive bacterium to the active film, followed by Listeria monocytogenes (L.monocytogenes) and Escherichia coli (E. coli). The largest inhibition zone (7.00 mm) was observed for S. aureus around the film incorporated with 5% (w/w) PPP. These results revealed that fish gelatin containing PPP has great potential as an active film with antioxidant and antimicrobial properties, and thus it can help maintain the quality and prolong the shelf life of food products.
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•Fish gelatin films with pomegranate peel powder (PPP) were produced.•The presence of peel powder contributed to the yellowness of the films.•Films containing pomegranate peel powder exhibited antioxidant properties.•The produced films with 5% PPP had the highest antibacterial activity against Staphylococcus aureus.
Aini N, Herdawan IS, Sustriawan B, Setyawati R, Kurniawan REK, Suliman NM, Arsyistawa HS, Indarto. 2024. Characterization of melon (var Sky Rocket) peel pectin using microwave-assisted extraction at ...different powers and extraction times. Biodiversitas 25: 1528-1535. Pectin is a heteropolysaccharide molecule that can be used as a thickening agent due to its ability to bind large amounts of water. Pectin can be obtained from fruit peels containing pectic compounds, one of which is melon. A modern extraction technique such as Microwave-Assisted Extraction (MAE) is appropriate because it requires a relatively short time and lower costs. The objective of the research was to determine the effect of power and time on the pectin extraction from melon peel using microwave-assisted extraction. Sample preparation was done by drying the melon peel and then crushing and sieving it to produce melon peel powder. The powder was extracted using combinations of various microwave power of 180 (D1), 270 (D2), and 360 (D3) watts and extraction time variations of 3 (W1), 5 (W2), and 7 (W3) minutes. The results showed that the best treatment combination was extraction using microwave power of 270 watts for 3 minutes, which produced melon peel pectin with a yield of 6.4%, moisture content of 8.85%, ash content of 7.73%, equivalent weight of 1,810.07 mg, methoxyl content of 2.46%, galacturonic acid content of 95.74%, and degree of esterification of 22.02%. Melon peel, usually considered waste, can be used more optimally as a source of pectin.
•Treatment with 1 mmol L−1 melatonin maintained postharvest quality of ‘Fuji’ apples.•Melatonin treatment reduced weight loss and peel injury in stored apples.•Melatonin decreased ethylene production ...by inhibiting ethylene synthesis genes.•Melatonin treatment reduced MDA concentrations in apples during storage.•Melatonin treatment promoted antioxidant capacity in apples during storage.
The effects of treatment with melatonin on ripening of ‘Fuji’ apples during storage at 1 °C for 56 d were investigated. The apples were harvested at the commercial ripening stage and treated with 1 mmol L−1 melatonin. Compared with the control, melatonin treated apples had significant reduced ethylene production (28 d–56 d) and weight loss (14 d–56 d) during storage (p < 0.05). Also, the melatonin treatment maintained better apple skin structure throughout storage. The reduced ethylene production was regulated by the decreased expressions of MdACO1, MdACS1, MdAP2.4 and MdERF109, based on RNA-Seq analysis, which was validated using qRT-PCR analysis. Moreover, the activity of 3 enzymes, including peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), were significantly increased in melatonin treated fruit (p < 0.05). Taken together, this study highlights the inhibitory effects of melatonin in ethylene biosynthesis and factors influencing postharvest quality in apple.
Bioactive edible packaging films were developed by incorporating different concentrations (5%, 10%, 15, and 20%) of tea polyphenol (TP) into the pomelo peel flour (PPF) in order to modify the ...functional properties of the films. The proximate chemical composition of PPF was firstly determined. The PPF based films were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), together with the determination of physical, optical, mechanical, antioxidant and antimicrobial properties of the films. The incorporation of TP significantly improved the antioxidant activity and antimicrobial activity of the films, while induced a decrease in the transmittance, moisture content and elongation at break. Addition of TP at an appropriate level (10% TP) led to stronger intermolecular interactions and more compact microstructure, and thus enhanced the water barrier properties and tensile strength of the films. Potential packaging application was evaluated using soybean oil in an oven at 50 °C for 30 days. The PPF/TP composite film significantly decreased peroxide value (POV) to delay oil oxidation during storage. These results revealed that pomelo peel is a good film-forming substrate and tea polyphenol has a good potential to be incorporated into pomelo peel to prepare biodegradable/edible active films for food applications.
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•Pomelo peel was a good film-forming substrate because of its high content of biopolymers.•Bioactive edible films were successfully prepared by pomelo peel flour (PPF) and tea polyphenol (TP).•Homogeneous and flexible composite films showed good physical properties.•The films incorporated with tea polyphenol exerted both antioxidant and antimicrobial activity.•The PPF/TP composite films could delay oil oxidation during storage suggesting a potential for food packaging application.
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