The main goal of this paper was to study the effect of ultrasonic treatment time on the mechanical properties of thermoplastic natural rubber(TPNR) reinforced with hybrid MWNTs-OMMT. The intercalation of TPNR enhancement into layers of clay by increasing the d-spacing was found using X-ray diffraction. The tensile properties of nanocomposites treated with ultrasonic increased when compared with untreated nanocomposites. The optimum ultrasonic treatment time was obtained at 3 h. The transmission electron microscope micrograph showed a combination of intercalated-exfoliated structure of the TPNR composites with organic clay and dispersion of MWNTs. The ultrasonic treatment can promote the dispersion of MWNTs-OMMT in TPNR and also improved the compatibility of hybrid filler and the TPNR matrix.
A thermoplastic elastomer (TPE) based nanocomposite with the same weight ratio of hybrid nanofillers composed of carbon nanotubes (CNTs) and montmorillonite nanoclay (DK4) was prepared using a melt blending technique with an internal mixer. The TPE composite was blended from polylactic acid (PLA), liquid natural rubber (LNR) as a compatibilizer and natural rubber (NR) in a volume ratio of 70:10:20, respectively. The weight ratio of CNTs and DK4 was 2.5 wt%. The prepared samples were exposed to gamma radiation at range of 0-250 kGy. After exposure to gamma radiation, the mechanical, thermo-mechanical, thermal and electrical conductivity properties of the composites were significantly higher than unirradiated TPE composites as the irradiation doses increased up to 150 kGy. Transmission electron microscopy (TEM) micrographs revealed the good distribution and interaction between the nano-fillers and the matrix in the prepared TPE hybrid nanocomposites. In summary, the findings from this work definite that gamma irradiation might be a viable treatment to improve the properties of TPE nanocomposite for electronic packaging applications.
Nanocellulose (CNF) has emerged as a promising alternative to synthetic petroleum-based polymers, but the conventional preparation process involves multiple tedious steps, heavily dependent on chemical input, and proves cost-inefficient. This study presented an, in situ ultrasound-assisted extraction using deep eutectic solvent (DES) based on choline chloride and oxalic acid for more facile production of CNF from raw durian husk fibers. FESEM analysis confirmed the successful extraction of web-like nanofibril structure with width size ranging from 18 to 26 nm. Chemical composition analysis and FTIR revealed the selective removal of lignin and hemicellulose from the raw fiber. As compared to post-ultrasound treatment, in situ ultrasound-assisted extraction consistently outperforms, yielding a higher CNF yield with finer fiber width and significantly reduced lignin content. Integrating this eco-friendly in situ ultrasonication-assisted one-pot extraction method with a 7.5 min interval yielded the highest CNF yield of 58.22 % with minimal lignin content. The superior delignification ability achieved through the proposed in situ ultrasound-assisted protocol surpasses the individual efficacy of DES and ultrasonication processes, neither of which yielded CNF in our experimental setup. This single-step fabrication process significantly reduces chemical usage and streamlines the production steps yielding web-structured CNF that is ideal for sustainable application in membrane and separator.
Neoterically, food packaging systems designed solely for prolonging shelf life or monitoring freshness could not fulfil the dynamic demands of consumers. In this current investigation, using the solvent casting method, a versatile halochromic indicator was created by integrating black currant anthocyanin and cinnamon essential oil-loaded Pickering emulsion into a starch/gelatin matrix. The resulting indicator film underwent scrutiny for its structural, pH-sensitive, antioxidant, and antimicrobial attributes. Unexpectedly, the amalgamation of anthocyanin and essential oil led to decreased antioxidant activity, dropping from 73.23 ± 2.17 to 28.87 ± 2.50 mg Trolox equivalent/g sample. Additionally, no discernible antimicrobial properties were detected in the composite film sample against both Staphylococcus aureus and Escherichia coli. Fourier transform infrared analyses unveiled robust intermolecular interactions among the film-forming components, providing insights into the observed antagonistic effect. The indicator film displayed distinctive colour changes corresponding to the fresh (greyish-brown), onset of decomposition (khaki), and spoiled (dark green) stages of the stored fish sample. This highlights its promising potential for providing real-time indications of food spoilage. These findings are important for the efficient design of composite films incorporating anthocyanins and essential oils. They serve as a guide towards their potential use as multifunctional packaging materials in the food industry.
While the economy is rapidly expanding in most emerging countries, issues coupled with a higher population has created foreseeable tension among food, water, and energy. It is crucial for more sustainable valorization of resources, for instance, nanocellulose, to address the core challenges in environmental sustainability. As the complexity of the system evolved, the timescale of project development has increased exponentially. However, research on the design and operation of integrated nanomaterials, along with energy supply, monitoring, and control infrastructure, has seriously lagged. The development cost of new materials can be significantly reduced by utilizing molecular simulation technology in the design of nanostructured materials. To realize its potential, nanocellulose, an amphiphilic biopolymer with the presence of rich -OH and -CH structural groups, was investigated via molecular dynamics simulation to reveal its full potential as Pickering emulsion stabilizer at the molecular level. This work has successfully quantified the Pickering stabilization mechanism profiles by nanocellulose, and the phenomenon could be visualized in three stages, namely the initial homogenous phase, rapid formation of micelles and coalescence, and lastly the thermodynamic equilibrium of the system. It was also observed that the high bead order was always coupled with a high volume of phase separation activities, through a coarse-grained model within 20,000 time steps. The outcome of this work would be helpful to provide an important perspective for the future design and development of nanocellulose-based emulsion products, which cater for food, cosmeceutical, and pharmaceutical industries.
In light of the adverse environmental impact of the R134a refrigerant, replacing it with a more environmentally friendly refrigerant has become imperative than ever. This study presents an experimental investigation into the utilization of R152a and R134a refrigerants in a vapor compression refrigeration system employing a variable displacement oil-free linear compressor. The potential for the replacement of R134a with R152a was examined based on energy, environmental, and economic performance analyses. The outcomes indicated that R152a exhibited a higher coefficient of performance (COP) in comparison to R134a under identical operating conditions. Specifically, when the pressure ratio was 2.0 and the piston stroke was 11 mm, R152a's COP was 13.0% higher than R134a. It was also discovered that reducing the operating stroke and increasing the pressure ratio could effectively lower CO2 emissions and total costs. Under the 2.0 pressure ratio and 9-mm piston stroke, R134a produced 1082.4 kg more CO2 emissions than R152a, representing a 209% increase. In addition, the R152a and R134a total cost was reduced by 8.3% with the 2.5 pressure ratio and 11-mm piston stroke. Notably, the results of the current study demonstrated that R152a outperformed R134a in energy consumption, environmental friendliness, and economy in oil-free linear compressor refrigeration systems. R152a used less electric power, generated fewer CO2 emissions, and naturally reduced predicted running costs in order to maintain the same COP.