Introducing alien intercalations to sub-nanometer scale nanochannels is one desirable strategy to optimize the ion transportation of two-dimensional nanomaterial membranes for improving osmotic energy harvest (OEH). Diverse intercalating agents have been previously utilized to realize this goal in OEH, but with modest performance, complex operations, and physicochemical uncertainty gain. Here, we employ the self-exfoliation behavior of oxidative fragments (OFs) from graphene oxide basal plane under an alkaline environment to encapsulate detached OFs in nanochannels for breaking a trade-off between permeability and selectivity, boosting power density from 1.8 to 4.9 W m–2 with a cation selectivity of 0.9 and revealing a negligible decline in power density and trade-off during a long-term operation test (∼168 h). The strategy of membrane design, employing the intrinsically self-exfoliated OFs to decorate the nanochannels, provides an alternative and facile approach for ion separation, OEH, and other nano-fluidic applications.

Surface-enhanced Raman spectroscopy (SERS) has been identified as a fundamental surface-sensitive technique that boosts Raman scattering by adsorbing target molecules on specific surfaces. The application of SERS highly relies on the development of smart SERS substrates, and thus the fabrication of SERS substrates has been constantly improved. Herein, we investigate the impacts of different substrates on SERS technology including plasmonic metal nanoparticles, semiconductors, and hybrid systems in quantitative food safety and quality analysis. We first discuss the fundamentals, substrate designs, and applications of SERS. We then provide a critical review of the recent progress of SERS in its usage for screening and detecting chemical and biological contaminants including fungicides, herbicides, insecticides, hazardous colorants, and biohazards in food samples to assess the analytical capabilities of this technology. Finally, we investigate the future trends and provide practical techniques that could be used to fulfill the requirements for rapid analysis of food at a low cost.

Improving ring spinning efficiency and yarn quality is still challenging due to the sliding friction heat generated by the ring/traveler system, which limits the traveler speed and the yarn production rate. In this study, a finite element model based on the external heat source method was first used to explore the heat transfer process of the ring/traveler system. The reliability of the model was verified empirically. Subsequently, the validated model was used to analyze the effect of the model parameters on the temperature of the ring/traveler system. The results confirm that the high-temperature region of the ring and the traveler was concentrated on their contact area. More specifically the maximum temperature of the traveler was 159.2°C, which was almost three times the maximum temperature of the ring (62.6°C). In addition, smaller frictional coefficient and yarn tension, larger contact area and heat absorption rate, and better thermal conductivity can reduce the high local temperature of the ring/traveler system. Among them, yarn tension, friction coefficient, and heat absorption rate have a significant influence on the system temperature, especially for the small traveler. The developed model is also available for different fiber types and yarn counts which can be used for a comprehensive investigation of the heat transfer in ring spinning processes. The model and results of this study offer a theoretical basis for further optimizing the ring/traveler system and improving the productivity of ring spinning.

Cotton fabrics with superhydrophobic, antibacterial, UV protection, and photothermal properties were developed using Ag/PDMS coatings, and the role of coating formulations on the obtained functionalities was studied. Specific attention was paid to understanding the relationships between the fabrics’ superhydrophobicity and antibacterial activity against Escherichia coli (E. coli) bacteria. UV protection performance of Ag/PDMS coatings was thoroughly evaluated based on the variation of UV transmission rate through coated fabrics and photoinduced chemiluminescence spectra. Moreover, the effect of silver nanoparticles (Ag NPs) and PDMS on developing a photothermal effect on fabrics was discussed. It was found that the content of Ag NPs and PDMS played critical roles in determining the water contact angle (WCA) on modified fabrics. The largest WCA was 171.31°, which was durable even after numerous accelerated wash cycles and abrasions. Antibacterial activity of fabrics showed the positive effect of pure PDMS in bacterial growth inhibition. Moreover, it was found that the antibacterial performance was greatly affected by the content of Ag NPs loaded on fabrics rather than their superhydrophobic status. Moreover, increasing the content of Ag NPs boosted the UV protection level of fabrics, improved fabrics photostability, and reduced the UV transmission rate through fabrics. Testing the photothermal effect confirmed that the content of Ag NPs and PDMS both played prominent roles, where Ag acted as a photothermal agent and PDMS determined the NIR reflection rate from the coated surface. The modified fabrics were characterized using TGA, SEM, FTIR, and XRD techniques, and it was confirmed that using a higher amount of PDMS increased the amount of Ag NPs deposition on fabrics.

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