Rapid Photothermal Responsive Conductive MXene Nanocomposite Hydrogels for Soft Manipulators and Sensitive Strain Sensors.

Stimulus-responsive hydrogels are of great significance in soft robotics, wearable electronic devices, and sensors. Near-infrared (NIR) light is considered an ideal stimulus as it can trigger the response behavior remotely and precisely. In this work, a smart flexible stimuli-responsive hydrogel with excellent photothermal property and decent conductivity are prepared by incorporating MXene nanosheets into the physically cross-linked poly(N-isopropyl acrylamide) hydrogel matrix. Because of outstanding photothermal effect and dispersion of MXene, the composite hydrogel exhibits rapid photothermal responsiveness and excellent photothermal stability under the NIR irradiation. Furthermore, the anisotropic bilayer hydrogel actuator shows fast and controllable light-driven bending behavior, which can be used as a light-controlled soft manipulator. Meanwhile, the hydrogel sensor exhibits cycling stability and good durability in detecting various deformation and real-time human activities. Therefore, the present study involving the fabrication of MXene nanocomposite hydrogels for potential applications in remotely controlled actuator and wearable electronic device provides a new method for the development of photothermal responsive conductive hydrogels.

Distribution-according-to-work: Enhancing solar vapor generation of photothermal sponge by using cellulose-based water storage platform.

Interfacial solar vapor generation (ISVG) has shown extraordinary promise in achieving high-efficiency water purification. However, the rapid water supply often leads to excessive water in the solar absorber, resulting in undesired heat loss and a decrease in evaporation rate. To tackle this issue, we developed a bio-based solar evaporator comprising cellulose-based water retention resin (CRR) and straw-derived photothermal sponge. CRR serves as an effective water storage platform with a high binding capacity for water molecules, preventing water from entering the absorber and reducing the water evaporation enthalpy. The water management of CRR confines the solar-to-vapor conversion to the interface between CRR and the photothermal sponge, thereby eliminating the adverse effects of excess water. Additionally, the ISVG process operates based on the principle of Distribution-according-to-work, meaning that the quantity of generated vapor depends on the evolution of the sponge structure. Optimal sponge configuration enables evaporation rates of 2.28 and 1.53 kg/m2/h under solar irradiation of 1.0 and 0.5 kW/m2, respectively. Additionally, the obtained evaporator is capable of producing 7.1 kg/m2/day of freshwater in outdoor experiment. This report proposes a novel approach to designing an ISVG device that incorporates effective water management strategy for achieving high-efficiency water purification in real-world scenarios.

A bilayer solar evaporator with all-in-one design for efficient seawater desalination.

Bilayer solar evaporator combines high photothermal conversion capacity and low heat loss, has become the new darling in interfacial solar steam generation (ISSG). However, the bilayer structure generally achieved by introducing a photothermal coating on the substrate is not conducive to long-term use due to the poor stability of coating. Herein, a fully biomass-based bilayer evaporator is all-in-one designed, using chitosan (CS) as building blocks and CS derived N, S - doped porous carbon (NSPC) as fillers via pre-freezing and freeze-drying. This facile method could realise the quantitative addition of photothermal materials and controllably regulate the structure of the bilayer evaporator, making the structural optimisation readily available. The optimised evaporator exhibits a remarkable evaporation rate of 2.51 kg m-2h-1. After 1000 times of pressing, it still maintains at 2.42 kg m-2h-1. Additionally, the evaporator displays outstanding long-lasting stability, excellent salt-resistant and degradability. More importantly, a solar desalination device is fabricated for harvesting freshwater outdoor. The daily water production per unit area (4.55 kg) meets the consumption of two adults. This work provides a controllable synthesis strategy of bilayer evaporators for handling global freshwater shortages.

Effect of carboxymethyl chitosan on the storage stability of frozen dough: State of water, protein structures and quality attributes.

Carboxymethyl chitosan (CMCh), an ampholetic chitosan derivative, has found broad applications in the food industry. However, its cryo-protective properties remained less explored compared to other viscous polysaccharides, such as carboxymethyl cellulose, carrageenan etc., which have been widely utilized as frozen food additives. In this study, we investigated the effect of CMCh addition to frozen dough in terms of water state, protein structure, and the textural properties of prepared frozen dumpling wrappers. Results indicated that CMCh restricted the water migration in dough and delayed protein deterioration during frozen storage. Specifically, the content of freezable water in dough was reduced and the water distribution became more uniform as reflected by DCS and LF-NMR analysis. CMCh also stabilized disulfide bond and secondary structures of the protein, leading to inhibition of dough rheology changes. Accordingly, the obtained frozen dumplings wrappers demonstrated decreased cracking rate and water loss, and improved textural properties. Moreover, CMCh with higher degree of carboxymethyl substitution (DS: 1.2, CMCh-B) exhibited better cryo-protective effects compared to CMCh of lower DS (DS: 0.8, CMCh-A). Our study provides novel insights and scientific basis for the development of ampholetic polysaccharides as high-performance food additives.

Characterization of Antennal Chemosensilla and Associated Chemosensory Genes in the Orange Spiny Whitefly, Aleurocanthus spiniferus (Quaintanca).

The insect chemosensory system plays an important role in many aspects of insects' behaviors necessary for their survival. Despite the complexity of this system, an increasing number of studies have begun to understand its structure and function in different insect species. Nonetheless, the chemosensory system in the orange spiny whitefly Aleurocanthus spiniferus, as one of the most destructive insect pests of citrus in tropical Asia, has not been investigated yet. In this study, the sensillum types, morphologies and distributions of the male and female antennae of A. spiniferus were characterized using scanning electron microscopy. In both sexes, six different sensilla types were observed: trichodea sensilla, chaetica sensilla, microtrichia sensilla, coeloconic sensilla, basiconic sensilla, and finger-like sensilla. Moreover, we identified a total of 48 chemosensory genes, including 5 odorant-binding proteins (OBPs), 12 chemosensory proteins (CSPs), 3 sensory neuron membrane proteins (SNMPs), 6 odorant receptors (ORs), 8 gustatory receptors (GRs), and 14 ionotropic receptors (IRs) using transcriptome data analysis. Tissue-specific transcriptome analysis of these genes showed predominantly expression in the head (including antennae), whereas CSPs were broadly expressed in both head (including the antennae) and body tissue of adult A. spiniferus. In addition, the expression profiling of selected chemosensory genes at different developmental stages was examined by quantitative real time-PCR which was mapped to the transcriptome. We found that the majority of these genes were highly expressed in adults, while AspiORco, AspiGR1, AspiGR2, and AspiIR4 genes were only detected in the pupal stage. Together, this study provides a basis for future chemosensory and genomic studies in A. spiniferus and closely related species. Furthermore, this study not only provides insights for further research on the molecular mechanisms of A. spiniferus-plant interactions but also provides extensive potential targets for pest control.