Hybrid Filler with Nanoparticles Grown in Situ on the Surface for the Modification of Thermal Conductive and Insulating Silicone Rubber

Insulating materials with high thermal conductivity have become the key to solving the internal heat problem of electronic components. In this study, two fillers were prepared by the in situ generation method. The uniform distribution of silicon dioxide (SiO2) nanoparticles and silver (Ag) nanoparticles on the surface of graphene oxide (GO) and silicon carbide (SiC) was proved by characterization methods such as micromorphology (TEM and SEM) and elemental analysis (XPS), respectively. The fillers above prepared were then added to silicone rubber (SR) to improve its thermal conductivity. SiO2 nanoparticles attached to the GO surface were compatible with the SR matrix, so the thermal resistance of the interface between the GO and the matrix was reduced. The thermal conductivity of Ag nanoparticles generated on the SiC surface was significantly better than that of SiC whiskers. Besides, the composite filler was more conducive to the formation of a heat conduction path, so the thermal conductivity of silicone rubber was improved. In addition, the composite SR maintained pleasing electrical insulating properties, and the volume resistivity of all samples was above 1013 Ω·cm. The prepared composite filler and composite SR provide ideas for developing high-performance thermally conductive and insulating polymers

Wettability-Patterned Meshes for Efficient Fog Collection Enabled by Polymer-Assisted Laser Sintering

Water collection from fog has been considered as a meaningful strategy to alleviate the scarcity of fresh water in some arid and semi-arid lands. Due to the specific wettability pattern on the back, Stenocara beetles show amazing capability for water capture from fog. Various biomimetic flat surfaces with wettability have been reported in the last decade. However, it is still a great challenge to accurately construct a patterned surface on a mesh, which is the common material in the practical application of fog collection. Herein, a facile and easy-to-operate strategy for surface modification on a stainless-steel (SS) mesh based on polymer-assisted laser sintering has been developed. A certain polymer film can be chosen to obtain different wettabilities because of the elemental composition and microstructure after laser sintering. Laser sintering following pre-design contributed to accurate control of the pattern geometry, size, and site. A bio-inspired pattern mesh with isolated triangular superhydrophobic regions and hydrophilic channels was fabricated for water collection from fog flow. Due to the good balance of water droplet capture, growth, and removal, the rationally designed SS mesh showed a satisfactory collection rate as high as 177.65 mg cm–2 h–1, which was a nearly 16-fold increase compared to that of the pristine SS mesh. The obtained mesh also showed high stability not only in long-term applications but also in several cycles of regeneration. Based on the outstanding performance of fog water collection, the patterned SS mesh could be of great value in practical applications. Furthermore, the polymer-assisted laser sintering strategy for surface modification on mesh could potentially be applied in various fields for high efficiency and scalability

Preparation of Insoluble Bis(2-bromoacetyl)biphenyl via a Photoultrasound Enhanced Continuous Flow Reaction

In continuous multiphase flow photochemical reactions, the generation of insoluble materials can significantly reduce the efficiency of material and light energy transfer between interfaces due to numerous interfaces within the hybrid system. The problem of solids blocking pipelines further compounds this issue. This study presents the design and construction of an optical-ultrasonic coupled continuous flow reactor to synthesize the insoluble α-bromoketone (4,4′-bis­(2-bromoacetyl)­biphenyl) is continuously produced in situ for synthesis, eliminating the need for large quantities of toxic bromine. A flowing cooling medium enhanced the ultrasound power transfer and eliminated the thermal effects of the ultrasound and light sources under TR = 2.1 min, T = 20 °C, and a flow cooling medium thickness of 1.5 cm. The reactants were converted to 92.4% and yielded up to 90.2%, significantly better than the batch reactor results. The experimental results show that the product particles are reduced considerably under ultrasound, eliminating the blockage. Free radical capture experiments investigated the stepwise bromination mechanism, kinetic parameters were calculated, and the reaction rate expressions derived from the basic steps were consistent with the kinetic model. These findings provide valuable insights into the reaction process, contributing to a more comprehensive understanding

Copper-Based Integral Catalytic Impeller for the Rapid Catalytic Reduction of 4‑Nitrophenol

The integral catalytic impeller can simultaneously improve reaction efficiency and avoid the problem of catalyst separation, which has great potential in applying heterogeneous catalysis. This paper introduced a strategy of combining electroless copper plating with 3D printing technology to construct a pluggable copper-based integral catalytic agitating impeller (Cu-ICAI) and applied it to the catalytic reduction of 4-nitrophenol (4-NP). The obtained Cu-ICAI exhibits very excellent catalytic activity. The 4-NP conversion rate reaches almost 100% within 90 s. Furthermore, the Cu-ICAI can be easily pulled out from the reactor to be repeatedly used more than 15 times with high performance. Energy-dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy characterizations show that the catalyst obtained by electroless copper plating is a ternary Cu-Cu2O-CuO composite catalyst, which is conducive to the electron transfer process. This low-cost, facile, and versatile strategy, combining electroless plating and 3D printing, may provide a new idea for the preparation of the integral impeller with other metal catalytic activities

Improved Water Collection from Short-Term Fog on a Patterned Surface with Interconnected Microchannels

Fog harvesting is considered a promising freshwater collection strategy for overcoming water scarcity, because of its environmental friendliness and strong sustainability. Typically, fogging occurs briefly at night and in the early morning in most arid and semiarid regions. However, studies on water collection from short-term fog are scarce. Herein, we developed a patterned surface with highly hydrophilic interconnected microchannels on a superhydrophobic surface to improve droplet convergence driven by the Young–Laplace pressure difference. With a rationally designed surface structure, the optimized water collection rate from mild fog could reach up to 67.31 g m–2 h–1 (6.731 mg cm–2 h–1) in 6 h; this value was over 130% higher than that observed on the pristine surface. The patterned surface with interconnected microchannels significantly shortened the startup time, which was counted from the fog contact to the first droplet falling from the fog-harvesting surface. The patterned surface was also facilely prepared via a controllable strategy combining laser ablation and chemical vapor deposition. The results obtained in outdoor environments indicate that the rationally designed surface has the potential for short-term fog harvesting. This work can be considered as a meaningful attempt to address the practical issues encountered in fog-harvesting research

Additional file 1 of Organising a juvenile ratio monitoring programme for 10 key waterbird species in the Yangtze River floodplain: analysis and proposals

Additional file 1: Table S1. The fieldwork that generated the data analysed here came from 17 lakes and 501 points in the YRF from 2016 to 2019. Table S2. Photographic information relating to the 10 waterbird species involved in the juvenile ratio survey of Yangtze River, illustrating the salient plumage differences and other features that are characteristic of adult and young birds of all species (Brazil 2009). Table S3. Autumn and spring migration schedules of eight large waterbird species in China based on published tracking studies. Table S4. The 1% biogeographical flyway population levels for each of the 10 large-bodied waterbirds wintering in the Yangtze River Floodplain analysed here. Table S5. The sample sizes and juvenile ratio from each of the 10 large waterbird species surveyed in each year from 2016 to 2019 (see “Methods” – Data analysis). Table S6. The percentage of each large waterbird species counted in a given year at six sites of major flyway importance in the Yangtze River Floodplain. Table S7. The error rate between predicted juvenile ratio and YRF sampled juvenile ratio of 10 large-bodied waterbirds in Yangtze River Floodplain from 2016 to 2019. Table S8. The error rate between predicted juvenile ratio and Yangtze River Floodplain sampled juvenile ratio of 10 large-bodied waterbird species in sites of major flyway importance from 2016 to 2019. Table S9. The error rate between sampled juvenile ratio in November and sampled juvenile ratio in December of 10 large-bodied waterbirds in the same lake from 2016 to 2019. Table S10. The theoretical error, real error and T2_Weight results of 10 large-bodied waterbird species in the Yangtze River Floodplain based on statistical independence test analysis. Table S11. The sqrt_sum_Weight results of 10 large-bodied waterbird in YRF from 2016 to 2019 based on statistical independence test analysis. Table S12. Cross-comparison table showing juvenile ratios generated (j/N, where j is the number of juveniles in sample N) from each annual sample (sample size N) for each of the 10 large-bodied waterbird species in each year, 2016 to 2019

Structural and Morphological Evolution upon Heating of Quenched Polyamide 1012

In this study, the crystal form transition and semicrystalline morphology evolution of quenched polyamide 1012 (PA1012) during heating were investigated. Quenched PA1012 displayed a pseudohexagonal γ′ form at room temperature, in which the methylene segments adopted a trans conformation, the methylene group directly attached to the amide group was twisted, and the hydrogen bonding pointed in all directions. During heating, the γ′ form gradually transformed into the γ form as the trans methylene sequences that are away from the amide group further twisted, and the dihedral angle between the amide and methylene plane exhibited a narrow distribution. The transition onset temperature was near the glass transition temperature of quenched PA1012. The semicrystalline morphology of quenched PA1012 was characterized as a loose network consisting of a disordered arrangement of thin lamellae with poorly defined boundaries. As the annealing temperature increased, the lamellae became more perfect and thicker, while the morphological type remained the same