Facile Preparation of a Low-Cost Liquid Interlayer Material with Intelligent UV-NIR-Shielding Function for Smart Windows.

High-performance interlayer materials have garnered considerable interest owing to their low manufacturing costs and applicability in smart windows. In this study, a novel smart-window interlayer material capable of selective shielding against both near-infrared (NIR) and ultraviolet (UV) radiation is developed based on the light transmittance control mechanism. An excellent thermoresponsive liquid, denoted as CDs@TRL (viz., carbon quantum dots at thermal-responsive liquid), is synthesized by compositing biomass-based fluorescent carbon quantum dots (CDs) and poly(N-isopropylacrylamide) (pNIPAM) at natural ambient temperature and in an aqueous phase. Due to the characteristics of CDs and synergistic effect of hydrogen bonds, CDs@TRL exhibits a high specific heat capacity (4.41 kJ kg-1 K-1), large thermal storage capacity (264.6 kJ kg-1), and better UV-NIR-blocking properties, compared to pure pNIPAM, as well as improves the sensitivity of thermal response. When injected into a window as a liquid interlayer, CDs@TRL can intelligently adjust the light transmittance according to ambient light intensity to achieve an intelligent response. The shielding rate of a 10 mm-thick CDs@TRL composite liquid against UV radiation (200-400 nm) was more than 95% in an overcast environment with insufficient light and close to 100% in a well-lighted environment. In addition, CDs@TRL is a cost-effective material that can be prepared from a wide range of raw material sources using a simple preparation process and exhibits excellent mobility and recyclability. Because of these features, it is considered to be a promising candidate for developing energy-saving and climate-adapted smart windows.

An intelligent cooling material modified with carbon dots for evaporative cooling and UV absorption.

The emergence of cooling technology has brought about huge social benefits to society, but it is also accompanied by the serious problem of energy consumption. In countries close to the equator, intense solar radiation is accompanied by unbearable high temperatures and strong ultraviolet radiation. Therefore, we prepared a simple hydrogel with good evaporative cooling, which can work continuously and has good UV absorption, to solve the indoor cooling and UV radiation problems. Polyacrylamide (PAM) in the hydrogel provides a mechanically strong backbone, and polyethylene glycol (PEG) slows water loss and provides the hydrogel with the ability to reflect infrared light. Lithium bromide (LiBr) is a highly efficient water vapor absorbent, which can provide the hydrogel with water regeneration capability. Carbon dots (CDs) can provide excellent UV absorption for hydrogels, and CDs (4.28 kJ kg-1 K-1) have a higher specific heat capacity than water (4.20 kJ kg-1 K-1), which can store more heat for a better indoor cooling effect. The composite hydrogel has a good prospect of application in the windows of residential and high-rise buildings.

Recyclable, UV-Blocking, and Radiative Cooling Multifunctional Composite Membranes.

It is well known that UV radiation can cause human health problems and that energy consumption can lead to human survival problems. Here, we prepared a composite membrane that can block UV radiation as well as reduce energy consumption. Carbon dots (CDs) and acrylates were prepared from xylose and epoxidized soybean oil as biomass feedstocks, respectively, and the composite membrane was prepared by a self-assembly strategy. The first layer of the membrane is composed of CDs and epoxy resin. Its main function is not only to weaken UV rays and the aggregation-induced quenching effect of CDs but also to reduce the absorption of UV rays by the second layer of the membrane. The second layer consists of barium sulfate (BaSO4) and acrylate. Compared to TiO2 (3.2 eV), BaSO4 (∼6 eV) has a higher electronic band gap, which reduces the absorption of UV light by the membrane. The composite membrane exhibits excellent UV-blocking and radiative cooling performance, shielding 99% of UV rays. In addition, the membrane can reduce 4.4 °C in radiative cooling tests, achieving a good cooling effect. Finally, the recyclability of the BaSO4/acrylate membrane is discussed, and 95% recovery rate provides sustainable utilization of the membrane. The composite membrane is expected to be popularized and used in low latitudes and areas with high temperature and high UV radiation near the equator.

An All-In-One Multifunctional Touch Sensor with Carbon-Based Gradient Resistance Elements.

HIGHLIGHTS: Carbon-based gradient resistance element structure is proposed for the construction of multifunctional touch sensor, which will promote wide detection and recognition range of multiple mechanical stimulations. Multifunctional touch sensor with gradient resistance element and two electrodes is demonstrated to eliminate signals crosstalk and prevent interference during position sensing for human-machine interactions. Biological sensing interface based on a deep-learning-assisted all-in-one multipoint touch sensor enables users to efficiently interact with virtual world. Human-machine interactions using deep-learning methods are important in the research of virtual reality, augmented reality, and metaverse. Such research remains challenging as current interactive sensing interfaces for single-point or multipoint touch input are trapped by massive crossover electrodes, signal crosstalk, propagation delay, and demanding configuration requirements. Here, an all-in-one multipoint touch sensor (AIOM touch sensor) with only two electrodes is reported. The AIOM touch sensor is efficiently constructed by gradient resistance elements, which can highly adapt to diverse application-dependent configurations. Combined with deep learning method, the AIOM touch sensor can be utilized to recognize, learn, and memorize human-machine interactions. A biometric verification system is built based on the AIOM touch sensor, which achieves a high identification accuracy of over 98% and offers a promising hybrid cyber security against password leaking. Diversiform human-machine interactions, including freely playing piano music and programmatically controlling a drone, demonstrate the high stability, rapid response time, and excellent spatiotemporally dynamic resolution of the AIOM touch sensor, which will promote significant development of interactive sensing interfaces between fingertips and virtual objects.

The effect of promoting hydrogen bond aggregation based on PEMTC on the mechanical properties and shape memory function of polyurethane elastomers.

In this work, small molecule diols named PEMTC were synthesized from isophorone diisocyanate, N-(2-hydroxyethyl)acrylamide and trimethylolpropane by a semi-directional method. PEMTC (2-(prop-2-enamido)ethyl N-{3-[({[2-ethyl-3-hydroxy-2(hydroxymethyl)propoxy]carbonyl}amino)methyl]-3,5,5-trimethylcyclohexyl}carbamate) contains hydrogen bond active site and light-initiated C=C. We introduced it as a branch chain block into poly(ε-caprolactone) (PCL). By feeding and monitoring the reaction process, we synthesized a large number of polyurethane elastomers, hydrogen bonds PCL-based elastomer (HPE), which contain a large number of dynamic hydrogen bonds. Under UV irradiation, PEMTC can make HPE molecules aggregate and cross-link, improve the degree of internal hydrogen bonding interaction of HPE materials and endow HPE materials with good elasticity, toughness, heat resistance and shape memory ability. After 270 nm UV irradiation, the elongation at break of HPE materials decreased from 607.14-1463.95% to 426.60-610.36%, but the strength at break of HPE materials increased from 3.36-13.52 to 10.28-41.52 MPa, and the toughness increased from 16.36-129.71 to 40.48-172.22 MJ m-3. In addition, the highest shape fixation rate of HPE after UV irradiation was 98.0%, and the recovery rate was 93.7%.

Lightweight MWCNT/hollow mesoporous carbon/WPU composite material with excellent electromagnetic shielding performance.

With the rapid increase of intelligent communication equipment, electromagnetic pollution is becoming more and more serious, and the research and application of high-performance electromagnetic shielding materials have attracted great attention from the academic and engineering circles. Traditional metal-based electromagnetic shielding materials have high reflection loss, high density, and are difficult to process. Polymer-based materials with carbon materials as fillers have the advantages of flexibility, light weight, corrosion resistance and low processing costs. They have become the most important materials in the field of electromagnetic shielding in recent years. However, the conductivity of conductive polymer materials is not high. Therefore, improving the electromagnetic shielding performance and the proportion of absorption loss under low density conditions have become key issues for polymer-based electromagnetic shielding materials. MWCNT/MCHMs/WPU composites were prepared by a solution mixing method, with 20 wt%, 40 wt%, 60 wt% MWCNTs and 40 wt% MWCNT/10 wt% MCHMs as fillers. By comparing the effects of different MWCNT content and MCHMs on the dielectric properties, electromagnetic shielding properties and mechanical properties of the MWCNT/MCHMs/WPU composites, the relationship between the structure and properties of the composites has been explored. The 0.6 mm WPU/60 wt% MWCNT composite has an electrical conductivity of 95.4 S m-1 and an electromagnetic shielding effectiveness of 40 dB in the X band. Adding 10 wt% MCHMs to the WPU/40 wt% MWCNT composite material can significantly improve the composite. The δ of the material increased from 51.2 S m-1 to 55.4 S m-1, and the SE increased from 30 dB to 33 dB. The research results show that the increase in MWCNT content and MCHMs is beneficial to improving the electrical conductivity and electromagnetic shielding performance of the composite materials.

Rationally designed structure of mesoporous carbon hollow microspheres to acquire excellent microwave absorption performance.

In this study, we used a novel and facile hard-template etching method to manufacture mesoporous carbon hollow microspheres (MCHMs). We prove that the dielectric ability and microwave absorption of MCHMs can be adjusted by structural characteristics. When the average particle size of MCHMs is 452 nm, the paraffin composite material mixed with 10 wt% MCHMs can achieve a maximum reflection loss value of -51 dB with a thickness of 4.0 mm at 7.59 GHz. When the average particle size of MCHMs is 425 nm, the effective absorption bandwidth of the paraffin composite material mixed with 10 wt% MCHMs can achieve a broad bandwidth of 7.14 GHz with a thickness of 2.5 mm. Compared with other microwave absorbers, MCHMs possess high microwave absorption capacity and broad microwave absorption bandwidth with as low as a 10 wt% filler ratio. This excellent microwave absorption performance is due to the internal cavity and the mesoporous shell of MCHMs. By rationally designing the structure of MCHMs, excellent microwave absorption performance can be acquired. Meanwhile, this design concept based on a rational design of spherical structure can be extended to other spherical absorbers.

[Estradiol enhances the proliferation and migration of Ishikawa cells by promotion of angiogenesis induced by activation of NF-κB via AKT pathway].

OBJECTIVE: The aim of this study was to explore whether estradiol induces the expression of VEGF and bFGF in the endometrial cancer Ishikawa cells by activation of NF-κB via AKT pathway, and its effect on cell proliferation. METHODS: Western blot was used to detect the AKT protein expression in Ishikawa cells after stimulation with estradiol, and the effect of AKT inhibitor or ER inhibitor on the activation of AKT. TransAM kit was used to detect the NF-κB p65 activity. qPCR and Western blot were used to detect the expression of VEGF and bFGF mRNA and proteins in the Ishikawa cells after estradiol treatment (E2 group), and pretreated with AKT inhibitor (AKT group) or ER inhibitor (ER group) or NF-κB inhibitor (NF-κB group), following the estradiol treatment. Flow cytometry and CFSE (carboxyfluorescein diacetate, succinimidyl ester) staining were used to examine the cell proliferation. Transwell was used to detect the migration ability of Ishikawa cells. RESULTS: Expression of p-AKT protein in the Ishikawa cells was markedly higher than that in the control group (P < 0.05). Expressions of p-AKT protein in the AKT and ER groups were significantly decreased than that in the E2 group (P < 0.05). The NF-κB activity was highest after stimulation with 1×10(-6) mol/L estradiol for 30 min to 1 h. AKT inhibitor significantly reduced the NF-κB activity (P < 0.05). The expressions of VEGF and bFGF mRNA and proteins in the E2 group were significantly increased than that in the control group (P < 0.05), and their expression in the AKT, ER and NF-κB groups were significantly decreased than that in the E2 group (P < 0.05). The proliferation and migration abilities of the Ishikawa cells were significantly increased after estradiol stimulation. CONCLUSIONS: Estradiol induces the production of VEGF and bFGF through activating NF-κB via AKT pathway, and enhances the proliferation and migration ability of cancer cells.