Silane Coupling Agent KH550 Research Articles

Research on silk fibroin composite materials for wet environment applications

Silk fibroin material has good mechanical properties and excellent biocompatibility as a natural biomaterial with broad application prospects. However, by applying regenerated silk fibroin in biomaterials with high mechanical strength requirements, such as bone materials, there are problems, such as insufficient mechanical properties and a significant decline in mechanical properties in the wet state. In this report, a silk fibroin composite that maintains high strength in the wet state was prepared by adding nano-SiO2 as a nano-strengthening filler to the silk protein material and employing an epoxy-based silane coupling agent KH560 as an interfacial reinforcing agent. The results showed that the dry compressive strength of the composite material was substantially increased compared with that of the pure silk protein material; the wet compressive strength was significantly increased compared with that of the pure silk fibroin material, and the decrease of the mechanical properties in the wet state was low. The cytotoxicity test results of the composites showed that the materials were not cytotoxic. Rat bone marrow mesenchymal stem cells were cultured on the surface of the composites, and the results indicated that the composites could support the proliferation of bone marrow mesenchymal stem cells. The silk fibroin nanocomposites developed in this work can be applied as bone repair materials.

Enhanced mechanical, thermal, water and UV aging resistance properties of bamboo fiber/HDPE composites through silane coupling agent modified nano-SiO2-TiO2

Nano-TiO2 is widely employed to enhance the properties of plant fiber reinforced thermoplastic polymer composites due to its chemical inertness, anti-aging, and anti-bacterial properties. However, the enhancement of bamboo fiber/high-density polyethylene (BF/HDPE) composites is limited by the high photocatalytic activity of nano-TiO2 and its poor compatibility with the BF/HDPE matrix. This study employs an organic-inorganic co-modification to prepare BF/HDPE composites reinforced with silane coupling agent KH550 modified nano-SiO2 coated nano-TiO2 (KH550/SiO2-TiO2) by spray coating and melt mixing methods, and the properties of the composites were tested and characterized. The effects of KH550 and KH550/SiO2-TiO2 content on the properties of modified BF/HDPE composites, including mechanical properties, water absorption, thickness swelling rate, water contact angle, thermal stability, and UV aging resistance，which were characterized using methods of mechanical tests, FTIR, UV-Vis, XPS and SEM, both before and after modification. The results indicate that KH550 effectively improves the agglomeration phenomenon and enhances the dispersibility of nano-SiO2-TiO2 in the BF/HDPE composites. The optimal thermal stability is achieved when the BF/HDPE composites modified with a 5 wt% KH550/SiO2-TiO2, while BF/HDPE composites modified with a 3 wt% KH550/SiO2-TiO2 exhibit the better mechanical properties, water resistance, and UV aging resistance compared to other contents. Flexural strength and modulus of KH550/SiO2-TiO2 modified BF/HDPE composites increased by 18.71 % and 17.92 %, tensile strength and modulus increased by 7.74 % and 21.92 %, respectively. The 480-hour water absorption and thickness swelling rate decreased by 18.68 % and 20.73 %, respectively, and the contact angle increased by 19.17°; better thermal stability and color stability was observed. The spray coating method was more effective in improving the properties of the modified BF/HDPE composites than the melt mixing method. Comprehensive analysis indicates that the mechanical properties, water resistance, thermal stability, and UV aging resistance of the BF/HDPE composites reinforced with 3 wt% KH550/SiO2-TiO2 prepared by the spray coating method are significantly enhanced.

Silane modified Cr2O3/polyimide nanocomposite films with excellent surface insulation performance for space applications

The exploration of deep space significantly increases the probability of spacecraft failures due to surface electrostatic discharge, which imposes higher vacuum insulation protection requirements on polyimide (PI), the external insulation material of spacecrafts. To address this challenge, this study proposes using silane coupling agent KH550 for organic grafting treatment of Cr2O3nanoparticles, which are then used to dope and modify PI to enhance the vacuum surface insulation of PI films. The KH550 grafting improves the interface strength between the fillers and the matrix, allowing the fillers to be uniformly dispersed in the matrix. Compared to pure PI films, the prepared PI-Cr2O3@KH550 composite films exhibit significantly enhanced vacuum surface flashover voltage, improved surface/volume resistivity, and dielectric properties. The results demonstrate that PI composite films with 0.8% by mass of Cr2O3@KH550 show the most notable performance improvement, with the DC flashover voltage and impulse flashover voltage in vacuum increasing by 20.7% and 27.8%, respectively. The doping of chromium oxide nanoparticles introduces more deep traps into the PI films and reduce the surface resistivity. The higher deep trap density inhibits charge migration, thereby alleviating secondary electron emission and surface electric field distortion. Simultaneously, the lower surface resistivity facilitates dissipating surface charges and improves the surface insulation. These findings are of significant reference value for promoting the enhancement of aerospace insulation performance.

Mechanical Properties of Ultra-High-Performance Concrete with Amorphous Alloy Fiber: Surface Modification by Silane Coupling Agent KH-550.

Amorphous alloy fiber has the advantages of high tensile strength and high corrosion resistance compared with steel fiber, but its interfacial bonding with cement matrix is poor and requires surface modification treatment. In this study, the surface modification of amorphous alloy fiber was carried out by using silane coupling agent KH-550 solution, and its effect on the mechanical properties of ultra-high-performance concrete was investigated. The results showed that the amorphous alloy fibers modified with 15% concentration silane coupling agent KH-550 solution can effectively improve the mechanical properties of the ultra-high-performance concrete, where the interfacial bond strength with the cement matrix reached 3.29 MPa and the roughness reached 3.85. The compressive strength, flexural strength, tensile strength, and peak stress of the ultra-high-performance concrete mixed with modified amorphous alloy fibers could reach up to 133.6 MPa, 25.5 MPa, 8.32 MPa, and 114.26 MPa, respectively, which were 2.9%, 6.3%, 10.9%, and 4.3% higher than those of the ultra-high-performance concrete with unmodified amorphous alloy fibers. As the surface of the fiber was modified, its properties changed and the bonding effect with the cement matrix was better, which in turn improved the mechanical properties of the ultra-high-performance concrete.

High-Strength Controllable Resin Plugging Agent and Its Performance Evaluation for Fractured Formation.

Lost circulation is a common and complicated situation in drilling engineering. Serious lost circulation may lead to pressure drop in the well, affect normal drilling operations, and even cause wellbore instability, formation fluid flooding into the wellbore, and blowout. Therefore, appropriate preventive and treatment measures need to be taken to ensure the safe and smooth operation of drilling operations. So, it is necessary to conduct in-depth research on the development and performance of the plugging materials. In this study, urea formaldehyde resin with high temperature resistance and strength was used as the main raw material, and the curing conditions were optimized and adjusted by adding a variety of additives. The curing time, compressive strength, temperature resistance, and other key performance indexes of the resin plugging agent were studied, and a resin plugging agent system with excellent plugging performance was prepared. The formula is as follows: 25% urea formaldehyde resin +1% betaine +1% silane coupling agent KH-570 + 3% ammonium chloride +1% hexamethylenetetramine +1% sodium carboxymethyl cellulose. The optimal curing temperature is between 60 and 80 °C, with a controllable curing time of 1-3 h. Experimental studies examined the rheological and curing properties of the resin plugging agent system. The results showed that the viscosity of the high-strength curable resin system before curing remained stable with increasing shear rates. Additionally, the storage modulus and loss modulus of the resin solutions increased with shear stress, with the loss modulus being greater than the storage modulus, indicating a viscous fluid. The study also investigated the effect of different salt ion concentrations on the curing effect of the resin plugging system. The results showed that formation water containing Na+ at concentrations between 500 mg/L and 10,000 mg/L increased the resin's curing strength and reduced curing time. However, excessively high concentrations at lower temperatures reduced the curing strength. Formation water containing Ca2+ increased the curing time of the resin plugging system and significantly impacted the curing strength, reducing it to some extent. Moreover, the high-strength curable resin plugging agent system can effectively stay in various fracture types (parallel, wedge-shaped) and different fracture sizes, forming a high-strength consolidation under certain temperature conditions for effective plugging. In wedge-shaped fractures with a width of 10 mm, the breakthrough pressure of the high-strength curable resin plugging agent system reached 8.1 MPa. As the fracture width decreases, the breakthrough pressure increases, reaching 9.98 MPa in wedge-shaped fractures with an outlet fracture width of 3 mm, forming a high-strength plugging layer. This research provides new ideas and methods for solving drilling fluid loss in fractured loss zones and has certain application and promotion value.

Effect of seawater corrosion on the mechanical properties of basalt fiber reinforced polymer composites modified by silane coupling agent KH560 and carboxylated carbon nanotubes

Basalt fiber reinforced composite (BFRP) has been widely used in various engineering fields, while the corrosion resistance of BFRP in harsh environments needs to be improved. In this work, the effects of seawater corrosion on mechanical properties of silane coupling agent (KH560) and carboxylated carbon nanotubes (CNTs) modified basalt fiber reinforced epoxy resin composites (BF/EP) were studied by simulating seawater corrosion under different conditions. The results showed that with the increase in corrosion time and temperature, the flexural performance and interlaminar shear strength (ILSS) of the composite material significantly decreased. Under the same corrosion conditions, the modified basalt fiber composite has better corrosion resistance to seawater than the untreated one due to an enhanced "soft-rigid" multi-scale stress transfer region between the BF and resin matrix. The flexural strength, flexural modulus and ILSS of modified basalt fiber composites decreased by 17.7 %, 12.2 % and 11.3 %, respectively, after 7 weeks of seawater corrosion at 60 °C, while that of untreated basalt fiber composites decreased by 28.2 %, 20.4 % and 19.7 %, respectively. In addition, the corrosion of distilled water on basalt fiber composites was also studied. Similarly, the modified basalt fiber composites showed better corrosion resistance to distilled water compared to the untreated basalt fiber composites. The research shows that the synergistic modification of KH560 and CNTs can effectively improve the corrosion resistance of BF/EP. This work is significant for promoting the development of BFRP and its application in marine environment.

Research on the synergistic flame retardation of epoxy resin through surface-modified aluminum diethylphosphinate in conjunction with DOPO and CFA

Surface modification of aluminum diethylphosphinate (ADP) was successfully achieved through the utilization of silane coupling agent KH-560. Simultaneously, the modified aluminum diethylphosphinate (K-ADP) served as the primary flame retardant, with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as the phosphorus-based flame retardant and charring‐forming agent (CFA) as the nitrogen-based synergistic flame retardant. This approach was employed to investigate the flame-retardant modification of epoxy resin. The optimal dosage of the surface modifier was investigated through moisture absorption test and viscosity measurements. Synergistic flame-retardant interactions among K-ADP, DOPO, and CFA were examined using techniques such as cone calorimetry test, thermogravimetric analysis, and residual char infrared analysis. The results indicated that the optimal dosage of KH-560 is 5%, resulting in a significant reduction in moisture absorption to 0.195%. At 80 °C, the addition of K-ADP leaded to only a 22.7% increase in system viscosity, demonstrating a notable viscosity reduction effect. When the addition of K-ADP is 14%, the Limiting Oxygen Index (LOI) value reached 30.5%, achieving a V-0 rating. Moreover, by maintaining the total addition at 14% and introducing DOPO and CFA, it is evident that most of samples meet UL-94 V-0 rating, with the LOI elevated to 32.2%. CCT results indicated a significant decrease in both average heat release rate and total smoke production, reduced by 24.1% and 7.0%, respectively. This notably enhanced the flame-retardant and smoke-suppressant properties of the EP composite material. The addition of K-ADP, DOPO, and CFA improved the mechanical performance of the EP composite material, surpassing the effectiveness of adding ADP individually.

Investigating the impact of silane on different surface modified stainless steel ultra-thin strips and the bonding interface of stainless-steel bonded with epoxy

The silane coupling agent is extensively utilized to improve the bonding strength between the stainless steel (SS) ultra-thin strip and the epoxy resin. Along these lines, the response of SS strips with different mild surface modifications to silane coupling agent was systematically investigated. It was found that the HCl etching and anodizing-thermally treating sample (EAT-SS) exhibited a relatively optimal response to the KH550 silane coupling agent. This effect was attributed to the increased surface roughness and abundant micro/nano scale porous structure. The shear strength of the EAT-SS/epoxy specimen increased from 6.05 MPa to 16.04 MPa due to the improved interlock effect induced by the coexistence of the micro and nano structures, further increased to 20.36 MPa after the incorporation of the KH550 coating with a 4 wt% mass fraction. This improvement can be attributed to the increased thickness of the bonding interface and dual introduction of mechanical interlocking and chemical bonding effects after the application of the KH550 coating. Besides, the enhancement effect of the KH550 coating was stronger than that of KH560, which can be ascribed to the chemical reaction between the amino group in the former and the epoxy group in epoxy resin.

Enhanced mechanical properties of poly(butylene succinate)/silk sericin composite monofilaments with silane coupling agent KH570

Biodegradable Poly (butylene succinate) (PBS) composites with natural polymers have been widely developed, the compatibility of PBS and natural polymers is often the first consideration in terms of performance. In this work, PBS/silk sericin composite monofilaments (content of silk sericin is 6 wt%) with γ-methacryloxypropyltrimethoxysilane (KH570) as the coupling agent were fabricated by reactive melt-mixing, spinning, and stretching. The effect of KH570 content (1–3 wt%) on the morphology, mechanical property and biodegradation was studied. The reaction between the hydroxyl groups of silk sericin and -Si-OH of KH570 was analyzed by Fourier transform infrared spectroscopy. The cross-section morphology of the monofilaments obtained from SEM and EDS images indicates that the dispersion of silk sericin is improved with the increase of KH570 content. Compared with unmodified composite monofilaments, the composite monofilament with 2 wt% KH 570 shows the best mechanical performance (102% and 80% improvement in tensile strength and elongation at break respectively). The incorporation of silk sericin, which possesses skin-friendly properties, imparts composite monofilaments with advantages in the fields of clothing, headgear, shoe uppers and other related applications. Otherwise, the silk sericin can enhance the biodegradability velocity of PBS/silk sericin composite monofilaments. And the weight loss of the composite monofilaments buried in soil can be adjusted by the synergistic effect of silk sericin and KH570.

Enhancing interface compatibility in high-filled coal gangue/polyethylene composites through silane coupling agent-mediated interface modification

This study investigates the profound impact of surface modification using the silane coupling agent KH550 on Coal Gangue (CG)-Polyethylene (PE) composites. The aim was to enhance the properties of composites while addressing waste material accumulation concerns. Comprehensive analyses elucidated the mechanism of interface formation and the subsequent influence on composite properties. Surface modification of CG with KH550 demonstrated pronounced effects on physical, mechanical, and thermal properties of the resulting composites. Notably, the coupling agent facilitated covalent bonding with CG, preventing particle agglomeration and enhancing dispersion stability. The introduction of KH550 contributed to heterogeneous nucleation, augmenting composite crystallinity and interfacial bonding with the resin, thereby improving overall compatibility. Mechanical tests revealed substantial enhancements in tensile and bending strengths with optimal KH550 content. However, excess KH550 led to diminishing returns, highlighting the critical balance required for effective modification. Thermal stability assessments demonstrated improved properties owing to KH550 modification, validating its role in safeguarding the composite matrix from thermal degradation. Microstructural analyses, including SEM, FTIR, DSC, and XRD, provided insights into the interface morphology, chemical composition, crystalline behavior, and structure of the composites. The SEM micrographs elucidated a progressive shift from clear interface boundaries to more homogenously blended states with increasing KH550 content, indicative of enhanced interaction between CG and PE. This comprehensive study demonstrates that KH550 modification offers a strategic approach to optimize CG-PE composites, showcasing potential applications in the automotive and construction industries. Those findings underscore the significance of surface modification techniques in enhancing composite properties and utilizing waste resources efficiently.

VO2 nano-rod coated mica composite pearlescent pigment for temperature control packaging

A temperature control mica/VO2 functional pearlescent pigment was designed for the packaging industry. Firstly, a layer of VO2 nanorod film was coated on the surface of flake mica powder by hydrothermal method. Then, the surface of pure mica was modified by silane coupling agent KH-570 and sandwiched between inorganic powders to strengthen the combination. Secondly, the mica/VO2 composite pearlescent powder with gray-green pearlescent effect were successfully obtained by thermal annealing. The crystal structure of the VO2 coating and the chemical valence state of vanadium were verified by X-ray diffraction and X-ray photoelectron spectroscopy. Finally, powders were mixed with polyurethane resin to obtain a functional film. The infrared transmittance of film at 28 °C and 70 °C showed that the composite film with mica content of 3 g had greater temperature control properties, and the difference between high and low temperature transmittance was about 16%. Most importantly, the shiny decorative effect of pearlescent pigment can be still be maintained after being endowed with temperature control property. This work proposes the preparation of functional mica/VO2 composite with pearlescent effect and temperature control property.

TiO2/EP superhydrophobic composite coating with excellent mechanical and chemical stability

Superhydrophobic coatings have great influence in various applications because of their excellent hydrophobic properties. The focus of current research is to develop superhydrophobic coatings with excellent mechanical and chemical stability. In this work, silane coupling agent KH560 was used to modify titanium dioxide nanoparticles (TiO2) and blend them with epoxy resin E51 (EP). The mixed composite material was sprayed on the substrate for curing treatment. Form TiO2/EP superhydrophobic coatings with excellent mechanical and chemical stability. By adjusting the mass ratio of TiO2 to EP, it is found that the 1:3 TiO2/EP coating has excellent mechanical and chemical stability while having a contact Angle of 159.5° ± 1.5°. The layered bone structure brought by the modification of TiO2 by KH560 gives the coating excellent corrosion resistance. A series of tests have proved that the coating has a wider application prospect in super hydrophobic properties and harsh outdoor conditions.

Utilization of spent coffee grounds as charring agent to prepare flame retardant poly(lactic acid) composites with improved toughness

The objective was to utilize spent coffee grounds (SCG) as charring agent to combine with ammonium polyphosphate (APP) to prepare flame retardant poly(lactic acid) (PLA) composites with improved toughness. PLA/APP-SCG and PLA/APP-SCG/KH560 composites were prepared, and silane coupling agent KH560 was applied to improve particle-matrix interfacial compatibility. The particle-matrix interface, char formation, flame retardancy, mechanical properties and fracture morphology of PLA composites were studied. Results showed that PLA/APP-SCG5% and PLA/APP-SCG20% passed UL-94 V-0 rating, and increase in charred residues was favorable for improving flame retardancy. Improved toughness was also obtained compared to PLA, attributed to debonding of APP from matrix under external force as well as plasticization effect of coffee oil contained in SCG. PLA/APP-SCG5%/KH560 and PLA/APP-SCG20%/KH560 showed smaller elongation at break and impact strength compared to PLA/APP-SCG5% and PLA/APP-SCG20%, respectively. The improved interfacial compatibility was unfavorable for debonding of APP from matrix, and both APP and SCG played the role of enhancing strength, thus decreasing toughness. PLA/APP-SCG/KH560 counterparts were actually set as parallel samples to prove that PLA/APP-SCG composites showed improved toughness with weak interfacial compatibility. This study has provided a practical approach to utilize bio-derived wastes as charring agent to prepare flame retardant PLA composites with enhanced toughness.

Aggregation and Interfacial Adhesion of Nano-Sb2O3 Particles in Poly(Butylene Terephthalate) Composites: Effect of Surface Structure of the Nanoparticles

To study the effect of different surface structures on the aggregation level and interfacial adhesion, nano-Sb2O3 particles were treated with cetyltrimethylammonium bromide (CTAB), silane coupling agent KH550 and their compounds (CTAB + KH550). The surface properties and morphologies of the nano-Sb2O3 particles were characterized by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The aggregation level and interfacial adhesion of nano-Sb2O3 particles within PBT matrix were characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), and quantitatively evaluated by some semi-empirical parameters including aggregates size (Dagg ), real filling degree (Vre ), interfacial adhesion ( B ) and aggregated interfacial adhesion (Bagg ) from the tensile strength and the Young’s modulus measurements. The results showed that the highest interfacial adhesion and lowest aggregation level were obtained for the CTAB + KH550 modified nano-Sb2O3/PBT composites followed by the KH550 modified, CTAB modified and bare nano-Sb2O3/PBT composites, respectively.

Effect of Interfacial Modification on the Low-Temperature Fatigue Properties of Polymer/MXene Flexible Pressure Sensors.

Maintaining an excellent force-electric response under cyclic bending at low temperatures is still challenging for resistive-type electrically conductive polymer composite-based pressure sensors. In this study, the effect of low temperature on the fatigue failure of flexible MXene/polymer pressure sensors was systematically investigated through the silane functionalization of MXene nanosheets embedded with different polymer matrixes. The results show that the MXene/polymer interfaces are the primary factors affecting the temperature-dependent bending fatigue of the Cu/MXene/polymer/Cu sensor. Using finite element analysis and theoretical calculations, we reveal that the MXene/polymer interfaces are affected by free volume changes and the molecular chain motion under different temperatures. At room temperature, the well-distributed free volume in the polydimethylsiloxane (PDMS) matrix permits local segmental mobility that promotes the affinity between the polymer and MXene. As the temperature decreases, the free volume in the matrix shrinks with less space left for molecular chains to slide relatively, weakening the polymer/MXene interfacial bonding strength. However, for PDMS/MXene sensors with the interface modified using the silane coupling agent KH550, the nanoconstrained structure formed by strong hydrogen bonds and covalent bonds at the PDMS/MXene interface can hinder the mobility of polymer chains, which greatly helps to dissipate the inter/intrachain friction. It thus alleviates the debonding energy dissipation during cyclic bending at subzero temperatures.

Experimental study on modified lotus stem biochar-based catalysts for heavy oil aquathermolysis

To obtain high-activity catalysts for aquathermolysis at low temperatures, a composite modification method of KOH and silane coupling agent KH570 was used to successfully prepare modified lotus stem biochar (MLSB), and six catalysts with different ZrO2 and MoO3 contents (5–30 %) were synthesized by impregnation method. MLSB and catalysts were analyzed by SEM, N2 adsorption and desorption isotherms, surface pore size, and FT-IR. The results revealed that the pores of raw lotus stem biochar were increased and enlarged, and some -OH on the surface was replaced by hydrophobic groups to form hydrophobic supports. Catalysts had hydrophobic and strong acidic sites. The catalytic activities were evaluated by aquathermolysis experiments. Catalysts exhibited satisfying abilities to catalyze aquathermolysis at low temperatures (130–200 °C). Specifically, 25 % ZrO2−MoO3/MLSB catalyst displayed the optimal heavy oil viscosity reduction rate (86.1 %) at 200 °C, which was attributed to hydrophobicity, more active components and strong acid sites. The highest viscosity reduction rate of heavy oil was obtained with 25 % ZrO2−MoO3/MLSB at 200 °C and a catalyst content of 3 wt%. Continuing to increase the catalyst content decreased the viscosity reduction rate, likely due to catalyst agglomeration hindering the contact between the active component and heavy oil. Moreover, the viscosity reduction effect of the catalyst increased with higher reaction temperatures. Additionally, a reaction network of aquathermolysis catalyzed by ZrO2−MoO3/MLSB was proposed. These findings contribute to the development of efficient catalytic systems for aquathermolysis and provide insights into the application of biochar-based catalysts in heavy oil viscosity reduction.

Surface modification strategies for an improved interfacial compatibility between LLZO and a polymer substrate for applications in high-performance solid-state Li-metal batteries

The interfacial compatibility between inorganic powder and polymeric matrix is one of the most important key factors for the applications of polymer ceramic composite electrolytes (PCCEs). In the present study, a surface modification strategy has been proposed by using three different terminating groups of silane coupling agents in the modification of the interfacial compatibility between LLZO and PEO in PEO/LLZO composite electrolyte. Experiments and density functional theory (DFT) calculations have been performed in studying the effect of different silane coupling agents on interfacial properties. Especially, the interface compatibility is found to be improved when using amino-terminated silane coupling agent KH550, which is due to hydrogen bond interactions between amino groups and PEO. In addition, the mechanical strength and conductivity are significantly increased by increasing the interaction energy and by decreasing the crystallinity, and the values of 1.39 MPa and 0.22 mS cm−1 at 30 °C are then successfully achieved. As a result, the solid-state LiFePO4|PCCE|Li battery demonstrates a high discharge specific capacity of 157 mAh g−1 at 60 °C and 1C. And it has a cycle capacity decay rate of only 0.034 % for 380 cycles. These results pave the way for future developments of high-performance PCCEs.

The Photothermal Conversion and UV Resistance of Silk Fabrics Being Achieved through Surface Modification with C@SiO2 Nanoparticles.

With the improvement in people's living standards, the development and application of smart textiles are receiving increasing attention. In this study, a carbon nanosurface was successfully coated with a SiO2 layer to form C@SiO2 nanomaterials, which improved the dispersion of carbon nanomaterials in an aqueous solution and enhanced the absorption of light by the carbon nanoparticles. C@SiO2 nanoparticles were coupled on the surface of silk fabric with the silane coupling agent KH570 to form C@SiO2 nanosilk fabric. The silk fabric that was subjected to such surface modification was endowed with a special photothermal function. The results obtained with scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and infrared spectroscopy (FTIR) showed that C@SiO2 nanoparticles were successfully modified on the surface of the silk fabric. In addition, under the irradiation of near-infrared light with a power of 20 W and a wavelength of 808 nm, the C@SiO2 nanosilk fabric experienced rapid warming from 23 °C to 60 °C within 30 s. After subjecting the functional fabric to hundreds of photothermal experiments and multiple washes, the photothermal efficiency remained largely unchanged and proved to be durable and stable. In addition, the thermogravimetric (TG) analysis results showed that the C@SiO2 nanoparticles contributed to the thermal stability of the silk fabric. The UV transmittance results indicated that C@SiO2 nanofabric is UV-resistant. The silk modification method developed in this study is low-cost, efficient, and environmentally friendly. It has some prospects for future applications in the textile industry.

Antiferroelectric AgNbO3 @KH550 Doped PVDF/PMMA Composites with High Energy Storage Performance.

The residual polarization of antiferroelectric ceramics is very small, yet they possess high energy storage density and efficiency. Incorporating antiferroelectric ceramic particles into a polymer matrix is beneficial for improving the energy storage performance of composites. However, excessive amounts of ceramic particles can lead to aggregation within the polymer, resulting in defects and a significant reduction in composite film performance. In this study, the antiferroelectric AgNbO3 is selected as the filler and modified with silane coupling agent KH550. poly(vinylidene fluoride) (PVDF) and polymethyl methacrylate (PMMA) are blended as the matrix, and the energy storage performance of the composite is improved by adjusting the additional amount of PVDF. The structure, dielectric properties, and energy storage properties of the composites are systematically studied. The results show that hydrogen bonds are formed between PVDF and PMMA, and PVDF and PMMA are tightly bonded under the action of hydrogen bonds. The compatibility of PVDF with PMMA is optimal when the mass fraction of PVDF is 30 wt%. Moreover, with the synergistic effect of the antiferroelectric filler AgNbO3 , the breakdown strength of AgNbO3 /PVDF/PMMA composites reaches 430kV mm-1 , and the energy storage density reaches 14.35 J cm-3 .

Excellent dielectric and actuated strain properties in CCTOx@BT(1−x)@KH560/NR system via a tunable BaTiO3 interfacial buffer layer

AbstractDielectric elastomers (DEs) require high drive voltages to obtain large actuated strain, which limits their application in the biological field. In this work, we enhanced the dielectric properties of natural rubber (NR) composites by using core–shell structured (CaCu3Ti4O12)x@(BaTiO3)(1−x) (CCTOx@BT(1−x)) high‐dielectric particles with an buffer layer, and adjusted the thickness of the BT buffer layer by adjusting the addition of titanate during the preparation process, and then observed the relationship between the dielectric properties of NR composites and the thickness of the BT buffer layer. In addition, we modified the CCTO0.75@BT0.25 fillers surface with silane coupling agent KH560 to enhance the interfacial interaction between the inorganic fillers and polymeric matrix to obtain better dispersion and greater dielectric properties. As a result of the optimization of the CCTO0.75@BT0.25@KH560 structure, the actuated strain performance is greatly improved. The actuated strain of 5 per hundred rubber (phr) CCTO0.75@BT0.25@KH560/NR is 16.3% at 74.03 kV/mm, which is 6.52 times higher than the actuated strain obtained by NR (2.5%) at 50.28 kV/mm. This work presents a method to optimize the structure of core–shell fillers by modulating the buffer layer, and provides a new idea for further preparation of dielectric elastomer materials with large actuated strain at low voltage.