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The rapid development of lithium battery technology is leading to the increasing miniaturization of electronic devices, thereby elevating the demand for dielectric materials with exceptionally high thermal conductivity and dielectric properties. In this study, the composites were fabricated by integrating multilayer core-shell hybrid structure particles into silicone rubber (SR). These particles were created by attaching the conductive polymer polypyrrole (PPy) and the silane coupling agent (KH570) onto the surface of highly thermally conductive ceramic particles aluminum nitride (AIN). The combination of PPy and KH570 serves to enhance the interfacial compatibility between AIN and SR, thereby concurrently enhancing the thermal conductivity and dielectric properties of the composites. The experimental results demonstrated that the thermal conductivity of the 50 phr AlN-PPy-KH570/SR composite was 0.37 W/(m * K), 1.65 times higher than that of pure SR (0.23 W/(m * K)). Additionally, the dielectric constant of the composite increased to 4.59, 1.32 times that of pure SR (3.48). Moreover, the thermal decomposition temperature of the composite was elevated to 475[degrees]C. The synthesized SR composites hold promise for widespread use in miniaturized electronic devices operating in high-frequency and high-temperature environments. KEYWORDS aluminum nitride, dielectric properties, silicone rubber, thermal conductivity Highlights 1. Organic-inorganic core-shell AlN-PPy-KH570 particles structure were prepared. 2. The synergistic effect of PPy and KH 570 improve the thermal conductivity., 1 | INTRODUCTION With the rapid development of lithium battery technology, electrical devices are gradually shifting towards miniaturization [1,2]. This trend demands improved dielectric properties and thermal conductivity in dielectric [...]

Silica serves as the primary filler in the fabrication of eco-friendly tires, and achieving an optimal dispersion of polar silica within the natural rubber matrix is crucial for crafting high-performance rubber composites. In this study, biodegradable surfactants polyethylene glycol (PEG) with molecular weights of 200, 400, and 800 were employed to modiiy silica. The modified silica was characterized by Fourier-transform infrared spectroscopy; PEG-modified silica with different molecular weights was compounded with Si69, a conventional silane coupling agent, in the formulation. This aimed to reduce Si69 dosage and mitigate the emission of volatile organic gases, such as ethanol, generated during the silanization reaction between Si69 and silica. Experimental findings revealed that compared with natural rubber composites containing six parts of Si69, the addition of PEG-modified silica enhanced filler dispersion in the composite while reducing Si69 dosage by three parts. This led to accelerated vulcanization rates, effectively decreased energy consumption during production, and significantly improved wet slip resistance, while maintaining optimal rolling resistance. Rubber composites prepared with PEG800-modified silica exhibited a 10% increase in elongation at break, a 12% increase in tensile product coefficient, and a 19% enhancement in wet slip resistance. Highlights * Silica is modified by polyethylene glycol with molecular weight of 200. 400, and 800. * The amount of silane coupling agent and VOC emissions are reduced. * The interfacial bonding between silica and rubber matrix is enhanced. * The tensile product coefficient and wet slip resistance are improved by 12% and 19%. KEYWORDS modification, natural rubber, polyethylene slycol, silica, wet slip resistance, 1 | INTRODUCTION Natural rubber (NR) stands out as a renewable, bio-based polymer composed of cis-l,4-polyisoprene, obtained from the latex of rubber trees through coagulation and drying processes. In addition [...]

Cellulose fibers were modified via aqueous silane-graphene oxide (GO) coordination by flash drying and extrusion dispersion process. The adsorption of GO reduced the polarity of the cellulose fiber surface and attenuated the agglomeration effect between the cellulose fibers, thus facilitating the dispersion of fibers in the rubber matrix. Adding aqueous 3-aminopropylsilane oligomer (8150) incorporated active sites on the surface of cellulose fibers, thereby improving the interfacial binding properties of cellulose nano fibers (CNFs) and natural rubber (NR). After blending the modified CNFs with NR latex, high-temperature flocculation was performed using an atomised flash device. Finally, CNF/NR was pre-dispersed through a twin-screw extruder, after which a CNF/NR masterbatch with excellent performance was prepared. Experimental results revealed that composites prepared using GO-8150 via the flash drying-twin-screw dispersion process exhibited excellent dispersion characteristics, processing properties, mechanical properties, rolling resistance, wear resistance, and heat generation properties. Compared with traditional dry mixing, the composites prepared by flash drying-twin-screw dispersion process showed a 16.95% increase in tensile strength, 16.07% increase in 300% constant elongation, 19.01% reduction in abrasion consumption, 42.26% reduction in rolling resistance, and a reduction in the Payne effect. This study offers an efficient and environmentally friendly method for the high-value utilization of natural fibers and the preparation of NR composites with excellent properties, while providing a green and nonpolluting modification process with no acidic liquid discharge. Highlights * GO-8150 reduces the polarity of the fibers and promotes dispersion. * The flash extrusion dispersion process achieves green flocculation. * 42% lower rolling resistance for rubber composites. KEYWORDS aqueous silane, cellulose fiber, graphene oxide, natural rubber, rolling resistance, 1 1 INTRODUCTION Carbon black, silica, wollastonite, and calcium carbonate are commonly used as fillers in the rubber industry. In recent years, efforts have been made to limit the use [...]

Purpose: To measure zirconia-to-zirconia microtensile bond strength (µTBS) using composite cements with and without primer. Materials and Methods: Two Initial Zirconia UHT (GC) sticks (1.8x1.8x5.0 mm) were bonded using four cements with and without their respective manufacturer's primer/adhesive (G-CEM ONE [GOne] and G-Multi Primer, GC; Panavia V5 [Pv5]), and Panavia SA Cement Universal [PSAu], and Clearfil Ceramic Plus, Kuraray Noritake; RelyX Universal (RXu) and Scotchbond Universal Plus [SBUp], 3M Oral Care). Specimens were trimmed to an hour-glass shaped specimen whose isthmus is circular in cross-section. After 1-week water storage, the specimens were either tested immediately (1-week µTBS) or first subjected to 50,000 thermocycles (50kTC-aged µTBS). The fracture mode was categorized as either adhesive interfacial failure, cohesive failure in composite cement, or mixed failure, followed by SEM fracture analysis of selected specimens. Data were analyzed using linear mixed-effects statistics (α = 0.05; variables: composite cement, primer/adhesive application, aging). Results: The statistical analysis revealed no significant differences with aging (p = 0.3662). No significant difference in µTBS with/without primer and aging was recorded for GOne and PSAu. A significantly higher µTBS was recorded for Pv5 and RXu when applied with their respective primer/adhesive. Comparing the four composite cements when they were applied in the manner that resulted in their best performance, a significant difference in 50kTC-aged µTBS was found for PSAu compared to Pv5 and RXu. A significant decrease in µTBS upon 50kTC aging was only recorded for RXu in combination with SBUp. Conclusion: Adequate bonding to zirconia requires the functional monomer 10-MDP either contained in the composite cement, in which case a separate 10-MDP primer is no longer needed, or in the separately applied primer/adhesive. [ABSTRACT FROM AUTHOR]

We report a Pt-catalyzed double deoxygenative transformation of N-acyloxyamines, employing PtCl 2 catalyst without external ligand under mild conditions. This method facilitates efficient C–N bond formation and can be used to synthesize a broad spectrum of alkylated secondary and tertiary amines with excellent yields. The adaptability and effectiveness of this approach highlight the potential of platinum catalysis to extend beyond traditional synthetic boundaries. [ABSTRACT FROM AUTHOR]

AbstractThe use of industrial by products such as steel slag as aggregate substitutes is crucial for sustainable pavement rehabilitation. This study investigated the combined modification of steel slag using silica powder and silane coupling agents to enhance its surface properties. The innovative combined modification process overcomes the limitations of traditional silica powder solutions by forming a robust bond between the modified steel slag and asphalt. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed that silica powder-modified steel slag formed a C-S-H gel network, while silane-modified steel slag exhibited a layered structure with polysiloxanes. Enhanced adhesion and freeze-thaw resistance were observed in the modified steel slag compared to its unmodified variant, while refined soaking tests confirmed the improved bond strength between the modified steel slag and asphalt. Performance evaluations indicated that when that RAP content is 30%, the optimal addition of modified steel slag is 10%, which improved pavement performance significantly. The combined modification method enhances not only recycled asphalt mixtures’ mechanical properties and durability, but also promotes sustainability and cost-efficiency in pavement construction. [ABSTRACT FROM AUTHOR]

We have developed an efficient method for the synthesis of 2,3-dihydro-1 H -1-benzosiloles in 19% to 90% isolated yield from 1-hydrosilyl-2-ethynylbenzenes by using two equivalents of diisobutylaluminum hydride. The reaction mechanism involves regioselective double hydroalumination of the alkyne moiety followed by cyclization to a 2-alanyldihydrobenzosilole. A silacyclopentane (silolane) was also synthesized in 97% isolated yield from the corresponding 4-silylbut-1-yne under the same reaction conditions. Although the substrate-scope study was conducted on a 0.5-mmol scale, a gram-scale reaction of (2-ethynylphenyl)(diphenyl)silane under the optimized reaction conditions successfully afforded the desired product in 94% isolated yield without loss of reactivity. [ABSTRACT FROM AUTHOR]

The influence of organosilicon compounds on butyl sealant blends' mechanical and processing properties was investigated, particularly under increased humidity conditions. The addition of (3-mercaptopropyl)trimethoxysilane (MPTES), (3-aminopropyl)triethoxysilane (APTES), vinyltrimethoxysilane (VTMOS), and (3-glycidoxypropyl)trimethoxysilane (GLYMO) to elastomeric blends containing butyl rubber (IIR) and polyisobutylene (PIB) was studied. Key rheological parameters, including Mooney viscosity and melt volume rate (MVR), along with mechanical attributes such as peel resistance and cone penetration, were evaluated. Results indicated that functionalized silanes enhance sealant cohesion when their functional groups interact with the matrix and form cross-links under humid conditions. The presence of unreacted silanes acts as a plasticizer, increasing MVR and reducing viscosity. A notable MVR increase, up to 109 mL/10 min, was observed for the APTES-10 system. The most significant mechanical property enhancements were observed in blends containing MPTES and APTES, resulting in increased cohesion and peel resistance. The findings of this research are of considerable practical relevance, demonstrating that the modification of rubber sealants with monofunctional silanes improves their cohesion, delamination resistance, and processability, thereby making these materials suitable for the production of more durable sealants. [ABSTRACT FROM AUTHOR]

Sodium tungstate (Na2WO4) was filled into the micropores and onto the surface of a magnesium alloy microarc oxidation (MAO) coating by means of vacuum impregnation. Subsequently, the coating was sealed through silane treatment to synergistically boost its corrosion resistance. The phase composition of the coating was inspected using XRD. FTIR was utilized to analyze the functional groups in the coating. XPS was employed to study the chemical composition and valence state of the coating. The surface and cross-sectional morphology of the coating, along with its elemental composition and distribution, were investigated by SEM and EDS. Meanwhile, the thickness of the coating was analyzed using Image J software. Electrochemical impedance spectroscopy (EIS) was employed to determine the corrosion resistance of the coating. The results show that compared with an MAO coating, M-0.125W composite coating (only filled with sodium tungstate on the surface of the MAO coating), and M-SG composite coating (only receiving silanization treatment applied to the surface of the MAO coating), the corrosion resistance of the M-nW-SG composite coating (loaded with sodium tungstate on the surface of the MAO coating and then treated with silane) is significantly improved. This is mainly attributed to the fact that sodium tungstate can be combined with Mg2+ to form insoluble magnesium tungstate protective film, which blocks corrosion media. At the same time, silanization treatment further seals the MAO coating and increases the compactness of the coating. In addition, with the increase in the impregnation concentration of sodium tungstate, the content of sodium tungstate in the M-nW-SG composite coating improves, and the sealing effect of silanization treatment is better. When the impregnation concentration of sodium tungstate is 0.1 mol/L or above, the MAO coating with sodium tungstate can be completely sealed. When the impregnation concentration of sodium tungstate is 0.125 mol/L, M-0.125W-SG composite coating has the best corrosion resistance, and its impedance modulus value can be maintained at 8.06 × 106 Ω·cm2 after soaking in 3.5 wt.% NaCl solution for 144 h, which is about three orders of magnitude higher than those of MAO coating and M-0.125W and M-SG composite coatings. [ABSTRACT FROM AUTHOR]

This study assesses the effectiveness of a specially developed surface‐modified carbon black, both on its own and in combination with nano‐silica, as a hybrid filler for ethylene–propylene–diene monomer (EPDM) rubber compounds. The modification process, which included treatment with a silane coupling agent, resulted in enhanced curing characteristics. The ∆Torque values for compounds incorporating the modified carbon black exceeded those of other formulations by 25.85%. Scanning electron microscopy (SEM) analysis demonstrated improved filler dispersion and better compatibility between rubber and filler due to the surface modification. The silane‐modified carbon black showed considerable enhancements in mechanical properties, particularly in tear resistance, with increases in tensile and tear strength of 22.46% and 34.86%, respectively, following surface treatment. Dynamic mechanical analysis (DMA) indicated the influence of both surface modification and filler type, revealing that the combination of modified carbon black and nano‐silica achieved a reduction in rolling resistance of 20.41% and enhanced ice and wet grip performance by 7.95%. Additionally, modified carbon black displayed varying effects on the glass transition temperature. Thermal gravimetric analysis (TGA) confirmed that the thermal stability of the compounds was consistent, while solvent resistance improved with surface modification, as shown by swelling ratios. Thermodynamic analysis indicated that the surface modification of carbon black positively influences the elasticity and chain mobility of the rubber compounds studied. In conclusion, the careful selection and optimization of filler materials and their modifications are essential for customizing the properties of rubber compounds to satisfy specific performance criteria and applications. Highlights: Promising EPDM compounds were prepared with Silane‐Modified CB and Nano‐Silica.Silane‐modified CB effectively improved the curing properties of the EPDM compound.The ΔTorque and cross‐link density of modified CB/EPDM show the highest value.Modified CB/Nano‐Silica/EPDM exhibited significant improvement in tear strength.Modified CB/Nano‐silica/EPDM have lower rolling resistance and higher wet grip. [ABSTRACT FROM AUTHOR]

Bis(catecholato)silanes were showcased as strong Lewis acids, while their inherent redox activity remained unexplored in this context. In the present work, we study the oxidation of monomeric bis(3,6-di-tert-butyl-catecholato)silane (1), leading to the Lewis superacidic radicalic silylium ionradical 1•+ (FIA 784 kJ mol−1). Oxidation of 1 with [N(p-C6H4Br)3][B(C6F5)4] yielded [1][B(C6F5)4], displaying strong catalytic activity in the Friedel–Crafts-dimerization, hydrodeoxygenation and carbonyl-olefin-metathesis. It demonstrates how Lewis acidity can be amplified through oxidation without needing an add-on redox-active substituent. Instead, it synergizes the constraining effect of catecholates with their inherent redox non-innocence to unlock enhanced catalytic performance. [ABSTRACT FROM AUTHOR]

Objective To evaluate the effect of silane-free universal adhesives systems on the repair shear bond strength (SBS) of sonic-activated bulk-fill [SonicFill (SF) Kerr, USA] composite applying additional silane in the repair of bulk-fill composite. Methods Sonic-activated bulk-fill composite samples (n=40) were prepared using a teflon mold (6 mm x 4 mm) and polymerized. Then all samples were kept in an incubator to simulate the aging process at 37 °C for one month. Aged composite samples were embedded in acrylic resin. For the repair, the specimen surfaces were roughened with a diamond bur. They were divided into 2 groups (n=20) according to the adhesive system used and then into two subgroups (n=10) as additional silane was applied or unapplied. Adhesive systems Ambar Universal Bond (AUB), (FGM, Brazil), G-Premio Bond (GPB) (GC, USA) and silane (G-Multi primer GC, Tokyo, Japan) were applied according to the manufacturer's instructions. Samples were subjected to a shear bond test in a universal testing device. For statistical analysis, one-way ANOVA test was performed (p<0.05). Results The highest SBS value was obtained in the silane-treated AUB group (21.88±6.4), while the lowest SBS value was obtained in the silane-treated GPB group (16.07±6.2). No statistically significant difference was observed between all groups (p<0.05). Conclusion Additional silane application does not affect the SBS of universal adhesives on an SF composite material. Keywords:Bulk-fill composite repair, sonic-activated bulk-fill composite, surface treatments, silane agent, universal adhesive: [ABSTRACT FROM AUTHOR]

Cancer, a leading cause of death globally, necessitates clinical research to develop effective solutions to reduce mortality rates. Currently, scientists are focusing on two prominent topics in cancer treatment: the presence of Sn2+ in cells and the inhibition of the phosphoinositide 3‐kinase enzyme (PI3Kα). In this study, Schiff base‐coupled silane 7a {C26H35N5O6Si (M + H+ = 540.53)} has been synthesized that could detect Sn2+, which in trace amounts can help prevent cancer, and it also inhibits PI3Kα enzyme, thereby preventing the rapid proliferation of cancer cells. The detection limit and binding constant calculated via Fluorescence studies were found to be 3.46 × 10−8 M and 9.4 × 104 M−1, respectively. The value of inhibition constant of silane for PI3Kα enzyme was also found to be 2.52 nM via molecular docking. [ABSTRACT FROM AUTHOR]

Although there are many reports on deprotonation of carbon analogues, there are only a few reports on deprotonation from silanes. This is because the lone pair of a base mainly attacks hydrogen of a C–H bond and deprotonates, whereas in the case of silanes, the base is added to the silicon atom of a Si–H bond. Previous reports have shown that deprotonation from silanes requires the assistance of negative hyperconjugation by silyl substituents or intramolecular chelating groups (pincer ligands). We proposed that lithium and hydrogen exchange approach could be applied to the deprotonation of monosilanes using bulky silyllithium instead of some bulky strong bases, such as t-butyllithium and LDA. Here, we report the first successful approach to the deprotonation of monosilanes without intramolecular chelation. [ABSTRACT FROM AUTHOR]

Highlights Nowadays, natural fibers are in greater demand as compared to synthetic fibers because of their various benefits, such as affordability, lightweight, biodegradability, and environmental friendliness. Ramie is one such natural fiber that is gaining importance owing to its outstanding mechanical properties. This article examines the literature on ramie fibers as a reinforcing material, with the main emphasis on the recent decade (2013–2023). Various studies on surface treatments to improve the bonding and properties of ramie fiber‐reinforced composites (RFRCs) are discussed. The tribological and mechanical properties of several RFRCs are explored. The applications of ramie‐based composites in several industrial areas are also highlighted. The findings of this review indicate that a combination of alkali and silane surface treatment greatly improves the mechanical and thermal behavior of RFRCs, whereas treating ramie fibers with ammonium polyphosphate enhances their flame retardant properties. Furthermore, the lack of literature on the characterization of RFRCs with different filler materials, such as rice husk, eggshell powder, waste tire particles, and fishbone powder needs to be studied. The insufficient studies on the tribological behavior of RFRCs, particularly in thermoplastic polymers, highlight research gaps that demand attention from researchers to understand their potential for wear‐resistant applications. Surface treatments enhance ramie fiber‐polymer bonding. Alkali + silane treatment boosts composite rigidity. Ammonium polyphosphate improves flame retardancy. Hybrid ramie/epoxy with synthetic fibers shows strong mechanical properties. Research needed on RFRCs with LDPE, PC, and various filler materials. [ABSTRACT FROM AUTHOR]

Purpose: This study assesses the impact of Cold Atmospheric Pressure Plasma (CAP) pretreatment on the bond strength of two-piece hybrid ceramic abutment crowns in implant dentistry. The objective is to ascertain whether CAP can be employed as an alternative or complementary technique to conventional methods. Methods: 80 titanium bases and 80 VITA ENAMIC® polymer-infiltrated ceramic network (PICN) crowns were divided into 8 groups (n = 10) based on different surface pretreatments of the crowns before cementation: no treatment (A), hydrofluoric acid (HF) (B), HF and silane (C), silane (D), CAP (AP), HF and CAP (BP), HF, CAP, and silane (CP), and CAP and silane (DP). Bond strength (BS) was measured after thermocycling (5000 cycles at 5 °C/55 °C), and statistical analysis was performed using three-way ANOVA. Results: The highest bond strength (BS) was recorded in the conventionally pretreated group C. Both HF and silane alone had significant effects (p < 0.0001), but CAP alone did not (p = 0.9377). Significant interactions were found between silane and CAP (p = 0.0222), and HF and CAP (p = 0.0046). The combined effects exceeded individual effects. Although group C showed the highest BS, no significant interaction was found between HF and silane (p = 0.6270). Three-factor interactions were significant (p < 0.0001). Conclusion: In the setting used, CAP could not replace conventional pretreatment. The highest BS of a group without HF was achieved by combining silane with CAP. However, BS of this pretreatment was approximately 24% lower than that of the conventional pretreatment. [ABSTRACT FROM AUTHOR]

The valorization of plant wastes for developing environmentally friendly composites has garnered increasing attention over the past two decades. The management of a significant quantity of Nile rose plant waste presents a mounting challenge, particularly in light of escalating water demand. This study delves into the impact of Nile rose fiber (RF) loading and utilizing Vinyltrimethoxysilane (VTMS) as a coupling agent on the characteristics of a composite comprising RF and natural rubber (NR). The verification of the fiber structure treated with silane (TF) was accomplished via Fourier transform infrared (FTIR) spectroscopy. The crosslinking between the NR matrix and the fibers is promoted by the formation of siloxane (SiOSi) linkages in 1050–1100 cm−1. An extensive evaluation of the impact of RF on the characteristics of NR composite was conducted, encompassing morphological properties, mechanical characteristics, and water absorption resistance. The results of the morphological analysis revealed that the modification of RF with silane enhanced the interfacial adhesion between RF and NR. Furthermore, the tensile strength (TS) of NR increases to values of 7.31 and 8.5 MPa by an improvement of 61% and 88% when 10 and 15 phr of TF are added, respectively. Moreover, rubber composites with silane exhibited superior water resistance to those without it across various filler loadings. Specifically, the composite with 20 phr TF absorbed 7% water, whereas the counterpart with untreated fiber (RF) absorbed 12.5% water. The analysis of swelling validated that the interaction between the RF and NR is significantly impacted by the modification of fiber and its incorporation into the composite, as evidenced by the decreased swelling index values from 367% to 298% observing in composites incorporating TF as opposed to those containing RF. Highlights: Silane treatment improves the interaction between RF and NR.The TF and NR matrix interacted more and developed an interfacial bonding.The rate of vulcanization is accelerated in the presence of treated RF.TF/NR composites have fewer voids and microcracks, inhibiting water diffusion.15% TF content optimal for good physical and mechanical properties. [ABSTRACT FROM AUTHOR]

The present study investigated for the first time the characteristic length scale and chemical dynamics of steady and quasi-steady detonation waves propagating in silane-nitrous oxide-nitrogen mixtures, which are widely used in the semi-conductor industry and can be a promising additive for propulsion application. The conditions investigated cover the following ranges: equivalence ratio $\phi $ ϕ = 0.5–5; initial pressure ${P_1}$ P 1 = 10–1000 kPa; nitrogen mole fraction ${X_{{{\rm{N}}_2}}}$ X N 2 = 0–0.8; initial temperature ${T_1}$ T 1 = 300 K. The energy released by the formation of SiO(s) and SiO2(s) was taken into account whereas the phase change from gas to liquid/solid was neglected. It was found that detonation in these silane-based mixtures is characterized by unusually large Mach numbers which result in up to 128.5 times pressure jump across the leading shock, and few micrometer-long induction zone length. For steady planar waves, the shortest induction distances were identified in the range $\phi $ ϕ = 2–4, while for curved detonations, the most resilient wave to curvature-induced losses was identified at $\phi $ ϕ around 1.5 for undiluted mixtures. Such phenomena are the results of the enhanced formation of SiO(s) under fuel-rich conditions, which also contributes to stabilizing the detonation wave, though the mixture should still be classified as unstable, according to traditional stability parameters. Detailed thermo-chemical analyses were performed to investigate the chemical dynamics. The study of the heat release per reaction shows the dominant contributions of R65: H+N2O=N2+OH, R207: SiH4(+M)=H2+SiH2(+M), R377: N2O+SiH2=H2SiO+N2, R379: N2O+Si=N2+SiO, and R400: 2SiO = 2SiO(s). The dominant reactions for heat release are not modified by the curvature-induced loss according to sensitivity analyses. [ABSTRACT FROM AUTHOR]

The paper presents the results of numerical calculations to study the dynamics of the conversion of small impurities of silane SiH4 in buffer helium in a glow discharge at low pressures. It has been shown that the main products of silane conversion are atomic hydrogen, the SiH radical, and atomic silicon Si. An increase in the concentration of silane impurity leads to an increase in the concentrations of Si2H5 and Si3H8. The effect of plasma stratification in a short glow discharge (in negative glow) has been demonstrated and qualitatively described, when ion-ion plasma dominates in its central region, and electron-ion plasma dominates at the periphery near the cathode and anode layers. [ABSTRACT FROM AUTHOR]

Microspheres composed of Y-containing materials are effective agents for cancer radioembolization therapy using β-rays. The distribution and dynamics of these microspheres in tissues can be easily determined by providing the microspheres with an imaging function. In addition, the use of quantum dots will enable the detection of microspheres at the individual particle level with high sensitivity. In this study, core – shell quantum dots were bound to chemically modified yttria microspheres under various conditions, and the effect of reaction conditions on the photoluminescence properties of the microspheres was investigated. The quantum dots were immobilized on the surfaces of the microspheres through dehydration – condensation reactions between the carboxy groups of quantum dots and the amino groups of silane-treated microspheres. As the reaction time increased, the photoluminescence peak blue shifted, and the photoluminescence intensity and lifetime decreased. Therefore, a moderate period of the immobilization process was optimal for imparting effective photoluminescence properties. This study is expected to facilitate particle-level tracking of microsphere dynamics in biological tissues for the development of minimally invasive cancer radiotherapy of deep-seated tumors. IMPACT STATEMENT: We have established a method to immobilize quantum dots on yttria microspheres for cancer radiotherapy and revealed that photoluminescence intensity can be optimized by controlling the immobilization treatment time. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the shear bond strength (SBS) when bonding a universal resin cement to a disilicate glass‐ceramic using different adhesive protocols. Sixty specimens were etched with 10% hydrofluoric acid (HF) for 20 s and assigned to one of four treatment protocols (n = 15): The Positive control protocol comprised use of a universal adhesive system + adhesive resin cement; the Test1 protocol comprised use of a new universal adhesive system + universal resin cement; the Test2 protocol comprised use of a silane coupling agent + universal resin cement; and the use of a universal resin cement without adhesive and silane served as the Negative control. One of the two resin cement cylinders built on each specimen in each group was used to test for 24‐h SBS, while the other was thermocycled and then tested for SBS. Data were submitted to two‐way ANOVA, Tukey's test, and Weibull analysis. The negative control (24 h) showed the lowest SBS mean value. The Test2 protocol resulted in the highest SBS mean value after thermocycling. Adhesive and mixed failures were prevalent in all groups. No statistical difference in m values was observed among the groups at 24 h. After thermocycling, the two Test protocols showed the highest m values. The m values were significantly lower after thermocycling than at 24 h for all groups. After thermal aging, The Test2 protocol resulted in a statistically significantly higher SBS mean value after thermal aging than seen for the other groups. [ABSTRACT FROM AUTHOR]

Objectives: To assess the influence of different primer compositions—silane (S), 10-methacryloyloxydecyl dihydrogen phosphate (MDP), and the combination of silane and MDP (S + MDP)—on the bonding performance of MDP-free and MDP-containing resin cements to highly translucent zirconia. Materials and methods: Tribochemical silica-coated zirconia plates were pretreated with one of three experimental primers, S, MDP, or S + MDP, with untreated specimens serving as controls. Subsequently, these plates were bonded to stainless-steel rods using either two MDP-free or two MDP-containing resin cements. Tensile bond strength was measured after 24 h (TC0) and following thermal cycling (4–60 °C for 10,000 cycles; TC10,000). Data were analyzed using a three-way analysis of variance (ANOVA), followed by one-way ANOVA and Tukey-Kramer post hoc tests (α = 0.05). X-ray photoelectron spectroscopy (XPS) assessed the elemental mass concentrations on the zirconia surfaces. Results: For MDP-free resin cements, MDP-treated specimens exhibited significantly greater bond strengths than controls, regardless of the aging conditions. However, a significant reduction in bond strength was observed between TC0 and TC10,000 in most of the MDP-free resin cement groups, except for one S + MDP group. Conversely, for MDP-containing resin cements, the S + MDP group exhibited no statistically significant differences between aging conditions. Notably, XPS analysis detected silicon, zirconium, and aluminum on the zirconia surfaces. Conclusions: No significant difference in tensile bond strength was observed between aging conditions for MDP-containing resin cements bonded to tribochemical silica-coated zirconia primed with S + MDP. Clinical relevance: The combination of MDP-containing primers and resin cements demonstrated superior bonding performance to tribochemical silica-coated zirconia. [ABSTRACT FROM AUTHOR]

Vinyltrimethoxysilane (VTMS) functionalized ethylenic polymers, in the form of reactor‐made ethylene‐silane copolymers as well as post‐reactor made silane‐grafted ethylene polymers, were evaluated for the purpose of moisture‐induced crosslinking through hydrolysis and condensation reactions. The copolymers were of 1.6 wt% or 4.2 wt% VTMS contents, and the silane‐grafted resins ranged in VTMS contents from 1.1 to 3.7 wt%. The silane‐grafted materials were very reactive under humid conditions at room temperature, resulting in very poor shelf stabilities manifested in sharp drops in their melt indices over time (changes that in the early stages were dominated mostly by resin molecular weight distribution and/or branching, and in the later stages much more by silane content). In sharp contrast, the ethylene‐silane copolymers exhibited outstanding shelf stabilities over time even at relatively high silane content, indicating desirably low reactivities in the absence of moisture‐cure catalyst. When formulated with catalyst, and exposed to humid conditions, the cure characteristics of the silane functionalized ethylene polymers varied significantly, with the fastest and greatest crosslinking observed using the ethylene‐silane copolymer of 4.2 wt% VTMS content and remarkably excellent shelf stability. Analyses of reaction rates revealed very interesting trends, depending on type of catalyst (tin or sulfonic acid) and resin. Highlights: Ethylene‐silane copolymers and silane‐grafted ethylene polymers were studied.Copolymers exhibited vastly superior shelf stabilities than grafted materials.Catalyst type and loading affected moisture‐induced crosslinkability.Increased silane content in copolymer led to faster and greater crosslinking.Best balance of crosslinkability and shelf stability obtained with copolymers. [ABSTRACT FROM AUTHOR]

Due to commonly observed adhesive fracture, the interphase regions between fibers and matrix have often been considered a critical design factor in polymer matrix composites. This study uses molecular dynamics simulation to explore the effects of two modifications at a glass fiber and epoxy interphase by adding a silane sizing and a cellulose nanocrystal particle. The interphase thickness increases by 1 nm and by 3.8 nm, respectively, when silane coating, a combination of silane and a 36-chain cellulose nanocrystal are added. Furthermore, the shear modulus and strength of the interphase increase by around 120% and 415% in the case of silane and by about 70% and 240% in the case of a cellulose nanocrystal. When both cellulose nanocrystal and silane are added at interphase, the shear modulus and strength increase by approximately 125% and 265%, respectively. The cellulose nanocrystal particle is physically absorbed on the glass fiber surface without silane, and it is physically confined in a region created by covalent bonds between silane and epoxy when silane is present. In both cases, a cellulose nanocrystal particle increases the nanoscale roughness at a glass fiber surface, leading to improved shear properties at the interphase. [ABSTRACT FROM AUTHOR]

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Objectives: This study was designed to assess the effectiveness of chitosan as a coupling agent for improving the tensile bond strength of fiber posts. Methods: A total of 91 single-rooted mandibular teeth were root canal-filled. Post spaces were created and categorized into seven groups: Group A (Control), Group B (Silane), Group C (Chitosan), Group D (37% Phosphoric acid + Silane), Group E (37% Phosphoric acid + Chitosan), Group F (10% Hydrogen Peroxide + Silane), and Group G (10% Hydrogen Peroxide + Chitosan). Posts were cemented and tensile bond strength was measured, while the morphological structure of the fiber posts was analyzed using Scanning Electron Microscopy. One-way (ANOVA) and Tukey's multiple comparison tests were performed at a level of significance of 5%. The percentages of fracture patterns among the groups were compared. Results: 10% Hydrogen peroxide + Chitosan exhibited the significantly highest tensile bond strength (p < 0.001). Adhesive failures were more frequent in Groups A, B, C, and D, whereas cohesive failures within the resin cement were predominant in Groups E, F, and G. Conclusions: The protocol of using 10% hydrogen peroxide followed by a chitosan coupling agent significantly improved tensile bond strengths for glass fiber posts, which highlights the potential of using chitosan as a natural biopolymer and an alternative to synthetic coupling agents to develop more effective bonding strategies for dental restorations. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated the effects of resin matrix composition and surface treatment on the bond strength of glass fiber-reinforced composite (FRC) posts to intraradicular dentin. Methods: Fifty-six extracted premolars were obtained. Post spaces were prepared for either epoxy resin-based posts (White Post DC) or Bis-GMA-based posts (Postec Plus) (n=28). The posts received different surface treatments (n=7): 70% ethanol (control), air abrasion and silanization, 35% H3PO4, and 24% H2O2. Posts were cemented and the samples were sectioned into cervical, middle, and apical thirds. The push-out bond strength of samples was compared between the groups using two-way ANOVA (a=0.05). Results: There was a significant difference in bond strength between the different treatment methods in all root sections (P < 0.05). The highest push-out bond strength in the cervical, middle, and apical sections was observed in subgroups treated with air abrasion and silanization, with a significant difference from other groups in most comparisons (P < 0.05). Epoxy resin and Bis-GMA posts had comparable bond strengths in the coronal and apical sections (P > 0.05). Additionally, their bond strengths were comparable in the middle section when the post surfaces were treated with air abrasion and silanization, or 35% H3PO4 (P > 0.05). Conclusions: Air abrasion and silanization could be suggested as the optimal surface treatment strategy to improve the bond strength of FRC posts to resin cement. Proper mechanical and chemical surface treatments might be more important than the resin matrix composition in determining the bond strength of FRC posts. [ABSTRACT FROM AUTHOR]

Abstract Background To assess the influence of various factors on the bond strength of glass-based ceramics and develop a model that can predict the bond strength values using machine learning (ML). Methods The bond strength values of lithium disilicate-reinforced glass–ceramics were collected from existing literature. Nineteen features were listed, and 9 ML algorithms, including logistic regression, k-nearest neighbors, support vector machine, decision tree, ensemble methods (extra trees, random forest, gradient boosting, and extreme gradient boosting), and multilayer perceptron, were employed. Importance analysis was performed to determine the significance of the 19 features. A new data set comprising the top five contributing features was used for bond strength class prediction. Grid search cross-validation (CV) and stratified tenfold CV were employed for hyperparameter tuning and model performance assessments. The evaluation metrics used were the area under the receiver operating characteristic curve (AUC) and accuracy. Nested CV was also employed to assess the model performance and avoid untruly optimistic results. Results A total of 193 bond strength values were collected. Hydrofluoric acid concentration and etching time, gamma-methacryloxypropyltrimethoxysilane or 10-methacryloxydecyldihydrogen phosphate in the primer, and Bis-GMA in the cement were the top five features contributing to the bond strength. Stratified CV produced AUC scores of 0.71–0.93 and accuracy scores of 0.64–0.83. Extreme gradient boosting achieved superior model performance and accuracy and demonstrated good performance in predicting the range of bond strength values. Conclusions ML shows promise as a data-driven tool for predicting the bond strength of glass-based ceramics to resin.

Objective: This study evaluated the effects of resin matrix composition and surface treatment on the bond strength of glass fiber-reinforced composite (FRC) posts to intraradicular dentin.Methods: Fifty-six extracted premolars were obtained. Post spaces were prepared for either epoxy resin-based posts (White Post DC) or Bis-GMA-based posts (Postec Plus) (n=28). The posts received different surface treatments (n=7): 70% ethanol (control), air abrasion and silanization, 35% H3PO4, and 24% H2O2. Posts were cemented and the samples were sectioned into cervical, middle, and apical thirds. The push-out bond strength of samples was compared between the groups using two-way ANOVA (α=0.05).Results: There was a significant difference in bond strength between the different treatment methods in all root sections (P < 0.05). The highest push-out bond strength in the cervical, middle, and apical sections was observed in subgroups treated with air abrasion and silanization, with a significant difference from other groups in most comparisons (P < 0.05). Epoxy resin and Bis-GMA posts had comparable bond strengths in the coronal and apical sections (P > 0.05). Additionally, their bond strengths were comparable in the middle section when the post surfaces were treated with air abrasion and silanization, or 35% H₃PO₄ (P > 0.05).Conclusions: Air abrasion and silanization could be suggested as the optimal surface treatment strategy to improve the bond strength of FRC posts to resin cement. Proper mechanical and chemical surface treatments might be more important than the resin matrix composition in determining the bond strength of FRC posts.