Epoxy-functionalized Silane Research Articles

Modification of NiCoP nanocages anodes using epoxy-functionalized silane to improve electrochemical performance in lithium-ion batteries

Modification of NiCoP nanocages anodes using epoxy-functionalized silane to improve electrochemical performance in lithium-ion batteries

Influence of epoxy functional silane on the crosslinking process of eucalyptus wood panels using formaldehyde-free acrylate adhesives

ABSTRACT The effect of different amounts of epoxy functional silane (EFS) as a crosslinking agent in the water-based acrylate adhesives was evaluated for the production of eucalyptus wood panels at different curing temperatures (120°C and 140°C). The thermal stability and dynamic analyses (loss and storage moduli) of the acrylate adhesives with EFS were evaluated. The addition of EFS in the acrylate adhesive increased the thermal degradation, storage, and loss moduli. The thermal degradation, bending test, specific mass, and morphology were evaluated in the wood panels. Significant increases in the storage modulus and bending strength of the wood panels with EFS and acrylate adhesive at 140°C were found. These results demonstrate a potential application of EFS in the production of wood panels aiming towards the manufacture of thicker composites.

Dual-Mode Sensing Platform for Cancer Antigen 15-3 Determination Based on a Silica Nanochannel Array Using Electrochemiluminescence and Electrochemistry

An electrochemiluminescence-electrochemistry (ECL-EC) dual-mode sensing platform based on a vertically-ordered mesoporous silica films (VMSF) modified electrode was designed here for the sensitive and selective determination of cancer antigen 15-3 (CA 15-3), a specific biomarker of breast cancer. VMSF was assembled through a rapid electrochemically assisted self-assembly (EASA) method and plays a crucial role in signal amplification via a strong electrostatic interaction with the positively charged bifunctional probe Ru(bpy)32+. To construct the biorecognition interface, epoxy functional silane was linked to the surface of VMSF for further covalent immobilization of the antibody. As a benefit from the specific combination of antigen and antibody, a non-conductive immunocomplex layer was formed in the presence of CA 15-3, leading to the hinderance of the mass and electron transfer of the probes. Based on this strategy, the dual-mode determination of CA 15-3 ranging from 0.1 mU/mL to 100 mU/mL with a LOD of 9 μU/mL for ECL mode, and 10 mU/mL to 200 U/mL with a LOD of 5.4 mU/mL for EC mode, was achieved. The proposed immunosensor was successfully employed for the detection of CA 15-3 in human serum without tedious pretreatment.

The effect of cellulose fibres in an epoxy adhesive for bonding wooden load-bearing elements

The work deals with the modification of the properties of epoxy adhesive. The modification consists of reinforcing this adhesive with cellulose fibres. In the field of wood glued elements, the current research focuses on the possibility of increasing the ductile behaviour of the epoxy adhesive, which would significantly increase the ability of the adhesive to transfer the stresses induced by the volumetric changes of the wood adherend. For this purpose, the adhesive was modified with fibres having a reinforcing character, which may include cellulose fibres. Due to the epoxy resin’s non-polar nature and the cellulose fibre's hydrophilic nature, which inhibits the fibre's homogeneous dispersion, the fibres have been modified with silanes. This paper describes the effect of adhesive modification by determination of tensile and shear strength at different amounts of filling and different types of silane pre-treatment of cellulose fibres. The optimum filling amount can be considered as 1.0% filling of nanofibrillated cellulose (NFC) with epoxy-functional silane pre-treatment.

Evaluation of the oligomeric epoxy silane as coupling agent on thermal and mechanical properties of water‐based acrylate adhesives

AbstractTo improve the thermal and mechanical properties of water‐based acrylate adhesives, epoxy functional silane oligomer (EFS) was investigated as a crosslinking agent at different curing temperatures from 100 to 140°C. Water‐based acrylate adhesives with different EFS concentrations (0.0–2.0 wt%) were prepared and characterized by Fourier transform infrared spectrometry (FT‐IR), colloidal stability, water absorption, mechanical and thermal properties. The thermal and mechanical properties of samples were investigated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile testing, Izod impact, and dynamic mechanical analysis. The amount of EFS had a significant influence on the crosslinking process and curing temperature. FT‐IR and TGA analysis revealed successful crosslinking of EFS with the water‐based acrylate adhesive at 100°C temperature. The use of EFS after different curing processes showed higher tensile strength and lower water absorption. Among the percentage of EPS studied, the use of 1.0 wt% presented the most promising results for the improvement thermal and mechanical properties. In addition, the results obtained in this study provide new insights into the use of EFS as a coupling agent of water‐based acrylate adhesives for wood‐fiber composites, as well as in the particleboard panels industry.

Bioinspired polydopamine deposition and silane grafting modification of bamboo fiber for improved interface compatibility of poly (lactic acid) composites

The surface of bamboo fiber (BF) has poor interface compatibility with the surface of the poly (lactic acid) (PLA), which compromises composite performance. In this study, a bioinspired polydopamine (PDA) function coating was constructed on a BF surface to act as a bridge to introduce an epoxy-functionalized silane layer (KH560). The results of the test confirmed that KH560 was successfully grafted onto the surface of the BF. Therefore, the flexural, tensile, and impact strength of the modified composites increased by 37.22%, 49.64%, and 26.66%, respectively, compared with that of the untreated composites. Furthermore, the PDA-KH560-modified BF enhanced the PLA composites’ thermal stability. This strategy is assumed to provide a simple and green method for improving interface adhesion strength and potentials for future manufacturing of high-performance composites.

Hydrophobic functionalization of cellulose nanocrystals for enhanced corrosion resistance of polyurethane nanocomposite coatings

A stiff, hydrophobic, and corrosion protective polyurethane (PU) nanocomposite coatings have been fabricated via the incorporation of surface modified cellulose nanocrystals (CNC). The modification of CNC involves surface grafting of varying levels of epoxy functionalized silane (ES). The effect of reaction time and concentration of ES on the level of grafting were evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), water contact angle measurement (WCA) and dispersibility test. It was found that prolonged reaction time and the high mole ratio of ES to CNC improve thermal properties and material wettability of the modified CNC. The incorporation of modified CNC in PU not only improved thermomechanical properties but also reduced the water absorption properties of the PU composites, which could be attributed to the improvement in the dispersion and enhanced interfacial adhesion between the nanoparticle and the PU matrix. Salt spray and electrochemical impendence spectroscopy (EIS) studies, which were carried out on mild steel coated with the fabricated nanocomposite (PU/ES-CNC), exhibited better anticorrosion behaviors as compared to PU. Overall, the CNC modification through silanization is a robust, eco-friendly, and scalable process, making it an appealing material for a range of polymer composite applications.

Epoxy-functionalized silane grafting enhances the cycling performances of Li1.2Ni0.13Co0.13Mn0.54O2 cathode materials

Epoxy-functionalized silane (KH560) modified Li1.2Ni0.13Co0.13Mn0.54O2 materials are prepared by a facile chemical grafting method for the first time. X-ray diffraction confirms that the crystal structure of Li1.2Ni0.13Co0.13Mn0.54O2 is not affected by the KH560 modification. Scanning electron microscopy and transmission electron microscopy results prove that KH560 is homogeneously grafted on the Li1.2Ni0.13Co0.13Mn0.54O2 surface with a thickness of 3–5 nm. The electrochemical tests reveal that the 1.0 wt% KH560 modified Li1.2Ni0.13Co0.13Mn0.54O2 cathodes retain 92.88% (1 C) and 98.24% (5 C) capacity retentions after 100 cycles, respectively, far higher than 83.09% (1 C) and 50.68% (5 C) of the pristine. The improved cycling performances are mainly attributed to the fact that the X-O-M bonds stabilize the surface oxygen and resist the parasitic reactions during cycling, which further can suppress the structure degradation and the impedance increase. This work provides a facile and effective modification method to optimize the interfacial structures of Li1.2Ni0.13Co0.13Mn0.54O2 and/or other cathode materials.

Reinforcing effect of aramid fibers on fatigue behavior of SBR/aramid fiber composites

This paper investigates the correlation between fatigue performance and static tensile behavior of fiber reinforced rubber materials and presents change of fiber reinforced effect during fatigue process. A rough aramid fiber (AF) surface, which is helpful for combining AF and rubber matrix, was achieved by etching AF in NaOH/CH3CH2OH solution via the hydrolysis of amide bonds on the fiber. Then, the treated fiber was coated with an epoxy-functionalized silane (γ-propyltrimethoxysilane, KH560) and was used to prepare AF/carbon black/styrene-butadiene rubber (AF/CB/SBR) composites. The results showed that the interfacial adhesion between the complex-modified AF and the rubber matrix was further enhanced and the mechanical properties of the composite were further improved compared with those of the composite which was prepared by unhydrolyzed AF coated with KH560. The hysteresis reinforcing effect of the fiber was found after 30,000 cycles of strain-controlled fatigue, and the reinforcing effect of AF was reduced with increasing average fatigue strain. Moreover, the relative debonding energy (RDE) was calculated to evaluate the reinforcing effect of the fiber, and the RDE value sharply decreased after 30,000 cycles of strain-controlled fatigue. When the AF was treated with the NaOH/CH3CH2OH solution and then coated with KH560, the rubber composite had a high RDE value, and the fatigue life of the composite under the stress-control condition was increased approximately 4 times. The results from the characterization of the fracture appearance after 30,000 cycles of fatigue showed that the composite with the complex-modified AF could maintain better interface bonding during the fatigue process.

Hygrothermal conditioning of wet-layup CFRP-concrete adhesive joints modified with silane coupling agent and core-shell rubber nanoparticles

The adhesive bond between externally bonded fiber-reinforced polymer (FRP) repairs and the concrete substrate can significantly deteriorate under hygrothermal conditions. The present study evaluated the epoxy adhesive toughening with core–shell rubber (CSR) nanoparticles and concrete surface functionalization with an epoxy-functional silane coupling agent as a means of improving the bond durability under hygrothermal exposure. To determine the effect of environmental degradation, beam bond test specimens were subjected to control conditions (standard laboratory conditions: 23 ± 2 °C and RH 50 ± 10%) and a hygrothermal accelerated conditioning protocol (ACP) (water immersion at 45 ± 1 °C) for 8 weeks. Bond test results indicate that CSR toughening and silane coupling agent can improve FRP-concrete adhesive bond strength retention following accelerated conditioning by up to 15% over that of neat epoxy. Following accelerated conditioning, CFRP coupons prepared with CSR-modified epoxy retain their mechanical properties, while the CFRP prepared with the neat epoxy exhibited a significant reduction in strength (40%) and elongation (54%). CSR nanoparticles demonstrated good compatibility with the base epoxy resin, as evidenced by differential scanning calorimetry (DSC) glass transition temperature measurements.

Design and Synthesis of Double-Functional Polymer Composite Layer Coating To Enhance the Electrochemical Performance of the Ni-Rich Cathode at the Upper Cutoff Voltage.

Graphene has been implemented as a desirable additive to improve the electrochemical performance of Ni-rich cathode materials. However, it is not only hard to ensure the intimate interaction between them in practice, which may affect the surface electronic conductivity of the composite, but also a challenge to fabricate cathodes with uniform graphene coating because of its two-dimensional planar structure. Besides, the graphene coating layer is easily peeled off from the cathode material during the cycling process, especially at the upper cutoff voltage. Therefore, we introduced a double-functional layer synergistically modified strategy to facilitate the electrochemical properties of LiNi0.8Co0.1Mn0.1O2 cathode materials. In the designed architecture, the LiNi0.8Co0.1Mn0.1O2 particles were uniformly enwrapped by a functional reduced graphene oxide (RGO)-KH560 polymer composite layer which consists of an inner high-flexibility epoxy-functionalized silane (KH560) layer and an outer RGO layer with high electronic conductivity. The KH560 layer, in the structural system, is especially critical in connecting the layer of outer RGO and the inner surface of the active material, which brings about the perfect and complete double-functional coating layer and in turn fully expresses the modification effect of both KH560 and RGO in the improvement of electrochemical performance. Consequently, higher capacity retention, better rate, and improved high-temperature performances (55 °C) at the upper cutoff voltage (4.5 V) of this composite are identified when compared with the RGO-coated and pristine samples. In particular, the cathode with RGO (0.5%)-KH560 (0.5%) coating exhibits capacity retentions of 95.2 and 81.5% after 150 cycles at 1 C, 4.5 V at room and high temperatures, respectively.

Toward Sustainable Multifunctional Coatings Containing Nanocellulose in a Hybrid Glass Matrix.

We report on a sustainable route to protective nanocomposite coatings, where one of the components, nanocellulose fibrils, is derived from trees and the glass matrix is an inexpensive sol-gel organic-inorganic hybrid of zirconium alkoxide and an epoxy-functionalized silane. The hydrophilic nature of the colloidal nanocellulose fibrils is exploited to obtain a homogeneous one-pot suspension of the nanocellulose in the aqueous sol-gel matrix precursors solution. The mixture is then sprayed to form nanocomposite coatings of a well-dispersed, random in-plane nanocellulose fibril network in a continuous organic-inorganic glass matrix phase. The nanocellulose incorporation in the sol-gel matrix resulted in nanostructured composites with marked effects on salient coating properties including optical transmittance, hardness, fracture energy, and water contact angle. The particular role of the nanocellulose fibrils on coating fracture properties, important for coating reliability, was analyzed and discussed in terms of fibril morphology, molecular matrix, and nanocellulose/matrix interactions.

Molecular design of confined organic network hybrids with controlled deformation rate sensitivity and moisture resistance

We demonstrate molecular design strategies for engineering the deformation rate sensitivity and fracture resistance of organic-inorganic hybrid films in moist environment. Hybrids with intimate mixing of inorganic and organic molecular networks were synthesized with an epoxy-functionalized silane, (3-glycidoxypropyl) trimethoxysilane and an acetate-stabilized zirconium alkoxide, tetra-n-propoxyzirconium. The highly confined non-hydrolysable organic molecular network connectivity was systematically manipulated by tuning the epoxy ring opening polymerization reaction and the incorporation of carbon bridges of selected lengths. By investigating the corresponding time-dependent crack growth in moist environments, new insights into the fundamental molecular-scale relaxation and cracking mechanisms of the hybrids are provided. These processes were found to be impacted by the confined organic network connectivity which results in significant changes in the deformation rate sensitivity and fracture resistance. With increasing non-hydrolysable organic network connectivity, mechanical behavior that varied from almost perfectly elastic to increasingly viscoelastic could be obtained in a controlled fashion. The related resistance to cracking in moist environments was found to be significantly improved. These findings provide a basis for the rational design of functional hybrids with precisely defined mechanical properties.

Novel organic–inorganic hybrid materials based on epoxy-functionalized silanes

Hybrid materials comprising inorganic glasses and organic polymers were investigated as potential replacements for diglycidyl ether of bisphenol-A to improve the thermomechanical properties of available composites. An epoxy-functionalized silane, 3-glycidoxypropyltrimethoxysilane (GPTMS), was employed to synthesize organic–inorganic hybrid materials (OIHMs) via a sol–gel process. The oxirane ring in GPTMS was cross-linked by compounds including an aliphatic amine, diethylenetriamine, amine-functionalized silane, n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, tertiary amine, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), and an acid anhydride, hexahydrophthalic anhydride. OIHMs derived from a difunctional organosilane, (3-glycidoxypropyl)methyldimethoxysilane, were also synthesized to compare the mechanical properties with OIHMs derived from GPTMS. Structural characterization of cured OIHMs was performed using a combination of attenuated total reflectance spectroscopy (FTIR-ATR) and 29Si solid-state nuclear magnetic resonance. Differential scanning calorimetry and thermogravimetric analysis were used to clarify the thermal properties. The thermomechanical properties and cross-link density were evaluated using dynamic mechanical thermal analysis (DMTA). In this study, it was evident that the presence of inorganic networks provided a significant improvement of the thermomechanical properties, where the glass transition temperature typically increases by 20 °C and the storage modulus at 150 °C by nearly eight times that of neat epoxy resin. An increase in glass transition temperature, end-use temperature, and the thermomechanical behavior of OIHMs was observed and quantified using DMTA. These results corresponded to calculated increases in cross-link density.

Research paper Application of epoxy functional silanes in the preparation of DNA microarrays

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Frydrych-Tomczak E, Uszczyńska B, Ratajczak T, et al. Application of epoxy functional silanes in the preparation of DNA microarrays. BioTechnologia. 2014;95(1):5-16. doi:10.5114/bta.2014.46408. APA Frydrych-Tomczak, E., Uszczyńska, B., Ratajczak, T., Markiewicz, W., Figlerowicz, M., & Nowicki, M. et al. (2014). Application of epoxy functional silanes in the preparation of DNA microarrays. BioTechnologia, 95(1), 5-16. https://doi.org/10.5114/bta.2014.46408 Chicago Frydrych-Tomczak, Emilia, Barbara Uszczyńska, Tomasz Ratajczak, Wojciech T. Markiewicz, Marek Figlerowicz, Marek Nowicki, and Hieronim Maciejewski et al. 2014. "Application of epoxy functional silanes in the preparation of DNA microarrays". BioTechnologia 95 (1): 5-16. doi:10.5114/bta.2014.46408. Harvard Frydrych-Tomczak, E., Uszczyńska, B., Ratajczak, T., Markiewicz, W., Figlerowicz, M., Nowicki, M., Maciejewski, H., and Chmielewski, M. (2014). Application of epoxy functional silanes in the preparation of DNA microarrays. BioTechnologia, 95(1), pp.5-16. https://doi.org/10.5114/bta.2014.46408 MLA Frydrych-Tomczak, Emilia et al. "Application of epoxy functional silanes in the preparation of DNA microarrays." BioTechnologia, vol. 95, no. 1, 2014, pp. 5-16. doi:10.5114/bta.2014.46408. Vancouver Frydrych-Tomczak E, Uszczyńska B, Ratajczak T, Markiewicz W, Figlerowicz M, Nowicki M et al. Application of epoxy functional silanes in the preparation of DNA microarrays. BioTechnologia. 2014;95(1):5-16. doi:10.5114/bta.2014.46408.

Durable Antifog Films from Layer-by-Layer Molecularly Blended Hydrophilic Polysaccharides

Mechanically durable, long-lasting antifog coatings based on polysaccharides were developed using a layer-by-layer (LBL) assembly process. The unique properties of these coatings are a result of a molecular-level blending of the polysaccharides, with multilayers containing chitosan and carboxymethyl cellulose providing the best overall properties. The antifog properties resulted from a strong interaction between the polar and H-bonding elements of the assembled polymers and water molecules and the concomitant formation of thin films of water. Environmental scanning electron microscopy (ESEM) studies confirmed that fogging coatings are decorated with light scattering, micrometer-sized droplets of water whereas antifogging coatings remain droplet free. To improve the mechanical durability of the multilayer films on substrates, the surface was modified via self-assembly of epoxy-functionalized silane molecules. Cross-linking chemistry was then applied to improve the mechanical robustness of the LBL films on various surfaces. These films were characterized using several techniques: optical profilometery (PL), spectroscopic ellipsometry (EL), contact angle goniometry (CA), and atomic force microscopy (AFM). The antifog properties of the films were evaluated by several tests under different environmental conditions. This work demonstrates that the unique water-adsorbing properties of polysaccharides can be exploited to create permanent antifog properties, which may be useful for various applications.

In situ fabrication of cross-linked PEO/silica reverse-selective membranes for hydrogen purification

Abstract Targeting at hydrogen purification, cross-linked organic–inorganic reverse-selective membranes containing poly(ethylene oxide) (PEO) are fabricated in situ by using functional oligomers (O,O′-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol: Jeffamine® ED-2003) with a high content of PEO and epoxy-functional silanes (3-glycidyloxypropyltrimethoxysilane: GOTMS). Changes in physicochemical properties due to varying silica content have been characterized; including a great decline in melting temperature; an improvement in glassy and degradation temperature, and the suppression of PEO crystallinity. The strong affinity between quadrupolar CO2 and polar ethylene oxide (EO) groups enhances the CO2/H2 separation performance of hybrid membranes, which can be further tuned by controlling the organic/inorganic ratio. The organic–inorganic hybrid membrane with 90 wt% of ED-2003 demonstrates an appealing CO2 permeability of 367 Barrer with an attractive CO2/H2 selectivity of 8.95 at 3.5 atm and 35 °C. The transport performance trend with composition variations is explained by analyzing the calculated solubility and diffusivity based on the solution-diffusion mechanism. Moreover, CO2 permeability increases with applied pressure in pure gas tests because of CO2 plasticization phenomena, which is beneficial for CO2/H2 separation. Attributing to CO2 plasticization and CO2 dominant sorption, the mixed gas test results of the membrane containing only 25 wt% ED-2003 show greatly improved CO2/H2 selectivity of 13.2 with CO2 permeability of 148 Barrer at 35 °C compared to pure gas results. Interestingly, at a stipulated CO2 pressure, the inherent tension in cross-linked networks maintains the CO2 permeability stable with the time. The cross-linked organic–inorganic membranes with enhancements in mechanical and thermal properties are promising for industrial-scale hydrogen purification.

Application of bilayer silanisation treatment to improve corrosion resistance and bond durability of aluminium alloy

In order to improve corrosion resistance and bond durability of AA2024-T3 alloy, a bilayer silanisation film layer on the Al alloy was prepared from two kinds of silanes, bis(3-(triethoxysilyl)-propyl)tetrasulphide (BTSPS, bis-sulphur silane) and γ-glycidoxypropyltrimethoxysilane (GPTMS, epoxy functional silane), by a two step process in this work. The bilayer film was characterised with infrared spectroscopy and transmission electron microscope (TEM), and composition depth profiles were performed by Auger electron spectroscopy (AES). The corrosion resistance and bond durability of the Al alloy of the bilayer silanisation pretreatment were assessed with potentiodynamic scan (PDS) and electrochemical impedance spectroscopy (EIS) as well as a wedge test respectively. The analytical results show that the corrosion resistance and bond durability of Al alloy of the bilayer silanisation treatment are superior to those of GPTMS silanisation.

Development and Characterization of Corrosion Resistant Coatings Using the Natural Biopolymer Chitosan

In the present study, chitosan was used as the basis for corrosion resistant coating. Chitosan suffers from two inherent weaknesses as a coating material namely high hydrophilicity and poor adhesive strength with Al 2024 T3 alloy. In the present study, chitosan structure was modified using epoxy functional silane and vanadate. Performance of coatings was tested using EIS, adhesion testing and salt spray testing. The best salt spray performance was observed in case of chitosan-(3-Glycidoxypropyl)-trimethoxysilane-vanadate coatings, which lasted 450 hours in salt spray chamber. UV/Visible measurements showed release of vanadate by chitosan increases with increasing solution pH. This property of chitosan provides self-healing characteristics to these coatings. When the solution pH is readjusted to a lower value, chitosan can re-adsorb released vanadate. FTIR spectra of chitosan gel showed adsorption of vanadate at protonated amine sites. Chitosan showed a maximum in the vanadate adsorption capacity in the pH 3 to 5 range.

Characterization of sizing layers and buried polymer/sizing/substrate interfacial regions using a localized fluorescent probe

A novel technique is described to investigate buried polymer/sizing/substrate interfacial regions, in situ, by localizing a fluorescent probe molecule in the sizing layer. Epoxy functional silane coupling agent multilayers were deposited on glass microscope cover slips and doped with small levels of a fluorescently labeled silane coupling agent (FLSCA). The emission of the grafted FLSCA was dependent on the silane layer thickness, showing blue-shifted emission with decreasing thickness. The fluorescent results suggest that thinner layers were more tightly bound to the glass surface. The layers were also characterized by scanning electron microscopy, contact angle, and thermogravimetric analysis (TGA). When the FLSCA-doped silane layers were immersed in epoxy resin, a blue shift in emission occurred during resin cure, indicating the potential to study interfacial chemistry, in situ. Thicker silane layers exhibited smaller fluorescence shifts during cure, suggesting incomplete resin penetration into the thickest silane layers.