Methyltrimethoxysilane Research Articles

Experimental Studies on Abrasion Wear and Thermal Characteristics of Plain Derived Flax Woven Fabric Reinforced Epoxy Composites

ABSTRACT Nowadays, natural plant fibers are being explored and employed for various industrial applications owing to their attributes such as low weight to strength ratio, cost effectiveness, biodegradability and environment-friendliness. In this work, alkali and trimethoxymethyl silane (ATS) treated plain derived irregular basket woven flax fabric-reinforced epoxy composites (F-E) namely 0-TFE (Neat epoxy), 25-TFE, 35-TFE and 45-TFE with 0, 25, 35 and 45 wt.% fiber contents respectively were prepared by compression molding at room temperature, and studied for their abrasive wear and thermal degradation characteristics as per the standard procedures. Abrasive test was performed on pin on disc with a track diameter of 80 mm (ASTM G-99-05) for varying applied load and different abrasive grits condition for a constant speed of the disc. Wear outcome revealed that wear loss, specific wear rate (SWR) and coefficient of friction (COF) were influenced by the combined effect of applied load and abrasive grits. The composite 45-TFE exhibited better tribological properties amongst the prepared lot. Furthermore, thermal analysis revealed that the fabricated F-E composites are sufficiently thermally stable for structural applications and ATS treated- plain derived flax woven reinforcement enhanced the thermal stability. Scanning electron microscopy (SEM) was used to understand the wear mechanisms of composites.

Synthesis, Characteristics, Oil Adsorption, and Thermal Insulation Performance of Cellulosic Aerogel Derived from Water Hyacinth.

Cellulosic aerogel from water hyacinth (WH) was synthesized to address the dual environmental issues of water hyacinth pollution and the production of a green material. Raw WH was treated with sodium hydroxide (NaOH) with microwave assistance and in combination with hydrogen peroxide (H2O2). The results from X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) showed that lignin and hemicellulose were markedly decreased after treatment, reducing from 24.02% hemicellulose and 5.67% lignin in raw WH to 8.32 and 1.92%, respectively. Cellulose aerogel from the pretreated WH had a high porosity of 98.8% with a density of 0.0162 g·cm–3 and a low thermal conductivity of 0.030 W·m–1·K–1. After modification with methyl trimethoxysilane (MTMS) to produce a highly hydrophobic material, WH aerogel exhibited high stability for oil absorption at a capacity of 43.3, 43.15, 40.40, and 41.88 (g·g–1) with diesel oil (DO), motor oil (MO), and their mixture with water (DO + W and MO + W), respectively. The adsorption remained stable after 10 cycles.

Removal of Oil Pollution in water using hydrophobic silica

Nowadays the contamination in waters by oily substances turns out to be a problem of world-wide scope and although some methods of removal of oils in water exist; these present some limitations; therefore, this project proposes the use of hydrophobic silicas as absorbent materials for oily substances. Modified silicas (R-SiO2) were synthesized using the Stöber method, modifying the surface by co-condensation. Tetraethyl-orthosilicate (TEOS) and two surface modifiers were used as silica former: Methyl-trimethoxysilane (MeTEOS) and n-octyl-triethoxysilane (nOctyl-TEOS). The R-SiO2 were characterized by infrared spectroscopy identifying the modifying groups and their hydrophobicity was qualitatively evaluated according to the change in solubility in water. Finally, the removability of an automotive motor oil was evaluated by determining the amount of oil removed per gram of modified silica.

Trimethoxymethylsilane as a solid-electrolyte interphases improver for graphite anode

To improve the cycling performance of graphite anode materials, we propose a functional electrolyte additive, trimethoxymethylsilane (TMSi), which contains a silyl ether functional group as part of its molecular structure. First principal calculation studies, in addition to ex situ analyses, demonstrated that electrochemical reduction of ethylene carbonate (EC) gives an anionic reduced EC product. Subsequent chemical reaction with TMSi then generates solid-electrolyte interphase (SEI) layers of Si–O and Si–C functionalized carbonate on the surface of the graphite anode, which prolongs and stabilizes the cycling performance of the cells. As a result, the cell cycled with TMSi-controlled electrolyte exhibits a cycling retention of 89.5%, whereas the cell cycled with standard electrolyte suffers from poor cycling retention (84.3%) after 100 cycles.

Wettability alteration and retention of mixed polymer-grafted silica nanoparticles onto oil-wet porous medium

Enhanced oil recovery (EOR) processes are applied to recover trapped or residual oil in the reservoir rocks after primary and secondary recovery methods. Changing the wettability of the rock from oil-wet to water-wet is named wettability alteration. It is an important factor for EOR. Due to their unique properties, nanoparticles have gained great attention for improving oil recovery. Despite the promising results, the main challenges of applying nanoparticles are related to the colloidal stability of the nanofluids in the harsh conditions of the reservoirs. In recent years, polymer-grafted nanoparticles have been considered as novel promising materials for EOR. The obtained results showed that adding a hydrophobic agent trimethoxy (propyl) silane on the surface of modified silica nanoparticles with polyethylene glycol methyl ether has an effective role in improving retention and wettability alteration, especially in the oil-wet substrate due to hydrophobic interaction. The modified silica nanoparticle by mixed polyethylene glycol methyl ether (Mn ~ 5000) and trimethoxy (propyl) silane showed a proper performance at a concentration of 1000 ppm and a salinity range of 2000–40,000 ppm. The obtained findings can help for a better understanding of the silica nanofluid modification with both hydrophilic and hydrophobic agents for the EOR application of near-wellbore.

Effects of additives in colloidal silica based inorganic-hybrid binder for mineral wool insulation boards

ABSTRACT In the mineral insulation board industry, it has been a challenge to replace the current organic binder to eco-friendly inorganic binder to enhance the fire-resistance, and reduce toxicity. Inorganic and hybrid (organic-inorganic) type materials are often used, but the effects of these binders on the properties of the insulation board are little understood when applied to ceramic wool. In this study, silica-sol base binders with additives such as fumed silica, silicates, methyltrimethoxy silane, or polysiloxane are utilized. The inorganic-hybrid binders are used to understand how they change the microstructure, and how these changes in microstructure influence the insulation board properties. The effects of (i) the morphology of silica, (ii) adding alkali-silicates, and (iii) adding network modifiers are investigated for silica-sol type binders by assessing properties of fabricated boards, such as thermal conductivity, compressive strength, and water absorption rate. In particular, for a binder of colloidal silica with silicate and polysiloxane, we found that this binder forms clot-like hubs at junctions while embedding fibers. Thus, this structure allows the insulation board to withstand higher compression stress while having equivalent thermal insulation and waterproof performance as a phenolic binder.

Control of temperature changes in daily life with thermochromic green pigments

In this study, intelligent thermochromic building coatings were prepared to reduce the heating and cooling load of the building by creating a thermally comfortable building environment. Reversible effects of thermochromic building coatings between energy absorber, energy reflective states were investigated. Methyltrimethoxysilane (MTEOS), tetraethoxysilane (TEOS), thermochromic pigment-based thermochromic coatings were prepared with the sol–gel spraying method. Coatings were heat-treated at 80 °C and characterization studies were performed. It has been determined that the sample contains the silicon oxide and amorphous phase. The average grain size of the sol was found to be 6.021 μm. The development of thermochromic coatings to be utilized in buildings, urban structures were aimed. Coatings obtained in a low-cost manner exhibited thermochromic properties. The resulting coatings provided good temperature sensitivity, reversibility.

Effects of Phenyltrimethoxysilane and Polyvinyl Alcohol on the Properties of Methyltrimethoxysilane-based Silica Aerogels

Silica aerogels have attracted great attention owing to their outstanding properties such as ultralow density, high porosity, high surface area, and low thermal conductivities. Their poor mechanical properties and hydrophilicity constrain their practical applications. In this work, phenyltrimethoxysilane (PTMS) and polyvinyl alcohol (PVA) were added into methyltrimethoxysilane (MTMS)-based silica aerogels to enhance their mechanical properties. It was found that PTMS considerably improved the hydrophobicity of MTMS silica aerogels with an increase in water contact angles from 115° to 150°. The addition of PVA considerably increased the hardness, morphology, density, porosity, surface area, and thermal conductivity of MTMS silica aerogels. When PVA concentration was increased from 0 to 2 %, the aerogel hardness, density, and thermal conductivity were also increased from 0 to 14 %, 0.072 to 0.11 g/cm3, and 0.035 to 0.046 W/m.K. In contrast, the aerogel became less porous and the porosity reduced from 97.2 % to 95.72 % and BET surface area decreased from 389 to 43 m2/g.

Composite Aerogel for Heat Insulation

Silica aerogels are often brittle and MTMS is rather expensive. Therefore, it is necessary to strengthen MTMS silica aerogels and lower their cost. In this research, hydrophobic composite monolithic methyltrimethoxysilane (MTMS) based aerogels were investigated. The aerogels were synthesized by an acid base sol-gel process with solvent exchange and freeze drying. Silica extracted from rice husk ash, poly vinyl alcohol (PVA) and glass wool were combined with MTMS to form the composite aerogels, whose microstructure, thermal property and hydrophobicity were evaluated. The aerogels were found to have thermal conductivity as low as 0.032 W/m.K and water contact angle as high as 152.2°.

Photoelectrocatalytic evaluation of EG-CeO2 photoanode on degradation of 2,4-dichlorophenol

Herein, we report the photoelectrocatalytic degradation of 2,4-dichlorophenol as a model chlorinated phenolic compound on exfoliated graphite-cerium(IV) oxide (EG-CeO2) photoelectrode. The EG-CeO2 nanocomposites with and without trimethoxymethylsilane (TMOMS) were synthesized using impregnation ultrasonic agitation and comprehensively characterized by XRD, FTIR, Raman, TGA, DSC, FESEM, TEM, EDS, UV–Vis DRS, BET, XPS, and AFM. The SEM results revealed that the CeO2 material was entrapped within the cavities and on the surface of EG sheets. Electrochemical studies were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). Photoelectrocatalytic degradation of 2,4-dichlorophenol dissolved in 0.1 M Na2SO4 electrolyte was performed with chronoamperometric technique. The EG-CeO2 (TMOMS) displayed higher removal efficiency under simulated light compared to EG and EG-CeO2, respectively. The degradation efficiency of 98.7% was attained with EG-CeO2 (TMOMS) under optimum conditions of pH 6.2 and current density of 8 mA cm−2. Total organic carbon removal of about 92.6% was recorded during the degradation of 2,4-DCP under optimum conditions for 180 min. Based on the results obtained, the low-cost EG-CeO2 (TMOMS) photoelectrode has lent itself into possibility of photoelectrocatalytic degradation of organic water pollutants and can be extended to environmental samples application.

Ultralight Industrial Bamboo Residue-Derived Holocellulose Thermal Insulation Aerogels with Hydrophobic and Fire Resistant Properties.

In this study, water-soluble ammonium polyphosphate- (APP) and methyl trimethoxysilane (MTMS)-modified industrial bamboo residue (IBR)-derived holocellulose nanofibrils (HCNF/APP/MTMS) were used as the raw materials to prepare aerogels in a freeze-drying process. Synthetically modified aerogels were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and thermal stability measurements. As-prepared HCNF/APP/MTMS aerogels showed themselves to be soft and flexible. The scanning electron microscopy (SEM) analysis showed that the foam-like structure translates into a 3D network structure from HCNF aerogels to HCNF/APP/MTMS aerogels. The compressive modules of the HCNF/APP/MTMS aerogels were decreased from 38 kPa to 8.9 kPa with a density in the range of 12.04–28.54 kg/m3, which was due to the structural change caused by the addition of APP and MTMS. Compared with HCNF aerogels, HCNF/APP/MTMS aerogels showed a high hydrophobicity, in which the water contact angle was 130°, and great flame retardant properties. The peak of heat release rate (pHRR) and total smoke production (TSP) decreased from 466.6 to 219.1 kW/m2 and 0.18 to 0.04 m2, respectively, meanwhile, the fire growth rate (FIGRA) decreased to 8.76 kW/s·m2. The thermal conductivity of the HCNF/APP/MTMS aerogels was 0.039 W/m·K. All results indicated the prepared aerogels should be expected to show great potential for thermally insulative materials.

Preparation of Superhydrophobic Porous SiO₂ Aerogel Using Methyl Trimethoxy Silane Single Precursor and Superhydrophobic Cotton Fabric Coating from It.

Superhydrophobic cotton fabrics were prepared by simultaneous incorporation of SiO₂ aerogel particles and polydimethylsiloxane (PDMS). The SiO₂ aerogels were synthesized via acid-base catalyzed sol-gel reaction with methyl trimethoxy silane (MTMS) as the single precursor and oxalic acid and ammonium hydroxide as the catalyst in methanol (MeOH) solution by drying under ambient pressure. The preparation parameters (e.g., MTMS/MeOH molar ratio, oxalic acid/MTMS molar ratio, gelation pH value, and gelation temperature) had great influences on the density and porosity of the SiO₂ aerogel. The obtained SiO₂ aerogel had low density, high porosity and high specific surface area, showing the typical rough mesoporous structure. The prepared bulk SiO₂ aerogel displayed excellent superhydrophobicity with a water contact angle (WCA) of 151.0 ± 0.8°. Superhydrophobic cotton fabric with a WCA of 155.6 ± 0.9° for a 5 μL water droplet was successfully obtained by simply coating the PDMS/SiO₂ aerogel composite solution via dip-pad-cure process. This could be attributed to the combination of SiO₂ aerogel particles with porous rough microstructure, high specific surface area and PDMS adhesive layer with low surface energy. The effect of PDMS/SiO₂ aerogel coating treatment on the mechanical strength properties of the cotton fabrics was negligible. This simple approach may pave the potential way for practical applications.

Synthesis of nano-TiO2 coating systems for solar cell

PurposeThe purpose of this paper is to implement coating system by varying the amount of nano-sized titanium dioxide, (nano-TiO2) combined with various organic binders and to study the coating effects on the performance of solar cell in terms of temperature and efficiency.Design/methodology/approachNano-TiO2 coatings are developed in two types of binder networks; the combination of methyltrimethoxy silane (MTMS) and nitric acid and the combination of 3-aminopropyl triethoxysilane (APTES) and MTMS. Overall, the formulations method was cost-effective, produces good transparency, clear and managed to dry at room temperature. The coating mixtures were applied onto the glass substrate by using the dip-coating method and the coated substrate were sent for several characterizations.FindingsThis study demonstrated that TiO2 nanoparticle coating in APTES/MTMS matrix showed a thermal-decreasing result on solar cells, where the cell temperature is reduced to 46.81°C (T2 coating type) from 55.74°C (without coating) after 1-h exposure under 1,000 W/m2 irradiance in a solar simulator. Contrary to prior works where solar cell coatings were reported to reduce the cell temperature at the expense of the cell efficiency, the results from this study reported an improved fill factor (FF) of solar cells. From the photovoltaic (PV) characteristics study, the FF for solar cells is increased by approximately 0.2, i.e. 33.3 per cent, for all coatings compared to the non-coated cell.Research limitations/implicationsFindings will be able to contribute in the development of temperature-reducing and efficiency-enhancing coating for PV panels.Practical implicationsA simple dip-coating method provides an even distribution of TiO2 nanoparticle coating on the glass panel, which is cost-effective and time-efficient to reduce the temperature of solar cell while maintaining its efficiency.Originality/valueThe ability of nano-TiO2 coatings with a simple fabrication method and the right solution to reduce the surface temperature of solar cells while improving the FF of the cells.

Chemical modification of hemp fibres by plasma treatment for eco-composites based on biodegradable polyester

In this paper, raw hemp fibres were used to reinforce a commercial biopolyester, namely poly(1,4-butylene adipate-co-terephthalate), to achieve eco-composite materials. To promote the adhesion between the polyester matrix and the fibrous reinforcement, chemical modification of fibres surface with coupling agents was accomplished. Usually, the grafting of coupling molecules is carried out involving high amount of solvents. Here, in a general approach of an environmental sustainability, uncut, combed and slightly stretched hemp fibres were treated with a green process based on a novel soft plasma jet device (developed by Nadir Srl). This technique activates the fibres surface and, at the same time, allows the deposition of reactive monomers as coupling agents. Three different monomers were investigated: methyl methacrylate (MMA), (3-aminopropyl)triethoxysilane (APTES) and (3-glycidyloxypropyl)trimethoxysilane. Unmodified and surface-modified fibres were characterized and compared in terms of thermal behaviour and morphological features. Long-fibre eco-composites were then prepared by different compression moulding procedures and characterized by thermal, morphological and dynamic mechanical analysis. Experimental evidences indicated that the cold plasma deposition/grafting treatment was successfully carried out; the composite with the best mechanical performance resulted that obtained by using APTES as coupling agent.

Structural evolutions and oxidation behavior of Fe-doped silicon oxycarbide nanocomposites at medium temperatures

A novel Fe ion doped silicon oxycarbide (SiFeOC) ceramic was prepared by solvothermal method using methyltrim ethoxysilane, dimethyl dimethoxy silicane, and ferric nitrate as raw materials. Compared with pure SiOC ceramic, the incorporation of Fe ion into SiOC ceramic significantly enhanced phase separation of the SiOC network. Transmission electron microscopy and X-ray diffraction analysis showed that the SiFeOC ceramics were made up of amorphous SiOC, SiC and Fe3Si phases after pyrolysis at 1573 K. The anti-oxidation capabilities of such nanocomposites were also investigated at medium temperatures. Results showed that SiFeOC ceramics had better oxidation resistance properties than pure SiOC ceramics, and the phase compositions of those samples were also analyzed after the oxidation test process. This work provides a guidance to fabricate metal-modified SiOC ceramics with desired structures.

Identification of Protonated Primary Carbamates by Using Gas-Phase Ion–Molecule Reactions Followed by Collision-Activated Dissociation in Tandem Mass Spectrometry Experiments

The levels of potentially mutagenic impurities (PMIs) in active pharmaceutical ingredients are highly regulated and must be below a critical safety threshold. One class of PMIs is primary carbamates, which are formed during drug manufacturing and formulation. To comply with safety regulations, it is critically important to develop analytical techniques that enable the identification of primary carbamates during the drug development process. In this study, tandem mass spectrometry combined with gas-phase ion–molecule reactions as well as collision-activated dissociation (CAD) is demonstrated to enable the identification of protonated primary carbamates. Primary carbamates were protonated via atmospheric pressure chemical ionization (APCI) in a linear quadrupole ion trap mass spectrometer, isolated, and allowed to react with trimethoxymethylsilane (TMMS) introduced into the ion trap via an external reagent mixing manifold. Protonated primary carbamates reacted with TMMS to form an adduct ion, [M + H + TMMS]...

Spin-coated polymer composite hydrophobic surfaces with self-cleaning performance

Hydrophobic surfaces can be developed with low surface energy materials as per the Wenzel state. To intensify the adherence of the coating on the substrates, polymer has been employed in the coating. The Polymer-silica coating has been prepared with the help of PMMA (Poly methyl methacrylate), PS (Polystyrene) and MTMS (Methyltrimethoxy silane) in the study. Composite of PMMA/MTMS and PS/MTMS were coated uniformly on the substrates by spin-coating technique at a speed of 1500 and 1300 rpm. The functional groups have been identified with Fourier Transform Infrared Ray Spectroscopy. Property of low surface energy (ϒ), for hydrophobic surface can be evolved, with Hamaker’s constant (AH), Vander Waals interaction between the particles of opposite surface charge which form permanent dipoles. The contact angle for PMMA/MTMS is 112° and PS/MTMS is 119° is measured. Further, the optical and structural properties were designated by UV-Visible spectroscopy and FESEM. The particles of dust on the coated surface rolls off smoothly upon contact with the water droplet ensuring the self-cleaning nature.

Lipophilic magnetic nanocomposite of Fe3O4@SiO2@Me for efficient visualization of latent fingerprints on various surfaces

This study intends to design and prepare a new magnetic nanopowder as a quasi-chemical dusting agent for the development of latent fingerprints (LFPs) on various surfaces. Tuning of the nanopowder properties between chemical and physical fingerprint agents was performed by investigation of surface lipophilicity influence on the visualization of latent fingerprints. For this purpose, trimethoxymethylsilane (TMMS) was used to modify Fe3O4@SiO2 core–shell magnetic nanoparticles to obtain a lipophilic, selective, and efficient magnetic nanopowder for detecting LFPs. Various analytical techniques were used to characterize the nanoparticles to show that the achieved structures and properties are well-suited for forensic science. Finally, fingerprints developed using the Fe3O4@SiO2@Me nanopowder were applied on several porous and nonporous surfaces. The Fe3O4@SiO2@Me new lipophilic fingerprint nanopowder offers simple synthesis process, convenient use for routine casework and low price.

Phase Behavior of a Carbon Dioxide/Methyl Trimethoxy Silane/Polystyrene Ternary System.

Recently, polymeric foams filled with a silica aerogel have been developed. The phase behavior of CO2/silicon alkoxide binary systems and CO2/silicon alkoxide/polymer ternary systems is an important factor that affects the design of novel processes. The phase behavior of a carbon dioxide (CO2)/methyl trimethoxy silane (MTMS)/polystyrene (PS) ternary system was measured using a synthetic method involving the observation of the bubble and cloud point. The phase boundaries were measured at temperatures ranging from 313.2 to 393.2 K and CO2 weight fractions between 0.01 and 0.08. The CO2/MTMS/PS system showed a similar CO2 mass fraction dependence of the phase behavior to that observed for the CO2/tetramethyl orthosilicate (TMOS)/PS system. When the phase boundaries of these systems were compared, the vapor-liquid (VL) and vapor-liquid-liquid (VLL) lines were found to be nearly identical, while the liquid-liquid (LL) lines were different. These results indicate that the affinity between the silicon alkoxide and polymer greatly influences the liquid-liquid phase separation.

Preparation of Non-Fluorinated Water Repellent Coating Films Using Methyltrimethoxysilane and Trimethylethoxysilane

Methyltrimethoxysilane (MTMS)과 trimethylethoxysilane (TMES)을 전구체로 사용하여 비 불소계 발수 코팅 용액을 제조하였다. 이 코팅 용액을 냉연 강판 위에 스핀 코팅하고 열 경화시켜 발수 코팅 도막을 제조 하였다. 이 과정 중 코팅 도막의 소수성에 미치는 TMES/MTMS의 몰 비 영향이 연구되었다. 코팅 도막의 소수성은 접촉각 측정, 표면 형상 분석 및 적외선 분광법을 사용하여 연구되었다. TMES/MTMS의 몰 비를 0에서 30까지 변화 시켰을 때, 코팅되지 않은 냉연강판의 접촉각은 30˚인 반면에 TMES/MTMS의 몰 비가 1인 경우는 접촉각이 104°로 크게 증가하여 발수성이 향상되었다. 또한 TMES/MTMS의 몰 비가 10, 15, 25, 30인 경우는 각각 접촉각이 109o, 114°, 117°, 144°로 TMES/MTMS의 몰 비가 증가할수록 냉연강판의 접촉각이 점차 증가하는 경향을 보였다. 이때 코팅 도막의 소수성은 표면 거칠기의 증가와 코팅 표면에서의 메틸 성분의 함량 증가로 인해 향상되었다. 특히 TMES/MTMS의 몰 비가 30인 경우에는 TMES의 메틸기로 인한 발수성뿐만 아니라 표면 입자의 존재로 인해 전체적인 표면 거칠기가 크게 증가하였기 때문에 144°의 초발수성을 나타내었다.