Chloropropyl Trimethoxysilane Research Articles

Structure and properties of in situ reactive blend of polylactide and thermoplastic starch

In this study, in situ reactive extrusion of polylactide and thermoplastic starch modified with chloropropyl trimethoxysilane coupling agent (PLA/mTPS) is proposed. The success of covalent bond formation between PLA matrix and mTPS phase is clarified by two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy with 1H1H TOCSY mode. This chemically bound PLA with starch gives the remarkable compatibility in the PLA/mTPS film, with not only a decreased glass transition temperature (47 °C) but also an increased crystallinity of PLA (Χc of 50%). It consequently increases oxygen barrier significantly and also enhances the film flexibility as observed from the drastic increase of elongation at break (from 3% to 50%). Moreover, the PLA/mTPS 60/40 (w/w) film exhibits the accelerated degradation as compared with pure PLA film.

Synthesis and characterization of enhanced silica nanoparticle (SiO2) prepared from rice husk ash immobilized of 3-(chloropropyl) triethoxysilanea

Rice Husk Ash (RHA) is the by-product for rice mill industry and it is considered as waste material. It is considered a way to recycle materials, which is one of the types of renewable energy. Many types of research focused on RHA are targeting the high contain Sodium silicate. Sodium silicate to be converted to silica. The sol–gel technique offered a simple route in producing silica Rice husk ash immobilized with 3-(chloropropyl) trimethoxysilane (RHACCl) from RHA, where 3-(chloropropyl) trimethoxysilane (CPTES) is used to reduce the RHA into high-quality silica nanoparticle. Silica produced from this technique is found to have the presence of carbon; silicon and chlorine were determined by a combination of elemental analysis by EDX. UV–visible absorbance spectra of the RHACCl NPs silica samples having a wavelength of 333 nm showing absorbance in the ultraviolet region. FTIR spectroscopy scanning electron microscopy (FESEM) and energy dispersive spectrometry. The spectral proof obtained in this research showed that CPTES was installed on the SiO 2 surface. The reaction was successful through the presence of chlorine ion, which is considered an important organic function, and the presence of chlorine in the amorphous SiO 2 is an important starting point to developing the wide range from silica-based materials.

Synthesis of silica coated on iron sand magnetic materials modified with 2- mercaptobenzimidazole through sol-gel

Synthesis of silica coated on iron sand magnetic materials modified with mercapto was carried out through a sol-gel method. This study aims to obtain adsorbent material that has magnetic properties. The purpose of this research are gift magnetic proprties of adsorbent. It was easy access to the separation of the adsorbent after the adsorption process in aqueous system. Modified silica surface with mercapto group provides spesific and selective for soft metals according to hard soft acid base (HSAB) principle. Solution of Na 2 SiO 3 as a silica precursor were coated on the surface of iron sand magnetic materials (MM) that has been activated by acid. Silica which have been coated on MM then modified with compound 2- mercaptobenzimidazole as a functional group of mercapto (-SH). The compound 2- mercaptobenzimidazole does not have a functional group of silanol (≡Si-OH) and siloxane (Si- O-Si) to bind to the functional group on silica surface. Therefore, chloropropyltrimethoxysilane (CPTMS) was added as a link between silica and 2-mercaptobenzimidazole. Chloropropyltrimethoxysilane (CPTMS) was reacted with 2-mercaptobenzimidazole as mixture I then mixed into silica which has coated MM as mixture II by sol-gel process. Material characterization was carried out by Fourier Transform Infrared (FTIR) spectrophotometer, X- ray diffractometer (XRD) and Vibrating Sample Magnetometer (VSM), and the stability of coated magnetite against acid. The characterization results showed that synthesized adsorbent of MM/SiO 2 /SH was successful. Coating of iron sand magnetic material with silica modified mercapto increases the stability of the acid and decreases the magnetic properties.

QGO enhanced PET fibre for multi‐applications

Graphene oxide (GO) is grafted to chloropropyl trimethoxysilane, then it is grafted from N , N -dimethyldodecylamine to prepare a quaternised GO (QGO). The QGO is introduced to polyester (PET) fibre surface by immersion method. The results show that the QGO possesses good dispersibility, antibacterial activity and durability, the antibacterial rate of QGO-modified PET fibre against Staphylococcus aureus, Escherichia Coli and Bacillus subtilis are 99.5, 99.5 and 99.8%, respectively. In addition, the QGO-modified PET fibre shows a good chemical stability and corrosive resistance. It is convenient for preparing wearable textiles.

Silane Modification of Starch-Based Wood Adhesive: Review

Currently there has been a growing interest in substituting traditional synthetic polymers with biobased renewable polymers for adhesive applications. However, biobased renewable polymers such as starch suffer from few draw-backs like poor water resistance and mechanical strength. To become important potential alternatives of synthetic polymers, starch must have comparable physical, chemical, thermal and mechanical properties to that of synthetic polymers. To achieve this, starch has been modified by a series of crosslinkers like boric acid, citric acid, glyoxal, gluteraldehyde, etc. and silane modification. Silane modification by chloropropyl trimethoxysilane, γ-Methacryloxypropyl trimethoxy silane and vinyl trimethoxy silane is a suitable method to improve the performance in terms of mechanical and thermally. Silane forms covalent bonds with starch during starch modification resulted in enhanced shear strength and storage stability. A new research on biodegradable, renewable, environmentally friendly silane modification of starch-based wood adhesive that was prepared by reacting with various silanes. This paper, we reviewed silane as a modifying agent for starch-based wood adhesive.

Quantum chemical studies on the inhibitive effect of silane derivatives

The correlation between the molecular structure and corrosion inhibition of silane derivatives including 3-mercaptopropyltrimethoxysilane (PropS-SH), dodecyltrimethoxysilane (DTMS), 3-aminopropyl(trimethoxy)silane (APS) and chloropropyl (trimethoxy)silane (CPTMS) was investigated by density functional calculations. It is found that the atoms O, C connected with Si atoms and terminal functional groups in silane molecules are active adsorption sites. The functional groups attached to the alkoxy carbon chain have an influence on the overall reactivity of the silane molecules. The PropS-SH molecules has the least energy gap and the highest reactivity, and therefore has the highest inhibition efficiency among the investigated inhibitors.

Heterogeneous complexes of nickel MCM-41 with β-diimine ligands: Applications in olefin oligomerization

The β-diimine ligands 2-(phenyl)amine-4-(phenyl)imine-2-pentene and 2-(2,6-dimethylphenyl)amine-4-(2,6-dimethylphenyl)imine-2-pentene were combined with the alkoxysilane group chloropropyltrimethoxysilane (CPTMS) and covalently anchored to a mesoporous MCM-41 support; they were ordered via interactions with the silanols of the silica matrix and complexed with nickel. The complexes were synthesized for use in ethylene and propylene oligomerization and for comparing the results of homogeneous and heterogeneous systems. The support was first synthesized, calcined, anchored to the ligand, and then, complexed with nickel. These materials were characterized using various techniques, such as 1H, 13C, and 29Si NMR, small angle XRD, thermogravimetric analysis, adsorption isotherms, transmission electron microscopy, and flame atomic absorption spectroscopy, to confirm the success of the synthesis. Both homogeneous and heterogeneous complexes are active and selective for the reactions of ethylene and propylene oligomerization.

Immobilized VOsalpr on modified Fe3O4 nanoparticles as a magnetically separable epoxidation catalyst

Fe 3 O 4 nanoparticles were prepared and modified with chloropropyl trimethoxysilane (Cl-PTMS). The N , N′ -bis(3-salicylidenaminopropyl)amine (salpr) Schiff base ligand was then immobilized on modified Fe 3 O 4 , which was followed by the addition of VOSO 4 in order to complex it with immobilized sa0lpr. The obtained nanocatalyst designated as VO(Salpr)/SCMNPs was characterized by FT–IR, XRD, SEM, TEM, and VSM techniques. It was found that VO(salpr)/SCMNPs successfully catalyze the epoxidation of allyl alcohols, such as limonene, 1-octene-3-ol, trans -2-hexene-1-ol and geraniol with 50 to 100% conversion and 62 to 100% selectivity with tert -butylhydroperoxide (TBHP). The study of this catalyst's stability and reusability revealed that VO(salpr)/SCMNPs behaves heterogeneously with no desorption during the course of the epoxidation reactions.

Efficient Synthesis of 2-amino-4H-chromene Derivatives in the Presence of Piperazine-functionalized Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub> Magnetic Nanoparticles as a New Heterogeneous Reusable Catalyst Under Solvent-free Conditions

A new piperazine-functionalized Fe3O4/SiO2 magnetite nanoparticle was synthesized through the surface modification of magnetic iron oxide nanoparticles by piperazine. Iron oxide nanoparticles were synthesized by coprecipitation method and the surface modification process was achieved by treating the nanoparticles with tetraethyl orthosilicate (TEOS), chloropropyl trimethoxy silane (CPTS) and piperazine. The developed functionalized iron oxide nanoparticle was evaluated as a reusable heterogeneous organobase catalyst for the synthesis of 4H-chromene derivatives from multi-component condensation reaction of 2-naphthol, malononitrile and aldehydes under solvent-free conditions. To receive morphological and structural information on the as-prepared catalyst, the samples were investigated by various techniques such as FT-IR, TEM, XRD, vibrating sample magnetometry (VSM), TGA and elemental analyzer. Under appropriate conditions, all reactions afforded the desired products in good to excellent yields. Moreover, this catalyst can be easily recovered by using a magnetic field and directly reused for at least six runs without significant loss of its activity.

Silane modified starch for compatible reactive blend with poly(lactic acid)

A reactive blend of poly(lactic acid) (PLA) and a surface modified starch by silane coupling agent to achieve compatibility is proposed. A detailed structural analysis by using 1H–1H TOCSY NMR spectrum clarifies, for the first time, that chloropropyl trimethoxysilane (CPMS) forms covalent bonds with starch during starch modification and consequently forms covalent bonds with PLA in the step of blending to produce a reactive blend of PLA and CP-starch. The CP-starch covalently bound with PLA provides the compatibility between PLA and starch and also plays the role as nucleating agent as identified from a significant increase of degree of crystallinity (as high as 10–15 times), as well as induces chain mobility, as identified from a slight decrease in glass transition temperature (∼5–10°C). The PLA/CP-starch film performed as well as neat PLA with slight increases in tensile strength and elongation at break, as compared to other PLA/silane modified starch films.

Inhibition of brass corrosion in sodium chloride solutions by self-assembled silane films

Self-assembled monolayers (SAMs) of 3-mercaptopropyltrimethoxysilane (PropS-SH), dodecyltrimethoxysilane (DTMS), 3-aminopropyl(trimethoxy)silane (APS), and chloropropyl(trimethoxy)silane (CPTMS) were investigated to evaluate the influence of the silane molecule structure towards brass corrosion protection. The results indicated that SAMs of PropS-SH, CPTMS and DTMS inhibited the corrosion of brass in 0.2 M NaCl showing a mixed type behavior, while APS was not a good inhibitor. The inhibitive action of the PropS-SH and DTMS can be explained by chemisorption which obeys the Langmuir adsorption isotherm. The thiolate bond allows a better anchorage of the silane layer to the brass surface than the oxane bond.

Synthesis of Functionalized Iron Oxide Nanoparticle with Amino Pyridine Moiety and Studies on Their Catalytic Behavior

Aim: The main objective of this paper is to study the synthesis of functionalized iron oxide nanoparticle and its reactivity towards chromene synthesis Study design: Functionalized iron oxide nanoparticle study. Place and duration of study: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta, between December 2009 and July 2010. Methodology: This paper describes synthesis of stable functionalized iron oxide nanoparticles through surface modification of magnetic iron oxide nanoparticles by amino pyridine. Iron oxide nanoparticles were synthesized by co-precipitation method and the surface modification process was achieved by treating the nanoparticles with (chloro propyl trimethoxy silane) CPTS and aminopyridine. The developed functionalized iron oxide nanoparticle was evaluated as the catalyst for synthesis of chromones under MW irradiation conditions. Results: The catalysts were magnetically recovered and reusable without significant loss of their catalytic efficiency. To receive morphological and structural information on the obtained functionalized nanoparticle, the samples were analyzed by X-ray diffraction (XRD) measurements, FTIR and scanning electron microscopy (SEM) imaging. All synthesized chromene derivatives were characterized using analytical techniques such as IR, H NMR, and mass spectroscopy. Also the identity of these compounds was easily established by comparison of their melting point with those of reported samples. Conclusion: In summary, we have developed a new magnetically recyclable and Research Article American Chemical Science Journal, 1(3): 97-108, 2011 98 efficient functionalized magnetic nano catalyst for the chromene synthesis. Magnetic nanoparticle catalyst achieves a simple separation of catalyst without filtration including high yield in product.

High-κ Dielectric Sol−Gel Hybrid Materials Containing Barium Titanate Nanoparticles

Novel high-κ thin composite films with excellent breakdown strength were synthesized using nonhydrolytic sol−gel processing. Organic−inorganic hybrid materials with high electronic polarizability were prepared as the matrix material to form a covalently bonded interface with the organically modified barium titanate (TBT) nanoparticles through a chemical cross-linking reaction. To enhance the dispersion stability of barium titanate (BT) nanoparticles in the matrix, the chemical nature of their surfaces was modified using diethyl 3-(trimethoxysilyl)propyl phosphonate (TMSP), which was synthesized by the Michaelis−Arbuzov reaction of chloropropyltrimethoxysilane (CPTMS) with 3-triethyl phosphate (TEP). A high degree of dispersion of the dielectric BT nanoparticles significantly improved the dielectric properties of the final composite films. Because the matrix consists of both silane and halogenated bisphenol A moieties with high electronic polarizability, adjusting the chemical composition allowed tailoring...

Microwave-assisted One-pot Synthesis of Luminescent Organic–Inorganic Hybrids via Simultaneous Process of Sol–Gel and Suzuki–Miyaura Coupling Reactions

Abstract In order to disperse luminescent compounds with low solubility or high crystallinity into silica matrices, we demonstrate here facile one-pot synthesis of organic–inorganic luminescent hybrids via simultaneous process of sol–gel reaction of 3-(chloropropyl)trimethoxysilane (CPTMS) and the Suzuki–Miyaura homocoupling of 1-pyreneboronic acid under microwave irradiation. Highly luminescent hybrid without aggregates of the pyrene dimer, which was efficiently generated in situ, was obtained by microwave irradiation due to rapid formation of silica matrices, whereas huge aggregates were observed in the hybrid prepared under conventional heating.

Hydrothermal synthesis, physical characterization and photoluminescence of homologous-SBA-15 fabricated with Eu 3+

Two series of Eu 3+-doped homologous-SBA-15 materials (abbreviated as MPTMS-SBA-15: Eu 3+ and CTMS-SBA-15: Eu 3+) have been synthesized by a hydrolysis-controlled technology, in which two novel silane crosslinking reagents (3-(methacryloyloxy) propyltrimethoxysilane (MPTMS) and 3-(chloropropyl) trimethoxysilane (CTMS)) are used as silicate precursor instead of traditional tetraethoxysilane (TEOS). It can be found that the different silicate precursors with different functional groups have influence on the physical properties of the corresponding homologous materials. In comparison to the pure SBA-15, the BET surface area and pore size of the modified mesoporous materials have been changed. Finally, the characteristic luminescence is observed for the 5D 0 → 7F J ( J = 0, 1, 2) transition of Eu 3+ ion, suggesting that these kind of homologous-SBA-15 materials are potential host for the luminescence of Eu 3+, whose excitation energy can be quenched by Eu 3+ to some extent.

Effect of oxide thickness on the degradation of organic silane monolayers on silicon wafer surface during XPS measurement

AbstractMany organic materials are damaged and decompose by irradiation of X‐rays during XPS measurements. Factors for the decomposition and/or degradation are considered to be X‐ray, radiant heat and electrons from the X‐ray source, photoelectrons and the inelastically scattered electrons from the sample itself, and so on. We have established the method to evaluate the effect of electrons from the sample by using various inorganic materials as substrates. In this paper, the effect of the thickness of surface oxide layer of silicon wafer on the scission of CCl and CBr bonds in the organic silane monolayers on the wafer surface prepared from chloropropyltrimethoxysilane (CTMS) and bromopropyltrimethoxysilane (BTMS) modifiers has been investigated experimentally. The X‐ray source was monochromatic Al Kα, which eliminates the effect of heat and the electrons from the X‐ray source. Damaging factors evaluated from the decrease of peak intensity and the fitting to the 1st order reaction rate increased with the thickness of the oxide layer and saturated at about 7 nm. Consequently, the electrons from the sample are considered to be one of the main factors for sample degradation. Copyright © 2006 John Wiley & Sons, Ltd.

Photoreduction of Europium (III) in Sol-Gel Derived Inorganic-Organic Hybrid Materials

Eu2+-doped inorganic-organic hybrid materials, which are potentially suitable for a tunable laser in the near ultra violet and blue region, were prepared through the photoreduction of Eu3+ ions in the materials under the irradiation of the fourth harmonic wave light (266 nm) of the Nd:YAG laser. The hybrid materials doped with Eu3+ ions were prepared from Si(OCH3)4, CH3Si(OCH3)3, EuCl3 and chloropropyltrimethoxysilane (CPTM). After the prehydrolized silica sol was added to the Eu3+-containing solution, Eu3+-doped transparent inorganic-organic hybrid material was obtained by drying at 50°C. The emission peak around 450–475 nm due to the charge transfer transition (5d-4f) of Eu2+ ions increased with the laser irradiation time. Eu3+ ions were effectively photoreduced to Eu2+ ions in pore-free materials prepared at high CPTM to Eu3+ ratios. Eu2+ ions were generated by the photodecomposition of the bond between Eu3+ and Cl (Cl− or Cl(CH2)3 in CPTM).

THE EFFECTS OF SELECTED SOLVENTS ON ALLYLTRIMETHOXYSILANE AND CHLOROPROP YLTRIMETHOXYSILANE AND THE ROLE OF THESE SOLVENTS IN DETERMINING MUTAGENIC POTENTIAL IN SALMONELLA AND ESCHERICHIA COLI

Recently acquired bacterial mutagenicity test data (salmonella/Escherichia coli) indicated that allyltrimethoxysilane (ATMOS) showed mutagenic activity when prepared as a solution in ethanol but was not mutagenic in the same test when prepared in dimethylsulfoxide (DMSO), methanol, or acetone. Chloropropyltrimethoxysilane (CPTMOS)was positivein this assay whether ethanol, methanol, acetone, or DMSO was used as the solvent. A study was carried out to evaluate the effect of the solvent on each methoxysilane as it is prepared for the mutagenicity test. A scheme was used for ATMOS and CPTMOS in which 6 samples were prepared as 10 wt% solutions of either silane in ethanol, DMSO, or acetone(solvents commonly used in the bacterial mutagenicity test)and then analyzed by 29 Si NMR. The samples were then mixed 50:50 with pH 7 phosphatebuffered water and analyzed again over several hours. The solvent interaction with methanol was not investigated but is believed to be unlikely since the only reaction expected would be exchange of methoxy groups between the silane and methanol. These experiments showed that CPTMOS and ATMOS are stable in ethanol, acetone, and DMSO prior to dilution with water. Subsequently, aqueous dilutions of ethanol and acetone solutions of the two silanes did not undergo observable hydrolysis under these conditions. However, both methoxysilanes began hydrolysis immediately when the DMSO solutions were diluted with water. Condensation products were subsequently observed within 40 min. These data together with the differing bacterial mutagenicity test results for ATMOS in ethanol vs. methanol or acetone suggest that (1) the use of DMSO as a solvent for the mutagenicity testing of some methoxysilanes may be inappropriate and (2) alkoxysilanes in general should be tested in the compatible alcohols or other suitable solvent to avoid possible transalkoxylation reactions.

Determination of the acid-base properties for 3-amino, 3-chloro and 3-mercaptopropyltrimethoxysilane coatings on silica surfaces by XPS

The acid-base properties of three silanes, aminopropyltrimethoxysilane (APS), chloropropyltrimethoxysilane (CPS) and mercaptopropyltrimethoxysilane (MPS), as films deposited onto silica plates are compared by the measurement of elemental binding energy (BE) values using X-ray photoelectron spectroscopy (XPS). It is found that nitrogen from APS, chlorine from CPS and sulphur from MPS all interact with the silica surface as a base. From a comparison of oxygen O 1s and silicon Si 2p BE values for the three silanes with those of pure silica, mechanisms to describe the modes of attachment of the silane heteroatoms to the silica surface have been proposed. The influence of X-ray beam damage on atomic concentrations or BE values is found to be significant in all cases. Tests simulating outdoor weathering to determine changes in the silane film acid-base character from BE shifts are briefly discussed.