Trimethoxy Silyl Research Articles

Early detection of the ovarian cancer with a label-free and disposable ITO-PET based immunosensor platform

Alpha fetoprotein (AFP), a popular biomarker for ovarian cancer, was the target of this studyto create an immunosensor based on electrochemical impedance spectroscopy (EIS). For this purpose, a disposable Indium tin oxide coated PET (In2O3/SnO2, ITO-PET) electrode was used as a basic electrode for working of the triple electrode system and the electrodes were modified with 3-(Trimethoxy silyl) propyl methacrylate (3- TMSPM) silanization agent. Although there are studies on the determination of AFP, the determination of AFP with a cheap, flexible and sensitive electrode system such as ITO-PET in this study makes the study remarkable. With the designed biosensors, AFP protein determination at a wide concentration range (0.05 pg/mL-100 pg/mL) could be successfully performed. To prove that the designed immunosensor was constructed correctly, linear range, repeatability, reproducibility and regeneration capacity (characterization studies) were investigated. Obtaining successful results in the storage capacity studies of the biosensor, which has high reproducibility and repeatability, showed that it also has potential for commercial use. The high specificity of the biosensor also proves its reliability. Finally, the performance of the biosensor in commercial human serum samples was also evaluated.

Modification of Hydrotalcite Loading Tannic Acid with Organic Silane and Application in Anticorrosive Epoxy Coating.

Metal corrosion is a challenge for the world with heavy impacts on the economy. Study on the development of effectiveness anticorrosion additives is a promising strategery for the protection industry. This research focuses on the modification of hydrotalcite Mg-Al (HT) loading tannic acid (TA) with 3-(trimethoxy silyl) propyl methacrylate organo-silane (TMSPM) for applicating as an anti-corrosion additive for epoxy coating on the steel substrate. The suitable ratio of HT and modifiers was investigated and the suitable content of modified HT in epoxy matrix was found based on mechanical properties of the epoxy-based coating. The characteristics of modified HT were assessed through infrared (IR) spectroscopy, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), thermal gravimetry analysis (TGA), water contact angle (WCA), dynamic light scattering (DLS). Detailly, HT-TA3-S3 shows good stability in distilled water when HT/TA was modified with TMSPM which makes Zeta potential decreases significantly. Besides, SEM analysis presented HT-TA-S has a cylindrical shape about of 500 nm. Moreover, the crystallite size of HT/TA after being modified by TMSPM decreases sharply. All of these prove successfully synthesize HT loading TA with modified TMSPM. Water contact angle (WCA) decreases in case of loading TA and increases in case of modifying with TMSPM (WCA changed from HT (116.3°) to HT-TA (102.4°) and HT-TA-S (120.1°) which indicates the increased hydrophobicity of the sample. The obtained results showed HT/TA was modified successfully with TMSPM. The modification affected the size distribution and surface properties of HT nanoparticles while it did not impact on the crystal structure of HT. After incorporating modified HT/TA into the epoxy coating, the adhesion of coating to steel substrate was improved significantly. Consequently, the adhesion of epoxy/3 wt. % modified HT/TA coating was increased 3 times as compared to epoxy neat (from 0.76 MPa to 2.77 MPa). In addition, the relative hardness and gloss retention of epoxy/3 wt. % modified HT/TA coating reached the maximum values as compared to the others. Owing to salt spraying results, the epoxy/3 wt. % modified HT/TA exhibited an excellent anticorrosion ability for the steel substrate. All the above results show the potential of HT nanoparticles loading TA modified with TMSPM as anticorrosive additives for protective coatings on steel substrates.

Trimethoxy Silyl End-Capped Hyperbranched Polyglycidol/Polycaprolactone Particle Gels for Cell Delivery and Tissue Repair: Mechanical Properties, Biocompatibility, and Biodegradability Studies

This study focuses on the development of new biocompatible and biodegradable particle gel scaffolds based on PCL-HBPG/1SiHBPG triblock copolymers composed of a polycaprolactone (PCL) core and two outer blocks of trimethoxysilyl end-capped hyperbranched polyglycidol (HBPG/1SiHBPG) that have the potential to be used in soft tissue regeneration. The relationship between the gel’s composition, structure, mechanical properties, and performance has been investigated for the first time and the copolymer design parameters have been optimized. The particle gel scaffolds were formed from the concentrated dispersions of the most hydrophobic PCL-45HBPG/1SiHBPG at low temperatures, and were the result of the numerous hydrogen bonds formed from the HBPG/1SiHBPG moieties as well as the formation of siloxane crosslinks (i.e., Si–O–Si bonds). These gels were formed in the physiological temperature range. Gels with a mechanical strength that gradually increases were formed from the physically crosslinked PCL-45HBPG/1SiHBPG particles effectively and safely, in the absence of UV radiation. They feature high elasticity and undergo enzyme-triggered disassembly. The gels are biocompatible and have the potential to invoke cell attachment and differentiation in the absence of exogenous biological stimuli. A successful outcome of this study will be the prospect of a new approach for tissue regeneration that is currently not available.

Synthesis of Three Novel Silane-Based Carboxylic Acids for Application in Methacrylated Epoxy-Based Oligomers and Their Ability to Improve the Properties of UV Curable Hybrid Coatings

Improvement of thermal stability of silicone-based coatings was the main objective of this study. In this study bromoacetic acid (BAA) was reacted with 3-(mercaptopropyl) trimethoxy silane (MPTS) and trimethoxy silyl propyl thioacetic acid (TSTA) was produced. Also, bromoacetic acid (BAA) was reacted with 3-(triethoxysilyl) propylamine (APTS) and triethoxysilyl propylamino acetic acid (TSPA) was synthesized. Finally, from a reaction between trimellitic anhydride (TMA) and APTS, trimellitylimidopropyl triethoxysilane (TMIS) resulted. Compounds containing carboxylic acids and trimethyl silane were obtained in all of these reactions. Furthermore, hybrid coatings based on methacrylated bisphenol A epoxy (MBAE) and the synthesized carboxylic acids were obtained by photopolymerization. Polycarbonate substrates were utilized for preparation of the transparent hybrid films. Then the solvent resistance, hardness and gel content, as well as the adhesion of the coatings, were measured as physical and mechanical properties. According to the obtained results, these properties of the hybrid coatings were improved with the increase in alkoxysilanes and sol–gel precursor contents. The surface morphology was characterized by scanning electron microscopy (SEM). The results showed that silica particles were not dispersed homogenously at the molecular level in the hybrid system. Also, the thermogravimetric analysis results indicated that alkoxysilanes enhanced the thermal oxidative stability of the hybrid coatings.

Titanium particles incorporated polymer monolith microcolumn for phosphoprotein enrichment from biological samples

In proteomic studies, selective enrichment of target phosphoproteins from biological samples is of importance. Of various enrichment methods, affinity chromatography is widely preferred method. Development of micro-affinity columns with simple strategies are in constant demand. Here in this report, for the first time, we have embedded TiO2 particles within the monolith structure in a single step. Fourier transform infrared spectroscopy and scanning electron microscope analysis has confirmed the successful incorporation of TiO2 particles within the polymer monolith. Incorporation of 3-(trimethoxy silyl) propyl methacrylate within the poly(hydroxyethyl methacrylate) based monolith composition has enhanced its rigidity and one fold phosphoprotein (α-casein) adsorption capacity. Presence of only 66.6 µg of TiO2 particles within the monolith has displayed a four-fold higher affinity to α-casein over the non-phosphoprotein i.e. bovine serum albumin. Under optimized conditions (TiO2 particle and acrylate silane), the affinity monolith has a maximum adsorption capacity of ∼ 72 mg per gram monolith. Translation of TiO2 particles-monolith into a microcolumn of 3 cm long and 19 µL volume was successful. α-casein was selectively separated from an artificial protein mixture of α-casein and BSA, α-casein spiked human plasma, and cow milk within 7 min

Surface modification of zirconia by various modifiers to investigate its reinforcing efficiency toward nitrile rubber

AbstractUniform dispersion of metal oxide‐like zirconia in elastomeric matrix is an essential requisite to deliver proper reinforcement. However, inadequate compatibility between the hydrophobic elastomer and the hydrophilic zirconia surface makes this a difficult task. In this work, three different surface modifiers, namely, sodium dodecyl sulfate (SDS: a surfactant), 3‐(trimethoxy silyl) propyl methacrylates (MPS: an organosilane), and tris (hydroxymethyl) aminomethane (Tris: an amine buffer) are employed to modify the surface of sol–gel derived in‐situ generated zirconia. Effect of surface modification of zirconia by these different kinds of surface modifiers on zirconia‐filled nitrile rubber (NBR) composite has been critically investigated in terms of thermal, morphological, mechanical, swelling, rheological, and dielectric properties. Temperature of maximum degradation (Tmax) of the NBR gum (439 °C) is improved upon incorporation of all type of modified zirconia while that is maximum for Tris‐modified zirconia‐filled composite (458 °C). Similar trend is observed in stress–strain study where Tensile strength is enhanced up to six times for the filled composites relative to NBR gum (1.03 MPa) and the highest value is shown by Tris‐modified zirconia‐filled composite (6.35). This study reveals that Tris could be a potential surface modifier for metal oxides like zirconia, as an alternate to organosilane, to reinforce the elastomer matrices.

Hybrid nanoparticles based on novel Schiff Base for durable flame retardant and antibacterial properties

A large amount of cellulose is produced by photosynthesis every year, and cellulose products are widely used in daily life. However, flammability and easy to breed bacteria of cellulose has hidden risk of fire and public health during using, and the materials that can endow cellulose with flame retardancy and antibacterial properties is still lacking. Herein, novel hybrid nanoparticle (SiDP) based on inorganic nano SiO 2 , Schiff base and quaternary ammonium salt was developed to synchronize these two properties. Wherein the thermal stability of nano SiO 2 and the cross-linking structure of Schiff base played as synergistic flame retardant for the nanoparticle while quaternary ammonium salt of N, N′-dimethyl-N-(3-(trimethoxy silyl) propyl) octadecan-1-aminium chloride (DMOAC) was introduced to provide antibacterial property. The results demonstrated that the modified cotton fabrics were significantly out-performing of flame retardancy and antibacterial properties. Wherein LOI increased to 27.6%, the peak of heat release rate (pHRR) reduced by 34.2%, and capability of self-extinguishing was achieved. The antibacterial of SiDP and modified cotton fabrics were substantiated up to 99.9% against the Staphylococcus aureus and Escherichia coli. More excitingly, low toxicity of SiDP was confirmed via MTS assay by L929 fibroblast cells. The anti-infection in-vivo model was constructed and confirmed SiDP had a positive prevention of infection based on the wound healing rate of 91.1% after 14 days' treatment. The flame retardancy, antibacterial and biocompatibility of SiDP indicated it was an ideal candidate of nanomaterials in cellulose modification.

Novel Multifunctional Spherosilicate-Based Coupling Agents for Improved Bond Strength and Quality in Restorative Dentistry.

The aim of this study was to investigate the restorative connections of composite materials after fracture, under controlled conditions of treating the materials with novel, spherosilicate-based (SS) primers bearing both methacryl (MA) and trimethoxysilyl (TMOS) groups. The chemistry of methacrylate group insertion and reactive groups hydrolysis has been studied with the aid of 1H NMR (Nuclear Magnetic Resonance) spectroscopy. The light-cured resin composites were repaired by activating the connection site with the obtained primers and, for comparison, a silane (methacryloxypropyltrimethoxysilane, MATMOS) as a conventional coupling agent bearing the same reactive groups. The resistance of such a joint was tested in a three-point bending test after 24 h and 28 days period of sample conditioning. The effect of bond application was also studied, showing that spherosilicate-based primers may be used more effectively than MATMOS for two-step (primer-composite) restorative process, while for silane, the three-step process with bond application is crucial for satisfactory joint quality. The joint failure mode was determined by microscopic analysis and it was found that SS-4MA-4TMOS and SS-2MA-6TMOS application resulted in mostly composite, and not joint, failure. After 28 days of conditioning, the flexural strength of the joint repaired with SS-4MA-4TMOS was at 94% of the neat, solid material under the same procedure. However, the strength of the neat composite was observed to decline during the conditioning process by ~30%. The joint behavior was explained on the basis of the gradual hydrolysis effect (the greatest decrease being observed for silane).

Preparation of antimicrobial PVDF and EVOH membranes by grafting quaternary ammonium compounds

Dimethyl octadecyl [3-(trimethoxy silyl) propyl] ammonium chloride (DMOAP) was grafted on polyvinylidene fluoride (PVDF) membranes and ethylene-vinyl alcohol copolymer (EVOH) membranes, and the effects of preparation conditions on the grafting rate and antimicrobial performance of the membranes were investigated. The result showed that the grafting rate of membranes increased with the increased DMOAP concentration. The ion exchange capacity rose first and then declined with the increase of reaction temperature and time. The membranes displayed excellent antimicrobial performance against Escherichia Coli. The EVOH membranes also showed good stability, remaining 86% of the initial ion exchange capacity after the cyclic soaking test (312 h).

Efficient Removal of Pb(II) from Aqueous Medium Using Chemically Modified Silica Monolith.

The adsorptive removal of lead (II) from aqueous medium was carried out by chemically modified silica monolith particles. Porous silica monolith particles were prepared by the sol-gel method and their surface modification was carried out using trimethoxy silyl propyl urea (TSPU) to prepare inorganic–organic hybrid adsorbent. The resultant adsorbent was evaluated for the removal of lead (Pb) from aqueous medium. The effect of pH, adsorbent dose, metal ion concentration and adsorption time was determined. It was found that the optimum conditions for adsorption of lead (Pb) were pH 5, adsorbent dose of 0.4 g/L, Pb(II) ions concentration of 500 mg/L and adsorption time of 1 h. The adsorbent chemically modified SM was characterized by scanning electron microscopy (SEM), BET/BJH and thermo gravimetric analysis (TGA). The percent adsorption of Pb(II) onto chemically modified silica monolith particles was 98%. An isotherm study showed that the adsorption data of Pb(II) onto chemically modified SM was fully fitted with the Freundlich and Langmuir isotherm models. It was found from kinetic study that the adsorption of Pb(II) followed a pseudo second-order model. Moreover, thermodynamic study suggests that the adsorption of Pb(II) is spontaneous and exothermic. The adsorption capacity of chemically modified SM for Pb(II) ions was 792 mg/g which is quite high as compared to the traditional adsorbents. The adsorbent chemically modified SM was regenerated, used again three times for the adsorption of Pb(II) ions and it was found that the adsorption capacity of the regenerated adsorbent was only dropped by 7%. Due to high adsorption capacity chemically modified silica monolith particles could be used as an effective adsorbent for the removal of heavy metals from wastewater.

Synthesis and characterization of ladder structured ormocer resin of siloxane backbone and methacrylate side chain

Available resin-based hard tissue restorations are highly influenced by the problems associated with post-polymerization shrinkage and toxicity of uncured monomers. To address this scenario, we have synthesized an ormocer resin (LSM) of inorganic siloxane backbone using the monomer 3-(trimethoxy silyl)propyl methacrylate (3-TMSPM) by modified sol gel method. The synthesized polycondensed LSM resin is fashioned with three-dimensional network of ladder structured Si-O-Si backbone which grow continuously to form higher molecular weight (Mn-18956 KDa) prepolymer. Four membered siloxane rings along with intact methacrylates constituted the monomeric unit of the prepolymer LSM. High thermal stability indicated the presence of intense siloxane network whereas low glass transition temperature and melting peak demonstrated the flexibility and partial crystallinity of the LSM resin. Low linear polymerization shrinkage (LPS) of cured LSM resin (0.422 ± 0.04%) witnessed the presence of inorganic siloxane backbone and performed better than cured bisphenol glycidyl methacrylate (BisGMA)composite (0.916 ± 0.09%). Non-cytotoxicity and cytocompatibility of the cured LSM resin proved the eligibility of the resin for hard tissue restorative applications.

Synthesis, structural characterization, electrochemical and photocatalytic properties of vanadium complex anchored on reduced graphene oxide

In this work, vanadium complex anchored reduced graphene oxide (rGO-VO) was successfully synthesized by coordination interaction with phenyl azo salicylaldehyde (PAS) coupled trimethoxy silyl propanamine (TMSPA). The physicochemical and microscopic properties of rGO-VO were studied with different analytical techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) which confirmed the synthesis of rGO-VO. The electrochemical studies of rGO-VO in glassy carbon electrode demonstrated high current density because of the amazing electrochemical properties of rGO. The photocatalytic studies of anchored rGO-VO and VO(acac)2 toward MB dye indicated that anchored rGO-VO with visible light irradiated MB was degraded fast as compared to VO(acac)2.

Silane treatment of drop-on glass-beads and their performance in two-component traffic paints

In this research, the surface of drop-on glass beads (GBs) was first etched, then modified using 3- trimethoxy silyl propyl methacrylate (MS) and trimethoxy vinyl silane (VS) through a sol-gel process to improve GBs’ adhesion to the two-component methyl methacrylate-based traffic paints (known as cold plastic paints). The etching was conducted in acidic, neutral, and basic conditions. Acidic etching condition was selected for the further experiments considering the highest number of OH groups provided by etching reaction on the surface of GBs. The FTIR and 13C-NMR spectroscopy were utilized to characterize chemical composition, and Atomic Force Microscopy (AFM) was used to evaluate the surface roughness / topography of the pretreated and silane-treated GBs. The amount of silane coated on the surface of the GBs was determined using thermogravimetric analysis (TGA). The dispersion of silane compounds on the surface of the treated GBs was assessed using Energy Dispersive X-Ray Analysis (EDXA). Neat and silane-treated GBs were then sprayed on freshly applied cold plastic paint samples using a designed lab spray device. Optical microscopy was used to evaluate the proper embedment depth of the GBs onto the surface of the paint samples. The abrasion test was performed in dry and wet conditions to evaluate the adhesion strength of neat and silane-treated GBs to the paint surface in normal and rainy weather. The coefficient of retroreflected luminance (RL) and the luminance coefficient under diffuse illumination (Qd) were measured to characterize the night and day retroreflective performance of cold plastic paints containing treated and untreated GBs. The abrasion test results showed the least weight loss in the paint markings containing drop-on VS-treated GBs (VS.GBs) in comparison to neat and MS-treated GBs (MS.GBs). This was assigned to increase in adhesion strength and interfacial interactions between VS.GBs and the polymeric matrix. The measured values of RL and Qd also confirmed the excellent maintenance of drop on VS.GBs on the surface of the two-component traffic paints.

One‐Step Synthesis of Alkaline‐Soluble Polystyrene Containing Trimethoxysilyl‐ and Boronic Acid‐Moieties as Inorganic, Reactive Pendant Groups for Photosensitive Materials

AbstractIt is of great interest in simple preparation of organic–inorganic hybrid thermoset soluble in alkaline developer, intended for photosensitive materials used in the field of semiconductor packaging based on sophisticated molecular design from the viewpoint of performance improvement and cost reduction. Here successful one‐step synthesis of alkaline‐soluble polystyrene with three kinds of pendant groups along the chain; trimethoxysilyl (TMS), boronic acid (BA), and hexafluoroisopropylalcohol (HFA) groups is shown. Solvent composition‐based equilibrium control of reactions involving the inorganic pendant groups (TMS and BA) as well as the hydrogen bonding ability and sterically bulky structure of the HFA group are effective in suppressing cross‐linking reactions during polymerization. The latter is confirmed through DFT calculation and terpolymerization experiments where the effect of the HFA group is compared to other ten kinds of p‐substituted functional groups. The obtained terpolymer is soluble in alkaline developer and forms an insoluble membrane with high heat‐resistance after heat treatment. Furthermore, its photosensitive polymer composition with photochemical acid generator exhibits negative‐type photosensitivity. The organic–inorganic hybrid thermosetting polystyrene is a promising material for semiconductor package applications.

Effect of silylating agents on the superhydrophobic and self-cleaning properties of siloxane/polydimethylsiloxane nanocomposite coatings on cellulosic fabric filters for oil-water separation.

A new facile approach for preparing two nonfluorinated hybrid organic–inorganic siloxane/polydimethylsiloxane nanocomposite coatings for cotton fabrics is presented using two distinct silylating agents. The first coated fabric was prepared predominantly via trimethylsilyl modification using hexamethyldisilazane (HMDS) while higher amounts of trimethoxy(octadecyl)silane (TMOS) further enhanced the superhydrophobicity of the second coating matrix. Unlike HMDS with substituted silyl (Me3Si) groups, TMOS consists of hydrolysable trimethoxy silyl ((MeO)3Si) chemical groups that allowed for the formation of nanosilica with Si–O–Si linkages needed to foster stable coatings. After characterization and testing, these coated fabrics demonstrated varying responses to harsh solvents and thermal conditions. Both sets of coated fabrics exhibited unique capacities for self-cleaning and oil–water separation as superhydrophobic filters due to (a) their low surface energy silylated hybrid polysiloxane chemical groups, (b) their highly reduced surface wettability and (c) nanopatterned surface morphologies. In this study, coated superhydrophobic cotton fabrics revealed a higher static aqueous contact angle of more than 150° and sliding hysteresis angle of less than 5°. Coated fabrics with 30 mg TMOS/10 mg HMDS (CMF3) and 30 mg HMDS/10 mg TMOS (CTF3) exhibited optimal superhydrophobicity. Both fabrics also retained percentage separation efficiencies over 90% for both chloroform–water and toluene–water mixtures. However, CTF3 displayed with a recorded separation efficiency less than 90° after five filtration cycles.

Preparation, evaluation and functionalization of biomimetic block copolymer coatings for potential applications in cardiovascular implants

Effective prevention of the formation of blood coagulation is crucial in blood contact devices. Moreover, the specific service environment also requires specialized function. In this study, triblock copolymers containing zwitterionic units of phosphorylcholine (PC) and nonionic units of trimethoxysilyl (TMS) were synthesized via atom transfer radical polymerization (ATRP). In addition, random copolymers containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) were synthesized via conventional free radical polymerization. Further, the polymers were immobilized on biomedical metal sheets to construct biomimetic antifouling coatings via covalent fixation. Experiments, including contact angle (WCA) measurements, platelet adhesion, and fibrinogen denaturation, show that one of the triblock copolymers, MePBMTM III sample, exhibited the best hemocompatibility and labeled as MePBMTM in the follow-up evaluations. Finally, vascular endothelial growth factor (VEGF) was introduced on the MePBMTM coating via covalent fixation. The results of X-ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM) confirmed the successful fabrication of VEGF/triblock phospholipid polymers coating. In vitro smooth muscle cells (SMCs) cultures revealed that the VEGF/triblock phospholipid polymers coating significantly inhibited the attachment and proliferation of SMCs. In vitro endothelial cells (ECs) and endothelial progenitor cells (EPCs) cultures further confirmed that the VEGF/triblock phospholipid polymers coating effectively promoted their adhesion and proliferation.

Pd nanoparticle incorporated mesoporous silicas with excellent catalytic activity and dual responsivity

Functionalised mesoporous silica SBA-15 was designed to exhibit dual responsive behaviour by grafting poly [2- (N, N-dimethylamino) ethyl methacrylate] (PDMAEMA) via free radical polymerisation. For this, the SBA-15 was modified by 3-(trimethoxy silyl) propyl methacrylate (TMSPM) for allowing methacrylate functionality on the mesoporous surface for free radicle polymerisation (m-SBA-15). Temperature and pH responsive PDMAEMA were grafted on the well-ordered rod-like m-SBA-15. Monometallic palladium (Pd) nanoparticles (NPs) were then incorporated in the pre-synthesised m-SBA-15/PDMAEMA. The morphology and structure of resulting materials were characterised by powder X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, field emission scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption-desorption isotherms. The dual stimuli-responsive behaviour of the hybrid material was monitored by dynamic light scattering measurement. Synthesised materials were tested for their dual stimuli (pH and temperature)-responsive catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). It was observed that the catalytic activity of the Pd/m-SBA-15/PDMAEMA catalyst was significantly higher at a given pH and temperature than any of SBA-15 only without using PDMAEMA and Pd NPs, m-SBA-15 grafted with PDMAEMA without Pd NPs, or Pd NPs incorporated m-SBA-15 without grafting PDMAEMA.

Photophysical and Electrochemical Studies of Anchored Chromium (III) Complex on Reduced Graphene Oxide via Diazonium Chemistry

Covalently anchored chromium complex on reduced graphene oxide (rGO‐Cr) is successfully synthesised through trimethoxy silyl propanamine (TMSPA) and phenyl azo salicylaldehyde (PAS) coupling. The rGO‐Cr is characterised by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), electron dispersive analysis of X‐rays (EDAX), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Absorption and emission properties of rGO‐TMSPA‐PAS are studied by excitation dependent photoluminescence emissions at room temperature. Electrochemical sensing activity of rGO‐Cr is monitored for paracetamol using modified glassy carbon electrode. Cyclic voltammetry measurements indicated that rGO‐Cr substantially enhance the eletrochemical response of paracetamol. The experimental factors are investigated and optimized.

Multi-functional urethane epoxy acrylates (UEAs) and their visible-light cured UEA/MSMA-colloid silica nanocomposite films as reinforcement on polycarbonate matrix

The multi-functional methacrylates are prepared through polycondensation by isophorone diisocynante (IPDI), pentaerythritol triacrylate (PETA) reacting with epoxy acrylate, 2,2-bis[4-(20-hydroxy-30-methacryloyloxypropoxy)phenyl]propane (Bis-GMA), the series of urethane epoxy acrylate resins are successfully synthesized. The urethane epoxy acrylate oligomer’s structure is characterized by Fourier transform infrared spectroscopy (FT-IR). In order to enhance the hardness of the resins, the colloidal silica is successfully reacted with 3-(trimethoxy silyl)propyl methacrylate (MSMA). The characteristics of the colloidal silica/MSMA are measured by means of dynamic light scattering (DLS). The acrylate functional groups are chemically bonded to the surface of the silica spheres, enhancing the compatibility of the organic/inorganic interface; the highest hardness can reach 7H, and the adhesion of the PC reaches 5B. The thermal properties of the cured coating are investigated by means of thermal gravimetric analysis (TGA), with the decomposition temperature (Td) reaching up to 440°C.

Multifunctional Inorganic-organic Hybrid Resins With Polymerizable Methacrylate Groups For Biomedical Applications; Effects Of Synthesis Parameters On Polymerisation Shrinkage And Molecular Weight

Inorganic-organic hybrid resins revolutionarize the biomedical field by virtue of its versatility. In this work, bioactive inorganic-organic hybrid resins containing mixture of alkoxides of calcium/magnesium/zinc with polymerizable tetramethacrylate groups was synthesized using 1,3-bis methacryloxy 2-(trimethoxy silyl propoxy) propane as the precursor. We optimised the processing parameters by investigating the influence of pH of the medium used for the hydrolysis of silane on molecular weight of the resultant resin obtained. Physico-mechanical properties including polymerisation shrinkage of photocured composites prepared from novel inorganic-organic hybrid resins were evaluated and compared. The resin hydrolysed at pH 2 have low molecular weight with high filler loading capacity (325 phr) than the one hydrolysed at pH 10. Photocured polymeric composite fabricated from resin hydrolysed at pH 2 showed lower polymerisation shrinkage, better depth of cure, good diametral tensile strength, non-cytoxic to L929 fibroblasts with good cell viability and cell adhesion. This new biocompatible polymer with low polymerisation shrinkage stands as a potent candidate in biomedical applications, especially in the field of dental, orthopaedic and coating applications. Copyright © 2016 VBRI Press.