Propyl Trimethoxy Silane Research Articles

Effect of superficially modified zinc oxide nanoparticles as an additive on the rheological performance of asphalt binder

The surface effect that hinders the dispersion of nanomaterials in the asphalt binder due to the large surface area and small particle size should be investigated. Thus, this study evaluates the effect of the incorporation of superficially modified zinc oxide nanoparticles (ZnO M) by 3-(2.3-epoxypropoxy)propyl trimethoxysilane (GPTMS) in the asphalt binder with 50/70 penetration index. The additive was incorporated in contents of 3%, 5%, and 7% in weight of the bind through physical and rheological tests. Penetration tests, softening point, rotational viscosity, performance grade (PG) – before and after rolling thin film oven (RTFO), multiple stress creep and recovery (MSCR), linear amplitude sweep (LAS), and master curve were performed. The addition of ZnO M nanoparticles provided the asphalt binder with more resistance to aging and oxidation in almost all properties analysed. In addition, the ZnO M increased resistance to permanent deformation, temperature field, and the integrity of the asphalt binder, thus increasing its fatigue life.

Silane modification of nanofibrillated cellulose and its effect on the properties of waterborne acrylic resin

AbstractNanofibrillated celluloses (NFC) have attracted tremendous attention as nanofillers to improve the mechanical properties of waterborne resin. In this study, NFC was prepared by mechanical fibrillation, and then modified respectively with three different types of silane coupling agents: γ‐aminopropyltriethoxysilane (KH550), γ‐(2, 3‐epoxypropoxy) propyl trimethoxysilane (KH560), and γ‐(methacryloyloxy) propyl trimethoxysilane (KH570). The obtained NFC and modified NFCs were physically mixed with water‐based acrylic resin (WAR) to prepare films by casting method. The NFC, silanized NFC, and films were analyzed by Malvern laser particle sizer, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric analyzer (TGA), water contact angle (WCA), rotational rheometer, and power stretchers, respectively. Results showed that NFCs were successfully prepared and modified. The KH570 modified NFC had a slightly smaller particle size, higher absolute Zeta potential and yield stress values, good thermal stability, and exhibited better dispersion and suspension stability in solution. However, the NFC modified by KH560 had the best improvement effect on the mechanical properties and hydrophobicity of WAR membranes. Adding only 0.3 wt% KH560 modified NFC could increase the tensile strength of WAR film by 131.9%, and the WCA of the film could be increased from 85.2° to 101.6°, which makes this study beneficial for promoting the application of nanofibrillated cellulose in WAR.

Ni-rich cathode materials with enhanced kinetics and hydrophobicity endowed by reactive silane coating

Intimate conformal coating with well-controlled thickness and rational-designed composition could work as an artificial cathode electrolyte interphase (CEI) to greatly enhance the cycle stability, moisture tolerance and even kinetics performance of Ni-rich layered oxides (NROs). While complicated treatment is usually required in coating thickness control. Inspired by the amphipathicity and monolayer self-assembling properties of silane coupling agent, herein two kinds of silanes with short hydrophobic functional group, allyltrimethoxysilane (ALTS) and propyltrimethoxysilane (PRTS), are adopted in NRO modification. We find that the silanes could form a conformal coating with self-limited thickness controlled by its reaction with the inevitable –OH or lithium residues on NRO surface. The optimal material, CGAP, not only shows enhanced cycle stability and rate performance, but also impressive moisture tolerance. It retains 93.9% of its capacity in 200 cycles at 25°C, and a high reversible capacity of 192.8 mAh g−1 even after 7 days of exposure in the environment with 60% humidity.

Amine-functionalized metal-organic framework/graphene oxide nanocomposite for the removal of Direct Red 23 from water

Herein, MIL-53 (Fe) and MIL-53 (Fe)/graphene oxide (GO) nanocomposite were synthesized and denoted as MIL-C, and MIL-C/GO. The synthesized materials were modified using 3-amino propyl trimethoxy silane (APTMS) (amine-functionalization) with different amounts (0.1, 0.2, and 0.3 mL for preparing MIL-C/NH2(0.1), MIL-C/NH2(0.2), and MIL-C/NH2(0.3), MIL-C/GO-NH2(0.1), MIL-C/GO-NH2(0.2), and MIL C/GO-NH2(0.3), respectively) and characterized. Direct Red 23 (DR23) was used as a model pollutant. The dye adsorption followed a Langmuir isotherm and pseudo-second-order model. The MIL-C/GO and MIL-C/GO-NH2(0.3) showed the adsorption capacity of 1,371 and 4,504 mg/g, respectively. The high removal ability and reusability indicated that the synthesized MIL-C/GO-NH2(0.3) could be as an alternative adsorbent for other organic contaminant with similar chemical structures from aqueous media.

Electrospun nanoscale bent fibrous membrane with controllable porous structure and hydrophilic modification for high-efficiency oil-water separation, particle/bacterial filtration and antibacterial applications

Electrospun nanofiber membranes' pore structure and hydrophilicity are essential for water filtration. Pore size may be efficiently lowered in this work by decreasing the fiber diameter, changing the fiber morphology, and constructing a silicon hybrid hydrophilic coating. The hydrophilic nanofiber membranes have a small pore size (0.72 μm) and an extremely low diameter (73.5 nm). Meanwhile, the synergistic combination of catechol (CA) and tannic acid (TA) with γ-(2, 3-epoxypropyl) propyl trimethoxysilane (KH560) resulted in the formation of a homogenous silicon hybrid hydrophilic coating on the surface of the fiber membrane. The hydrophilic nanofiber membrane has an outstanding hydrophilicity (WCA = 28.3°), excellent oil-in-water emulsion separation efficiency (>99.0%), extremely high particle filtration efficiency (>99.0%), and an LRV value of more than 7.50 for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). At 6.0 mg/mL, the antibacterial efficiency was 80% against E. coli and 96% against S. aureus. The preparation of such hydrophilic membranes can provide a novel strategy for high-quality design and development that can be applied to various water filtration applications.

Fabrication and excellent performance of amorphous FeSiBCCr/organic-inorganic hybrid powder core

Soft magnetic composites (SMCs) are widely used in relevant inductance components in power and electronic fields. The development of high frequency devices requires SMCs to exhibit good insulation and excellent soft magnetic properties. The insulation coating for SMCs is crucial, and it is necessary to ensure that the coating thickness is uniform and maintains excellent adhesion to the powder. In the present work, a novel and efficient solution for the formation of insulating coatings, i.e. phytic acid/silane (denoted as PAS) organic-inorganic hybrid solution, was prepared by the condensation reaction between PA and γ-(2,3-epoxypropoxy) propyl trimethoxy silane. The FeSiBCCr@PAS powder with a core-shell structure has been successfully prepared through chemical reaction in a modified PAS solution. The effects of insulating coating content on the magnetic and mechanical properties of FeSiBCCr@PAS powder cores were systematically investigated. The PAS hybrid insulating coating can significantly improve the DC-bias performance and reduce the core loss. The optiomal powder core, which was prepared by using the powder coated with 3 g/L phytic acid, exhibits a minimum core loss (P50mT/1MHz) of 2979.2 mW/cm3, high effective permeability μe(0.1A/m) of 33.8, and superior DC-bias(100Oe) performance of 80.8%. Present work developed an effective method to prepare high performance powder cores with good soft magnetic and mechanical properties.

Surface chemistry regulation of nanoparticle coatings on activated carbons for rapid and long-lasting adsorption of organic pollutants

The nature of activated carbons (AC) to possess large specific surface areas and highly developed internal channels, is beneficial to absorb a variety of organic pollutants for practical applications in widespread areas, such as odor removal, flue gas cleaning and water purification. However, the domination of water affinity on AC could promote the adsorption to saturation in a short period, hindering the adsorptive performance on organics and reducing the service life severely. Thus, a simultaneous demonstration of the remarkable adsorptive property along with moisture resistance is of great significance. In this work, the superhydrophobic ACs with selective adsorptive property were fabricated via the combination of pretreatment to roughen the surface and grafting of propyl trimethoxysilane on superhydrophobic nanoparticles. The design was verified by the theoretical calculation of density functional theory accompanied with surface grafting ratio, and the as-prepared ACs presented favorable damp- and water-proof ability in the long term, showing only 11.8% weight increment for up to 180 days in high humidity. More importantly, superhydrophobic ACs exhibited effective capture of organics for continuous adsorption under aqueous phase and humid conditions, with removal efficiency over 90%.

Application of Alumina Nanofibers as Adsorbents for the Removal of Mercury (II) and Lead (II) from Aqueous Solutions

This study aims to design novel amine-functionalized alumina nanofibers for the removal of lead (II) and mercury (II) ions from aqueous solutions. The γ-Al2O3 nanofibers were prepared by calcination of boehmite, and then functionalization with 3-(2-aminoethylamino) propyl trimethoxy silane. The characterization of the nanofibers was carried out using TEM, EDS, elemental mapping, XRD, and XPS. The effects of initial concentration, pH, contact time, and selectivity were studied. The results revealed that the nanofibers can remove 98% of Hg2+ ions and 90% of Pb2+ ions from aqueous solution at concentrations of 40 mg/L and 35 mg/L, respectively. Additionally, the optimal pH conditions for mercury and lead ion adsorption were established to be 6. It was also observed that for concentrations of 100 mg/L and 250 mg/L, the majority of ion contaminants were removed by the nanofibers within the first hour. The adsorption capacities were found to be 129 mg/g and 165 mg/g for Hg2+ and 72.3 mg/g and 111 mg/g for Pb2+ at 100 mg/L and 250 mg/L concentrations, respectively. The ion-adsorption kinetic data was best fitted to a pseudo-second-order model. High sorption capacities were also demonstrated when employed to selectively adsorb mercury (II) and lead (II) ions from aqueous solutions containing Zn2+, Mg2+, Cu4+, Sn4+, and Ni4+. Desorption tests were performed to explore the stability of the heavy metals on the nanofiber.

Fabrication of magnetic magnesium oxide cleanup adsorbent for high-throughput pesticides residue analysis coupled with supercritical fluid chromatography-tandem mass spectrometry

A rapid and accurate analytical method was established for multiple pesticide residues in complex matrices based on magnetic dispersive solid phase extraction (d-SPE) and supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS). To develop an efficient magnetic d-SPE method, magnetic adsorbent modified with magnesium oxide (Fe3O4–MgO) was prepared via layer-by-layer modification and used as cleanup adsorbent for removal of interferences that contain a large number of hydroxyl or carboxyl groups in the complex matrix. The obtained Fe3O4–MgO coupled with 3-(N,N-Diethylamino)-propyltrimethoxysilane (PSA) and octadecyl (C18) were used as d-SPE purification adsorbents and their dosages were systematically optimized with Paeoniae radix alba as the matrix model. Combined with SFC-MS/MS, rapid and accurate determination of 126 pesticide residues in the complex matrix was achieved. Further systematic method validation showed good linearity, satisfactory recovery, and wide applicability. The average recoveries of the pesticides at 20, 50, 80, and 200 μg kg−1 were 110, 105, 108, and 109%, respectively. The proposed method was applied to complex medicinal and edible root plants, such as Puerariae lobate radix, Platycodonis radix, Polygonati odorati rhizoma, Glycyrrhizae radix, and Codonopsis radix. The average recoveries of the pesticides at 80 μg kg−1 in these matrices were 106, 106, 105, 103, and 105%, respectively with an average relative standard deviation range of 8.24–10.2%. The results demonstrated the feasibility and wide matrix applicability of the proposed method, which is promising for pesticide residue analysis in complex samples.

Development of biomaterial-based oxygen transportation vehicles for circulation within blood

BackgroundSeveral blood replacements have been developed because of issues with blood collection and storage, increased expenditures, and a global lack of reserves. Studies on artificial blood primarily concentrate on the research and synthesis of molecules that transport oxygen. The primary objective of the current work was to create a supporting, oxygen-carrying biological material that can replace blood and be used to save lives when blood is not available. MethodsThe work started with the synthesis of superparamagnetic iron oxide nanoparticles (SPIONS), and two distinct procedures were applied to ensure binding to hemoglobin (Hb) molecules. The surface modifications of the particles were carried out gradually by 3-amino propyl trimethoxy silane (3APGASPIONS) and tartaric acid (TASPIONS). Analysis methods used to characterize the particles include Fourier transform infrared spectrophotometer (FT-IR), elemental analysis (EDX), scanning electron microscope (SEM), X-ray diffractometry (XRD), and high contrast transmission electron microscopy (C-TEM). The characterization studies of SPIONS which bind Hb molecules to the surface were repeated and their effects on endothelial cell culture were examined to determine their toxic effects in vitro. Cell proliferation, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity changes were assessed in the evaluation of the possible toxic effects of the cells against the treated particles in the prepared cell lines. Blood substitute solutions synthesized by two different methods were stored on the shelf for about 1 month and the results were compared with fresh Hb solutions. Results and ConclusionThe CV and UV analysis results obtained from artificial Hb substitutes revealed that the structural integrity of Hb molecules did not change, the oxygen transport capabilities of biomolecules were preserved, and this state remained stable for a long time. Furthermore, it was determined that nanocomplexes synthesized by the two methods caused different cellular proliferation and there was a more limited increase in cellular enzyme activities (SOD, CAT, GPx) of Hb-bound particle solutions when compared to pure SPIONS.

QuEChERS-liquid chromatography-tandem mass spectrometry for determination of 22 triazole pesticide residues in Chinese herbal medicines

Eight well-known herbals in Zhejiang Province, Zhebawei, are commonly used as traditional Chinese herbal medicines owing to their rich active ingredients. However, the unavoidable use of pesticides during agricultural production has led to pesticide residue problems in these herbs. In this study, a simple, rapid, and accurate method was established to determine 22 triazole pesticide residues in Zhebawei. An improved QuEChERS method was used for sample pretreatment, and Rhizoma Atractylodis Macrocephalae was used as a representative sample. The sample was extracted with acetonitrile to eliminate some polar and nonpolar compounds, pigments, and other impurities, and the purification effects of multiwalled carbon nanotubes (MWCNTs), amino-modified multiwalled carbon nanotubes (MWCNTs-NH2), carboxylated multiwalled carbon nanotubes (MWCNTs-COOH), crosslinked polyvinylpyrrolidone (PVPP), zirconium dioxide (ZrO2), 3-(N,N-diethylamino)-propyltrimethoxysilane (PSA), octadecyl (C18), and graphitized carbon black (GCB) were compared. MWCNTs-COOH and C18 were selected as the purification adsorbents, and their dosages were systematically optimized. The combination of 10 mg of MWCNTs-COOH and 20 mg of C18 was eventually selected as the purification adsorbents. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for analysis, and box graphs were plotted to present the dispersion of each group of recoveries, thus enabling the identification of the data outliers, dispersion distribution, and data symmetry. The established method was systematically verified and showed good linearity over the concentration range of 1-200 μg/L (except for bromuconazole, epoxiconazole, and etaconazole) with correlation coefficients >0.99. The average recoveries of the 22 pesticides at spiked levels of 10, 20, 100, and 200 μg/kg were in the range of 77.0%-115% with relative standard deviations (RSDs) <9.4%. The limits of detection and quantification were 1-2.5 μg/kg and 10-20 μg/kg, respectively. The applicability of the developed method to other herbals was investigated at 100 μg/kg, and the average recoveries of the target pesticides in different matrices ranged from 76.4% to 123% with RSDs <12.2%. Finally, the method established was used to detect triazole pesticide residues in 30 actual Zhebawei samples. The results showed that triazole pesticides were present in Bulbus Fritillariae Thunbergii and Dendranthema Morifolium. Difenoconazole was detected in Bulbus Fritillariae Thunbergii at contents ranging from 41.4 μg/kg to 110 μg/kg, while difenoconazole, myclobutanil, triadimenol and propiconazole were detected in Dendranthema Morifolium at contents ranging from 16.1 μg/kg to 250 μg/kg. The established method can meet the requirements for the accurate quantitative analysis of triazole fungicides in Zhebawei.

Functional Nanocomposites in the Development of Flexible Armor

The idea of flexible body armor has been around for many years. Initial development included shear thickening fluid (STF) as a backbone polymer to impregnate ballistic fibers such as Kevlar. At the core of the ballistic and spike resistance was the instantaneous rise in viscosity of STF during impact. Increase in viscosity was due to the hydroclustering of silica nanoparticles dispersed in polyethylene glycol (PEG) through a centrifuge and evaporation process. When STF composite was dry, hydroclustering was not possible due to absence of any fluidity in PEG. However, particles embedded within the polymer, covered the Kevlar fiber and offered some resistance to spike and ballistic penetration. The resistance was meagre and hence, the goal was to improve it further. This was achieved by creating chemical bonds between particles, and by strongly attaching particles to the fiber. PEG was replaced with silane (3-amino propyl trimethoxysilane), and a fixative cross-linker, Glutaraldehyde (Gluta), was added. Silane installed an amine functional group on the silica nanoparticle surface, and Gluta created strong bridges between distant pairs of amine groups. Amide functional groups present in Kevlar also interacted with Gluta and silane to form a secondary amine, allowing silica particles to attach to fiber. A network of amine bonding was also established across the particle-polymer-fiber system. In synthesizing the armor, silica nanoparticles were dispersed in a mixture of silane, ethanol, water, and Gluta, maintaining an appropriate ratio by weight, and using a sonication technique. Ethanol was used as a dispersion fluid and was evaporated later. Several layers of Kevlar fabric were then soaked with the admixture for about 24 h and dried in an oven. Armor composites were tested in a drop tower according to NIJ115 Standard using spikes. Kinetic energy at impact was calculated and normalized with the aerial density of the armor. NIJ tests revealed that normalized energy for 0-layer penetration increased from 10 J-cm2/g (STF composite) to 220 J-cm2/g for the new armor composite, indicating a 22-fold enhancement. SEM and FTIR studies confirmed that this high resistance to spike penetration was due to the formation of stronger C-N, C-H, and C=C-H stretches facilitated by the presence of silane and Gluta.

Effect of different organic layered double hydroxides on the anti-aging property of bitumen

Two organic layered double hydroxides (LDHs) were synthesized and utilized to enhance the anti-aging property of bitumen. Fourier infrared spectroscopy and X-ray diffraction showed that sodium dodecyl sulfate was intercalated into the interlayers of LDHs (I-LDHs), and γ-(2,3-Epoxypropoxy)propyltrimethoxy silane was chemically grafted onto the surface of LDHs (S-LDHs). Compared with LDHs, organic LDHs possessed better compatibility and organic LDHs modified bitumen exhibited better performance in high-temperature regions, especially S-LDHs. After aging, the rheological properties dramatically deteriorated. The content of aromatic in bitumen evidently decreased, and the asphaltene noteworthy increased, the colloid structure verged on the gel system. The incorporation of LDHs could relieve the damage of aging on the rheological properties and colloid structure, and strengthen the anti-aging property of bitumen. Moreover, the consequence of LDHs had been further enhanced obviously after organic modification, and S-LDHs exhibited more excellent performance compared with I-LDHs.

Synthesis of functionalized metal-organic framework metal-organic framework (MIL-53)/Chitosan for removing dye and pharmaceuticals

Herein, an eco-friendly biocomposite (metal-organic framework (MIL-53)/Chitosan (biological macromolecule)) was synthesized. MIL-(Fe) (Material Institute of Lavoisier: metal-organic framework) was synthesized and denoted as MIL-53A. The material was modified with different amounts of 3-amino propyl trimethoxy silane for preparing different MILs-53A/NH2. Finally, the surface functionalized metal-organic framework and biological macromolecule (SFMOF/BM) biocomposite was synthesized and characterized using XRD, FESEM, TEM, EDS, BET, TGA, FTIR, and Raman and used to remove emerging pollutants (Direct Red 23 and pharmaceuticals (tetracycline and doxycycline)). Adsorption obeyed a pseudo-second-order kinetic model. The adsorption capacity of the MIL-53A and MIL-53A/NH2 was 3,333 and 10,000 mg/g, respectively. SFMOF/BM had the highest adsorption capacity (12,500 mg/g). Adsorption performance remained high even after five regeneration cycles. The results indicated that SFMOF/BM biocomposite could be used as an environmentally friendly adsorbent of dye and pharmaceuticals. The SFMOF/BM could provide multiple non-covalent interactions to remove different organic pollutants, in which both π-π interactions/stacking and H-bonding are suggested to be responsible for the adsorption of dye, tetracycline, and doxycycline.

The Effect of C/Si Ratio and Fluorine Doping on the Gas Permeation Properties of Pendant-Type and Bridged-Type Organosilica Membranes.

A series of pendant–type alkoxysilane structures with various carbon numbers (C1–C8) were used to fabricate sol–gel derived organosilica membranes to evaluate the effects of the C/Si ratio and fluorine doping. Initially, this investigation was focused on the effect that carbon-linking (pendant–type) units exert on a microporous structure and how this affects the gas-permeation properties of pendant–type organosilica membranes. Gas permeation results were compared with those of bridged–type organosilica membranes (C1–C8). Network pore size evaluation was conducted based on the selectivity of H2/N2 and the activation energy (Ep) of H2 permeation. Consequently, Ep (H2) was increased as the C/Si ratio increased from C1 to C8, which could have been due to the aggregation of pendant side chains that occupied the available micropore channel space and resulted in the reduced pore size. By comparison, these permeation results indicate that pendant–type organosilica membranes showed a somewhat loose network structure in comparison with bridged–type organosilica membranes by following the lower values of activation energies (Ep). Subsequently, we also evaluated the effect that fluorine doping (NH4F) exerts on pendant−type [methytriethoxysilane (MTES), propyltrimethoxysilane (PTMS)] and bridged-type [1,2–bis(triethoxysilyl)methane (BTESM) bis(triethoxysilyl)propane (BTESP)] organosilica structures with similar carbon numbers (C1 and C3). The gas-permeation properties of F–doped pendant network structures revealed values for pore size, H2/N2 selectivity, and Ep (H2) that were comparable to those of pristine organosilica membranes. This could be ascribed to the pendant side chains, which might have hindered the effectiveness of fluorine in pendant–type organosilica structures. The F–doped bridged–type organosilica (BTESM and BTESP) membranes, on the other hand, exhibited a looser network formation as the fluorine concentration increased.

The influences of silane coupling agents on the heat and moisture resistance of basalt fibre‐reinforced composites

Basalt fibre composite materials have shown good application prospects in electrical equipment, but their reliability can be affected by damp-heat ageing. In this work, the interface, mechanical, and electrical properties of basalt fibre composites treated with three coupling agents via damp-heat ageing were compared. Molecular simulations were conducted to reveal the damp-heat ageing mechanism of the composites. The results show that γ-aminopropyl triethoxy silane (KH-550) and γ-glycidoxy propyl trimethoxy silane (KH-560) perform better as coupling agents as they form bonds with the matrix resin, compared with γ-methacryloxy propyl trimethoxy silane (KH-570). After the damp-heat ageing treatment, the hydrolysis of the defects of the amino groups in the interface of the KH-550-treated sample can weaken its mechanical properties and insulation properties greatly. The interface layer of the KH-560-treated sample is mostly composed of carbon–oxygen single bonds and methylene groups with its interface structure more stable, which endows the sample with better stability of its mechanical and insulating properties. Therefore, KH-560 is a more suitable coupling agent for processing basalt fibres to be used in electrical equipment.

Combined effect of interfacial modification and α-ZrP reinforcement on the tribological properties of PPS fabric/phenolic composites

The high strength of polyphenylene sulfide (PPS) fiber subserves the potential application of PPS fabric composites in the field of tribology, but its interfacial adhesion restricts tribological properties. In this research, the 3-(2, 3-epoxy propoxy) propyl trimethoxy silane (KH560) was used to construct a micro-interface on the surface of the fabric, which can significantly enhance the surface roughness and functional groups. Furthermore, the incorporation of Alpha-zirconium phosphate (α-ZrP), a two-dimensional material with excellent thermal stability and chemical resistance, contributed to ameliorate thermal properties of the fabric composites. The results show that the bonding and tensile strength of the modified fabric composites are increased by 32.6% and 35.8%, respectively. More importantly, the wear rate of the modified fabric composites is reduced by 58.5% compared with the original fabric composites.

Study on epoxy resin modified by hyperbranched polysiloxane containing active amino group and its properties

A novel phosphorous/silicon hybrid containing active amino was synthesized by bisphenol F epoxy resin modified by 0-(2,5-Dihydroxyphenyl)−10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (ODOPB) and hyperbranched polysiloxane (APTMS-HPSi). At first, APTMS-HPSi was synthesized by a simple reaction among aminoethylamino propyltrimethoxy silane (APTMS) and tripropylene glycol (TPG). ODOPB was used to modify bisphenol F epoxy resin. Then add different content of APTMS-HPSi to the phosphorus-containing modified epoxy resin (P-EP). Fourier Transform Infrared (FTIR) Spectroscopy was used to characterized the chemical structure of APTMS-HPSi. The effects of APTMS-HPSi content on key properties was systemically investigated. Results showed that the addition of APTMS-HPSi and ODOPB effectively improve the toughness and liquid oxygen compatibility. With the increase content of APTMS-HPSi, char yield and limited oxygen index (LOI) value of the cured resin increased, and the liquid oxygen sensitivity coefficient (IRS) decreased. The elongation at break was increased 45.32% by only 6wt% loading with APTMS-HPSi in epoxy resin, and at the same time the IRS of the modified resin was reduced from 7% to 0%. When the addition amount was 6wt%, the fracture elongation, impact strength and fracture toughness KIC were increased by 52.1%, 81.8% and 54.3% respectively. Therefore, adding phosphorus and hyperbranched polysiloxane to the resin can improve the liquid oxygen compatibility and toughness of the epoxy resin at the same time.

A novel anti-clay silane-modified polycarboxylate superplasticizer: Preparation, performance and mechanism

This article proposes a low-temperature free radical polymerization method of anti-clay silane-modified polycarboxylic superplasticizer (S-PCE). Through molecular structure design, strong adsorption silane coupling agent (γ-methylacrylloxy propyl trimethoxysilane, KH570) was introduced in S-PCE. A series of tests and theoretical studies were carried out to obtain chemical structure characterization, dispersion ability, montmorillonite (MMT) tolerance and adsorption behavior of S-PCE. The results showed that compared with the traditional methylallyl alcohol polyoxyethylene ether (HPEG) type PCE (H-PCE) and low clay-sensitivity Naphthalene-based superplasticizer (BNS), S-PCE possessed better dispersion and fluidity retention ability of cement particles in clay-involved environment, and could appropriately improve mechanical properties of concrete. It is mainly due to that silanol (Si-OH) groups can be dehydrated and bonded to silanol on the surface of cement particles and MMT. Thus, the competitive adsorption advantage of MMT was lowered, the possibility of S-PCE binding with cement particle was greatly improved and the intercalation of polyoxyethylene side chain was avoided.

Modeling the catalytic conversion of anthracene oil fraction to light aromatics over mesoporous HZSM-5

Silanization of zeolite units has been proved to be an effective way to improve the hierarchical porosity of HZSM-5. Mesoporous HZSM-5 (YJGW-X: X = 0, 5, 10) were synthesized by adopting phenyl amino propyl trimethoxy silane (YJGW) with different addition (0 wt%, 5 wt% and 10 wt%), followed were applied to investigating the interaction between the compounds of various categories during the conversion process of anthracene oil fraction of low temperature coal tar. Model compounds (MCs), which including naphthol (Nap-ol), methyl naphthalene (Nap-met), methyl anthracene (Ant-met) and C22 alkanes (C22), are selected as raw materials to investigate the conversion progress of anthracene oil fraction of low temperature coal tar using Py-GC/MS. Results show that YJGW addition has a significant role on the acidity and pore size. Besides, the higher aromatic selectivity exhibited by YJGW-5 and YJGW-10 compared to YJGW-0 in the catalytic pyrolysis of single MCs indicates that the addition of YJGW does facilitate the hydrocracking of polycyclic aromatics hydrocarbons to prepare small reactive molecules. When mixed MCs pyrolyzed using YJGW-X, the experimental yield of BTEXN (benzene, toluene, ethyl-benzene, xylene and naphthalene) is higher than theoretical one. When pyrolyzed at 450 °C, the highest experimental yield (2578.35 mg/kg) of BTEXN is obtained using YJGW-10, owing to its appropriate pore structure and acidity. Moreover, the possible formation mechanism of BTEXN derived from MCs catalytic pyrolysis was proposed on the basis of structural features and catalytic performances of YJGW-X.