Mechanism of the effect of modified TiO2 on the strength of gold tailings-based no-fire bricks samples

PurposeThis study aims to prepare UV protection and hydrophobic fabric through modifying cotton fabric by graphene oxide and silane coupling agent. The graphene oxide and silane coupling agent (KH570) are anchored on the cotton fabric by a stable chemical bond.Design/methodology/approachGraphene oxide was prepared by modified Hummers method. The fabric sample was treated with graphene oxide and silane coupling agent KH570 using simple dipping-padding-drying method. The effects of the dosage of graphene oxide, silane coupling agent KH570 and curing temperature were determined by single variable experiment and orthogonal experiment, The UVA and UVB transmittances in ultraviolet light of the sample fabric were characterized, and the contact angle test method with water was used to indicate the hydrophobicity of the sample fabric. The structure and surface of the fabric were analyzed using Fourier-transform infrared spectroscopy and scanning electron microscopy.FindingsThe cotton fabric was successfully modified by graphene oxide and silane coupling agent KH570. Compared with the untreated fabric, the surface of the fabric was smooth, and there was no gap on the fiber. The graphene oxide, silane coupling agent KH570 and cotton fabric combined tightly. The UPF value of the modified fabric was 50+, and the contact angle reached 138.1°. It had excellent UV protection and hydrophobic properties.Research limitations/implicationsAlthough graphene oxide and silane coupling agents KH570 had successfully endowed the cotton fabric with good UV protection and hydrophobic properties, graphene oxide and silane coupling agent KH570 are expensive and used in large quantities. There are certain limitations in the actual life and production process.Practical implicationsAfter treating with silane coupling agent, the hydrophilic fabric treated with graphene oxide is being translated into hydrophobic, and graphene oxide bonded with cotton. The modified fabrics also have excellent UV protection. This fabric can be used for outdoor sports such as clothes and tents.Originality/valueCotton fabric treated with graphene oxide generally by simple dip-dry-cure method is hydrophilic and graphene oxide is easy to drop. The usage of silane coupling agent KH570 as a crosslinking agent to link graphene oxide and cotton fibers has not been reported yet. The modified fabrics have both UV protection and hydrophobic properties.

Construction of high-efficiency fixing structure of waterborne paint on silicate-modified poplar surfaces by bridging with silane coupling agents

Three visualization methods, Schlieren, Shadowgraph, and Mie-scattering, were applied to compare diesel and gasoline spray structures in a constant volume chamber. Fuels were injected into a high pressure/high temperature chamber under the same in-cylinder pressure and temperature conditions of low load in a GDCI (gasoline direct injection compression ignition) engine. Two injection pressures (40 MPa and 80 MPa), two ambient pressures (4.2 MPa and 1.7 MPa), and two ambient temperatures (908 K and 677 K) were use. The images from the different methods were overlapped to show liquid and vapor phases more clearly. Vapor developments of the two fuels were similar; however, different liquid developments were seen. At the same injection pressure and ambient temperature, gasoline liquid propagated more quickly and disappeared more rapidly than diesel liquid phase. At the low ambient temperature and pressure condition, gasoline and diesel sprays with higher injection pressures showed longer liquid lengths due to higher spray momentum. At the higher ambient temperature condition, the gasoline liquid length was shorter for the higher injection pressure. Higher volatility of gasoline is the main reason for this shorter liquid length under higher injection pressure and higher ambient temperature conditions. For a design of GDCI engine, it is necessary to understand the higher volatility of gasoline.

The interface performance of nickel‐titanium (Ni‐Ti) shape memory alloy (SMA) fiber reinforced vinyl ester resin composites was investigated in this work. All the SMA fibers were pre‐treated with H2SO4 and NaOH solution. The fiber surfaces were coated with Al2O3 nanoparticles and silane coupling agent KH550. For comparison, two groups of SMA fibers were coated only with the silane coupling agent or the nanoparticles. Furthermore, the effect of the nanoparticle content on the interface performance of the composites was investigated for Al2O3 nanoparticle contents ranging from 1 wt% to 4 wt%. Scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopy (EDX) were used to study the effect of the surface modifications. The results demonstrate that all the modified methods enhance the interface strength of the SMA/vinyl ester resin, but samples with SMA fibers coated with both the silane coupling agent and 3 wt% Al2O3 nanoparticles have the best interface performance. SEM observations show that the dispersion of nanoparticles increases when the silane coupling agent is added to the composites. POLYM. COMPOS., 39:3040–3047, 2018. © 2017 Society of Plastics Engineers

Disposal of solid waste as building materials: A study on the mechanical and durability performance of concrete composed of gold tailings

Spray dynamics and evaporation in a multihole GDI injector for pulsatile and split injection at elevated ambient pressure and temperature conditions

A magnetic emulsifier is synthesized by using the two-step method. Firstly, Fe3O4 nanoparticles are synthesized and then modified with silane coupling agent 3-(methacryloyloxy) propyltrimethoxysilane (KH-570). Secondly, the final composite particles are synthesized by the reaction between emulsifier octylphenol polyoxyethylene ethe OP-10 (C8H17C6H4O(CH2CH2O)10H) and modified Fe3O4 nanoparticles by silane coupling agent KH-570. After then the products are characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Raman spectroscopy, thermogravimetric analysis (TGA), and X-ray diraction (XRD). The result shows that the mean diameter of Fe3O4 nanoparticles is about 22.7 nm and the silane coupling agent KH-570 can be effectively modified Fe3O4 nanoparticles. In addition, this paper investigated the best hydrolysis conditions of coupling agent and the optimum reaction conditions of silane coupling agent on the Fe3O4 nanoparticles.

Fabrication and characterization of highly hydrophobic rutile TiO2-based coatings for self-cleaning

Numerical study of wall cooling effects on diesel spray combustion characteristics under different ambient conditions

Evaluation of factors affecting mineral carbonation of CO2 using coal fly ash in aqueous solutions under ambient conditions

Simple SummaryInteractions of ligands with proteins are central to all reactions in the biological cell. How such reactions are affected by harsh environmental conditions, such as low temperatures, high pressures, and high concentrations of biologically destructive salts, is still largely unknown. Our work focused on specific salts found on Mars to understand whether the planet’s potentially liquid, water-rich subsurface harbors conditions that are theoretically favorable for life. Our data show that, while magnesium chloride and sulfate do not significantly alter protein–ligand interactions, the perchlorate ion strongly affects protein–ligand binding. However, the temperature and pressure conditions encountered on Mars do not necessarily preclude protein–ligand interactions of the type studied here.Protein–ligand interactions are fundamental to all biochemical processes. Generally, these processes are studied at ambient temperature and pressure conditions. We investigated the binding of the small ligand 8-anilinonaphthalene-1-sulfonic acid (ANS) to the multifunctional protein bovine serum albumin (BSA) at ambient and low temperatures and at high pressure conditions, in the presence of ions associated with the surface and subsurface of Mars, including the chaotropic perchlorate ion. We found that salts such as magnesium chloride and sulfate only slightly affect the protein–ligand complex formation. In contrast, magnesium perchlorate strongly affects the interaction between ANS and BSA at the single site level, leading to a change in stoichiometry and strength of ligand binding. Interestingly, both a decrease in temperature and an increase in pressure favor the ligand binding process, resulting in a negative change in protein–ligand binding volume. This suggests that biochemical reactions that are fundamental for the regulation of biological processes are theoretically possible outside standard temperature and pressure conditions, such as in the harsh conditions of the Martian subsurface.

Vermiculite (VMT) was used as a filler and it was modified with silane coupling agent KH570 to produce OVMT. VMT/PBAT and OVMT/PBAT composite films were prepared using the solution method using polybutylene terephthalate (PBAT) as a matrix. The structure, thermal properties, crystalline properties, rheological properties, cross‐sectional microstructure, and tensile properties and antibacterial properties of the pure PBAT film, VMT/PBAT, and OVMT/PBAT composite films were tested, including comparative analysis. The results showed that VMT was successfully modified with silane coupling agent to produce OVMT. Furthermore, the thermal stability of VMT/PBAT and OVMT/PBAT composite films decreased compared with pure PBAT film. As the content of VMT and OVMT increases, the energy storage modulus and loss modulus of VMT/PBAT and OVMT/PBAT composite films increase, while the loss factor, complex viscosity and crystallinity gradually decrease. Additionally, the tensile strength and elongation at break of VMT/PBAT and OVMT/PBAT composite films decrease. All three films had no effect on Staphylococcus aureus or Escherichia coli. The modification of VMT with the silane coupling agent KH570 improved the compatibility of OVMT with PBAT, resulting in improved mechanical properties of the OVMT/PBAT composite film compared with the VMT/PBAT composite film. The mechanical properties of the OVMT/PBAT‐20% composite film increased by 35.9% in tensile strength and 10.8% in elongation at break compared with the VMT/PBAT‐20% composite film.Highlights VMT successfully modified with silane coupling agent to produce OVMT. The modification promotes the compatibility of the filler with PBAT. VMT modification helps to improve the mechanical properties of composite materials. Vermiculite modification helps to improve the toughness of composite materials.

The surface modification of nano-Sb2O3 particles with silane coupling agent KH-570 was carried out by chemical modification method (CM) and ball milling modification method (BMM). The modification mechanism was also analyzed and discussed. The surface characteristics of modified nano-Sb2O3 particles were characterized by FTIR, TEM, BET and UV absorbance. The results showed that silane coupling agent could chemically anchor onto the surface of nano-Sb2O3 particles though the effect of covalent bond (Sb-O-Si), and the modified nano-Sb2O3 particles exhibited a good dispersive capacity in organic solvent. Comparative modification effect showed that the dispersion of nano-Sb2O3 particles modified by BMM was better than that of CM, due to the secondary aggregations of nano-Sb2O3 particles could be crushed in the ball milling modification process, which provided more reaction chance with silane coupling agent.

Surface modification of filter medium particles with silane coupling agent KH550

The PMN/EP composites were prepared by resin casting method from PMN powder pretreated with silane coupling agent KH-550. The microstructure of the PMN/EP composite was observed by SEM, the damping property and dielectric property of the composite were investigated by dynamic mechanical analyzer and impedance analyzer respectively. In the composite prepared with PMN powder pretreated by 1.5% silane coupling agent, much epoxy resin fragment is attached in the surface of PMN particles. When the silane coupling agent concentration is 1.5%, the composite shows the best damping property. Dielectric analyses suggest that the dielectric constant of the PMN/EP composite decreases with the increase of silane coupling agent content, however the dielectric loss increases with the increase of silane coupling agent content.