The effects of borax, sodium gluconate and L(+)-tartaric acid on the hardening behavior and strength development of rapid-hardening calcium sulphoaluminate cement mixed with calcium chloride solution at -10 ℃ were investigated. The results show that the initial and final setting time of rapid-hardening calcium sulphoaluminate cement mixed with calcium chloride solution prolonge to 25 min and 28 min with 0.6% borax at -10 ℃, respectively. However, the setting time of pastes with sodium gluconate or L(+)-tartaric acid does not extremely change. The strength gradually decreases in the samples with increasing the dosages of borax and sodium gluconate at different ages. A maximum reduction of 25.5 MPa occurs in those samples. The strength of samples containing L(+)-tartaric acid sharply decreases. A reduction of 10.9 MPa in 3-day samples containing 0.3% tartaric acid and 27.3 MPa in 28-day samples containing 0.6% tartaric acid occur. The presence of 0.6% borax does not change the morphology of ettringite at 1 d, but decreases the amount of ettringite by 5.31%. A short column-like ettringite in the samples with sodium gluconate and a needle-shaped-like ettringite in the samples with L(+)-tartaric acid are detected, respectively. However, the amount of ettringite in those two samples above has no remarkable change. Borax is a suitable retarder for calcium sulphoaluminate cement at -10 ℃ because of the feasibility of setting prolongation and the acceptable strength reduction. Sodium gluconate and L(+)-tartaric acid have a slight effect on the setting time but change the ettringite morphology and deteriorate the strength.

It is necessary to concern the safe utilization of the fluorine-containing sludge disposed in landfills due to its possible leaching toxicity. The effect of physicochemical performance of fluorine-containing sludge, used in cement kiln on the cement properties and environmental safety was investigated by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, immersion extraction and leaching toxicity tests. The results show that the fluorine content of fluorine-containing is 15.3% with a small amount of heavy metal ions (e.g. Cr, Mn, Ni, Cu, Zn, etc.). Fluorite is the major mineral phase, and secondary mineral phases are sphalerite and nantokite. Fluorine in fluorine-containing sludge is mostly calcium fluoride, and its content (mass fraction) reaches approximately 30.0% in the sludge. In addition, the leaching toxicity of F and Cr is below the toxicity restriction. However, the leaching toxicity of Ni, Cu and Zn is above the toxicity restriction. Therefore, the fluorine-containing sludge is subordinate to a heavy metal solid hazardous waste. Also, the incorporation of fluorine-containing sludge assists the formation of alite, and improves slightly the compressive strength of cement mortars. Meanwhile, 2.0% (mass fraction) fluorine-containing sludge doped cement could not cause the secondary environment risk after curing age of 28 d.

The measurement scheme of rheological parameters of fresh cement-based materials and the processing method of measured data were given. The feasibility of different methods, i.e., using of the shear stress and shear strain rate displayed on rheometer, some approximate equations and solution to the Couette inverse problem was analyzed for calculating the rheological parameters of fresh cement-based materials. The analysis results show that the solution to the Couette inverse problem as a reasonable method can be used to obtain the rheological parameters of fresh cement-based materials. The corresponding calculation procedure was given. The influence of plug flow on the calculation of rheological parameters of fresh cement-based materials could be considered. The calculation of rheological parameters of fresh cement-based materials could be more accurate for the measured data in the absence of plug flow.

Ultraviolet labeling technology was used to enhance the ultraviolet absorption of polycarboxylate, and then the technology of ultraviolet absorption spectrum and total organic carbon analysis is used together to effectively distinguish respective adsorption behavior of polycarboxylate and quaternary ammonium salt cation molecules when they exist at the same time, and the interaction between three typical quaternary ammonium salt cations and polycarboxylate in cement montmorillonite system is studied systematically. The results show that the adsorption of polycarboxylate on the cement surface is not affected by the small molecular quaternary ammonium salt, the Gemini quaternary ammonium salt can promote the adsorption of polycarboxylate, the polymer quaternary ammonium salt can inhibit the adsorption of polycarboxylate water reducer on the cement surface. And the three quaternary ammonium salts can effectively inhibit the adsorption of polycarboxylate water reducer on the surface of montmorillonite when doped as 2.5×10^-4. The effect of Gemini quaternary ammonium salt and polymer quaternary ammonium salt is more obvious. The inhibition effect of Gemini quaternary ammonium salt is stronger at low dosage, while the inhibition effect of polymer quaternary ammonium salt at high dosage is better.

A zeolite molecular sieve was synthesized with oil shale ash from Yaojie, China. The effects of liquid-solid ratio (A), crystallization time (B) and crystallization temperature (C) on the cation exchange capacity (Y) of synthesized zeolite were investigated based on the Box-Behnken Design (BBD) of a response surface method. The results show that the model established by the response surface method has a good predictability for the Y value of zeolite, and the Y value of zeolite is improved after optimization. Each factor and their interaction have effects on the Y value of synthesized zeolite, and the order of the factor effect is A, C, and B and the order of interaction effect is AC, BC, and AB. The Na-X zeolite can be synthesized under optimum conditions (i.e., alkali melting temperature of 650 ℃, ash-alkali ratio of 1∶1.7 g/g, liquid-solid ratio of 4.5∶1 mL/g, crystallization time of 25.2 h, and crystallization temperature of 83 ℃). The Y value of zeolite synthesized under optimum conditions is 52.44 mg/g.

A flexible expanded vermiculite (FEV) with a high expansion ratio was prepared by a chemical-microwave method with industrial vermiculite as a raw material. The optional process and relationship between expansion rate and flexibility were investigated. The results show that the expansion ratio of FEV prepared by chemical-microwave heating is up to 36.36. The screen tailings yield of FEV samples is negatively correlated to the expansion rate, and the sharp expansion action can improve the exfoliation ability of expanded vermiculite particles, thereby reducing the flexibility of FEV sample particles. The interior of FEV is loose and porous, the pores are evenly distributed and the intact layered structure is still maintained. The thickness of the inner wall forming the narrow slit is 50-200 nm. The FEV is a low-cost precursor of vermiculite nanomaterial, which can be mechanically exfoliated to prepare vermiculite nanomaterial based on its lamellar dissociation characteristic.

Hexagonal mesoporous silica (H-mSiO₂) particles were prepared via an alcohol/water mixed reaction system using cetyltrimethyl ammonium bromide as a template. The resultant products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform spectroscopy, thermogravimetric analysis-differential scanning calorimetry, and nitrogen adsorption/desorption measurements. As an alcohol/water volume ratio decreases slowly, the morphologies of samples change from spherical/ellipsoidal to spherical and then to necked or peanut-like. Based on the polishing tests over oxide films (about 208 nm), the developed H-mSiO₂ abrasives contribute to the reductions of surface roughness and topographical variation, compared to non-porous sphere SiO₂ (sSiO₂) particles. The root-mean-square roughness of oxidized silicon wafers reduces from (1.27±0.15) nm to (0.25±0.01) nm after polishing with H-mSiO₂ containing spherical and ellipsoidal particles. The maximum asperity height in sectional profiles decreases from 3.59 nm to 0.72 nm, and the maximum valley depth also reduces from 3.16 nm to 0.69 nm. Moreover, H-mSiO₂ abrasives with uniform spherical shapes achieve a removal rate of (223±17) nm/min.

An acid leaching solution containing aluminum ions was obtained by a sulfuric acid leaching process after calcining clinkers using coal fly ash as a raw material. Aluminum hydroxide was precipitated through adjusting the pH value of solution and used as an aluminum source. Magnesium aluminum hydrotalcite was synthesized via hydrothermal reaction with magnesium oxide and sodium carbonate. Based on the results by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy, magnesium-aluminum hydrotalcite with a good crystallinity, a pure phase and a complete lamellar structure can be synthesized under the hydrothermal conditions (i.e., mole ratio n(MgO)∶n(Al(OH)₃)∶n(Na₂CO₃) of 2∶1∶1, at 160 ℃ for 14 h). In addition, the feasibility of adsorbing phosphorus by Mg-Al hydrotalcite was also investigated. The removal rate can reach 97.4% when the concentration of phosphorus solution is 20 mg/L, the dosage of Mg-Al hydrotalcite is 0.7 g and pH value is 4-10.

The As₄₀S₆₀ core and As₃₉S₆₁ inner and outer cladding glasses were fabricated with the dynamic distillation purification process and melt-quenching method. The cladding tube was prepared by a computerized numerical control precision drilling machine, and then the fiber with the cladding and core diameter of 124 μm and 5 µm was produced by the combination of the secondary tube in rod method. The refractive index of core and cladding, cross-section dimensions, loss and bending loss of the fiber was measured and analyzed. The results show that the N_A of the fiber is less than 0.425 in the wavelength range of 2.5-10.0 µm and its concentricity between core and cladding is good. The fiber has the minimum loss of 1.7 dB/m at 1 550 nm, and single-mode mode in the wavelength range of >2.5 µm. The fiber transmission losses increase sharply when the bending radius reduces to 20 mm.

An organic-inorganic composite polymer electrolyte (CPE) was constructed via introducing an active filler of Na-β''-Al₂O₃ into a solid-state polymer electrolyte (SPE) composed of poly(ethylene oxide) (PEO) and sodium bis(trifluoromethanesulfonyl)-imide (NaTFSI). The phase composition, ionic conductivity, Na⁺ transference number, and electrochemical stability were investigated. The electrochemical properties of SPE and CPE in Na|Na₃V₂(PO₄)₃@C solid-state sodium batteries were obtained. The results show that the CPE has a greater Na⁺ transference number of 0.71 than SPE (i.e., 0.19) and a higher Na⁺ conductivity of 8.19×10^-4 S/cm than SPE (i.e., 1.65×10^-4 S/cm) at 80 ℃. The CPE exhibits a superior cycling stability with capacity retentions of 93.9% after 100 cycles at 0.5 C and 74.0% after 500 cycles at 2.0 C in Na|CPE|Na₃V₂(PO₄)₃@C solid-state batteries.