摘要:
A new synthetic method was designed to prepare poly (trimesoyl chloride-co-polyethyleneimine) (PEI-TMC). Characterization of PEI-TMC was investigated by FTIR, SEM, EDS, XPS, TGA, and BET. TGA test revealed that the PEI-TMC had excellent thermal stability. The BET specific surface area (4.74 m(2) g(-1)) and pore diameter of about 9.44 nm indicated that PEI-TMC possessed a mesoporous structure. The adsorption behavior of U(VI) on the PEITMC was investigated. The thermodynamic analysis showed that the process of PEI-TMC adsorption of U(VI) was endothermic and spontaneous, and the adsorption efficiency was better at higher temperatures. The U(VI) sorption on PEI-TMC was conformed to the Langmuir adsorption isotherm and pseudo-second-order kinetic models. The adsorption mechanism of U(VI) with PEI-TMC was systematically elucidated by XPS and FTIR. Under the best condition, the maximum adsorption capacity of PEI-TMC could reach 212.8 mg g(-1) by calculating the Langmuir isothermal model. It indicated that PEI-TMC was a potential adsorbent for the treatment of U(VI)containing wastewater.
摘要:
We systematically designed and developed three novel halogenated aza-octacene derivatives, which have the same pi-conjugated backbone with different terminal halogen groups (F, Cl, Br). These aza-octacene derivatives are synthesized by acid-catalyzed condensation of naphthalene-bisisatin with 4,5-dihalo-1,2-phenylenediamine. The in-depth experimental and theoretical analyses on these molecules, using the non-halogenated system as a reference, allowed us to understand the impact of halogenation on electronic and optical properties. Both electronic affinity (EA) and ionization potential (IP) are increased through peripheral halogen substitution. Chlorination enhances the EA more effectively compared with fluorination and bromination. Micro-crystal devices based on the bromine substituted aza-octacene derivative show only p-type charge transport behavior. In contrast, the chlorinated and the fluorinated aza-octacene derivatives exhibit ambipolar charge transport.
摘要:
Poly(cyclotriphosphazene-co-polyethyleneimine) microspheres with the solid structure were synthesized by precipitation polymerization method for the separation of highly toxic uranium(VI). The structure and morphology of the prepared microspheres were analyzed via FTIR, SEM-EDS, TEM and BET. The optimal adsorption conditions were also investigated, and the maximum adsorption capacity was 274.2 mg g(-1). The experimental results showed that the adsorption kinetics conformed to the pseudo-second-order kinetics and was in good agreement with the Langmuir adsorption isotherm model. Removal of uranium(VI) ions was achieved by the complexation between the amino groups on the adsorbent and uranyl ions.
摘要:
Poly(cyclotriphosphazene-co-4,4′-diaminodiphenyl ether) crosslinked microspheres with active amino groups on the surface were prepared by one-step precipitation polymerization method. The as-prepared material were characterized by means of FTIR, XPS, XRD, EDS and SEM. The effects of pH, time of contact, dosage, initial concentration and temperature on the adsorption of uranium(VI) by the crosslinked microspheres were studied, and the adsorption mechanism was elucidated. Under the optimized adsorption conditions, the adsorption removal efficiency reached 97.03%. The experimental results fit the Langmuir isotherm model and adsorption processes comply with the pseudo-second-order kinetic model. Thermodynamic data revealed that the adsorption behavior of uranium(VI) on the microspheres was spontaneous and exothermic.
摘要:
Purpose The purpose of this paper is to study the tribological properties of a thiazole derivatives (T561), overbased alkyl benzene calcium sulfonate (T106A) compounded with T561 and overbased alkyl benzene magnesium sulfonate (T107) compounded with T561 in rapeseed oil (RSO). Design/methodology/approach A four-ball machine was used to evaluate the tribological properties of each compound and their combinations with T561 in RSO. Scanning electron microscopy, EDX and X-ray photoelectron spectroscopy were applied to analyze the tribofilm formed on the worn surfaces. Findings Results of tribotesting demonstrated that synergistic effects exist between the overbased sulfonates, T106A and T107, and the thiazole derivative, T561. The texts of tribofilm indicated that iron sulfide and iron oxides exist in T561 single agent lubricant film and two composite additives lubricant film, and no sulfates were detected. It suggested that the addition of alkyl benzene sulfonate did not hinder the formation of iron sulfides and iron oxides. Meanwhile, CaSO4 (MgSO4) and CaCO3 (MgCO3) were detected on the worn surface of the composite additives, which were not detected on the single agent friction surface. Originality/value A tribofilm mainly contains CaSO4 (MgSO4) and CaCO3 (MgCO3) formed on the worn surfaces, which is responsible for excellent extreme pressure and anti-wear properties of the compound agents because of their high melting point and high shear stress.
期刊:
INDUSTRIAL LUBRICATION AND TRIBOLOGY,2017年69(5):621-626 ISSN:0036-8792
通讯作者:
Wang, Yanfei
作者机构:
[Hu, Xueping; Liu, Jing; Wang, Yanfei] Univ South China, Dept Chem & Chem Engn, Hengyang, Peoples R China.;[Tang, Pengfei] Hengyang Jinhua Sci & Technol Grp, Hengyang, Peoples R China.
通讯机构:
[Wang, Yanfei] U;Univ South China, Dept Chem & Chem Engn, Hengyang, Peoples R China.
关键词:
Additives;Environment;Friction coefficient;High temperature;Environmental health and safety;Brucite;Lubricant;Water-based
摘要:
Mg(OH)2 whose average particle size is 10 m was chosen as a base material without further modification and pretreatments. On the HT-1000 high-temperature tribometer, the influence of temperature and lubricant materials on the friction coefficient was studied. The tribological performance at 900�C provided evidence under high temperature for exploring a new lubricant material. Tap water-based brucite lubricant will open a new chapter in the industrial lubrication, effectively avoiding many unfavorable factors caused by graphite lubrication, such as conductivity, pollution and energy loss. Meanwhile, it expanded the application of brucite as flame-retardant agent, catalyst, water treatment agent and so on.