Advanced Materials Research Vols. 989-994

Abstract: Sewage sludge is difficult to degrade in anaerobic digestion systems and pretreatments have been shown to speed up the hydrolysis stage. In this paper sludge anaerobic digestion experiments with peracetic acid as a pretreatment were carried out and the effects of acid pretreatment using peracetic acid on subsequent digestion were investigated. It has been proved that this treatment effectively leads to a solubilisation of organic material and thus leads to a increase of soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) concentration. Besides, the SV of sludge was reduced and the settling characteristics of sludge were improved. But high dosage of peracetic acid lead to a decrease in biogas production and the proper dosage was 20 g/kg DS. It can be concluded that sludge anaerobic digestion with peracetic acid pretreatment is an effective method for biomass material transformation.

Abstract: A series of multiblock copolymers based on sulfonated poly (arylene ether sulfone) (bSPAES-SF) with highly rigid hydrophilic sulfonate blocks and flexible hydrophobic blocks were successfully synthesized by the condensation of sulfonated decafluorobiphenyl-terminated oligomers and the hydroxyl-terminated oligomers. The former oligomers were sulfonated by fuming sulfonic acid. The bSPAES-SF membranes with IEC of 1.26-1.70 mmol/g exhibited high proton conductivity, hydrolytic and dimensional stability.

Abstract: This paper focuses on discussing the principle of detecting carbon and sulphur by using infrared absorption method, characteristics of high-frequency heating, system blank value, and method for detecting trace carbon and sulphur.

Abstract: The effect of carboxyl density (the ratio of acrylic acid and polyoxyethylene ether) upon the performance, molecular weight, and monomer conversion rate of polycarboxylate (PCE) were investigated by slump test, Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC), respectively. The results showed that with carboxyl density increased from 2:1 to 7:1, molecular weight of PCE increased from 7968.5 to 13930.1 and the molecular weight distribution coefficient increased from 1.5 to 2. The HPLC date indicated carboxyl density does not affect the rate of monomer conversion. Test of the fluidity of cement pastes displayed that as carboxyl density was 4.0:1, PCE show the optimal dispersion and dispersion-retaining ability.

Abstract: A series of copolymers modified with oxidized starch containing maleic anhydride (MA), styrene sulfonic sodium (SSS) and oxidized starch (OS) were synthesized by the free-radical polymerization. The polymerization is initiated by ammonium persulfate. The effects of content of monomer and initiator, reaction time, reaction temperature on dispersion ability for Fe₂O₃ were investigated by single factor experiment. The dispersion ability for Fe₂O₃ measured through UV spectroscopy was studied. The experimental results show that the copolymer has good dispersion ability for Fe₂O₃ when the mass proportion of monomers is OS:SSS:MA = 1:3:1, the mass fraction of initiator in total monomers is 10 %, reaction time is 5 h, and the reaction temperature is 70 ^oC. The morphology of the copolymer was observed by scanning electron microscope (SEM). The experimental results indicate that the prepared copolymer modified with oxidized starch could be used in the corrosion inhibitor of high temperature water.

Abstract: The corrosion inhibitor modified with acid activated attapulgite (CIATP) was prepared with acid activated attapulgite (HATP), styrene sulfonic sodium (SSS), maleic anhydride (MA) as monomers, water as solvent and ammonium persulfate as initiator. The effects of mass ratio of monomer, reaction temperature, the content of initiator and reaction time of preparing CIATP were investigated. The influences of the prepared CIATP concentration, time, pH and temperature of the system on the dispersing ferric oxide efficiency were also investigated. The obtained results showed that the prepared CIATP had excellent efficiency of dispersing ferric oxide, and nearly 98.98 % of dispersing ferric oxide efficiency was obtained. The experimental results indicate the corrosion inhibitor CIATP could be used in the corrosion inhibitor of high temperature water.

Abstract: An in-situ polymerization method was used for the preparation of a novel stir bar based on neodymium magnet (Nd₂Fe₁₄B) powders. The processes were carried out by several steps including the enwrapping of Nd₂Fe₁₄B, the modification of the enclosed Nd₂Fe₁₄B, and the form of organic polymers on the surface of the modified powders. It was successfully used to enrich the plasticizers in water sample by stir bar sorptive extraction (SBSE). The experimental conditions for SBSE, such as the choice of extraction sorvents, salt concentration, extraction and desorption time were optimized in detail. Coupled to high performance liquid chromatography (HPLC), the recoveries of dibutyl phthalate (DBP), dimethyl phthalate (DMP), diethyl phthalate (DEP) were 89.2%~92.1%, 91.9%~96.6% and 94.3%~96.7%, respectively; the linear relationships between the concentration 5 μg/L and 800 μg/L for DBP were obtained; the limits of detection ranged from 0.09 μg/L to 0.21 μg/L in the optimal conditions.

Abstract: The growth of CVD diamond film was simulated by using revised KMC method. The simulation was conducted at CH₃ radical concentration (0.01%-0.03%) and atomic hydrogen concentration (0.01%-0.5%). The results showed that: The CVD diamond film growth under revised KMC method is superior, which is in good agreement with the experimental results. The concentration of CH₃ ([CH₃]) and the concentration of atomic H ([H]) can produce important effects on the film deposition rate, surface roughness and the concentration of atom H embedded in the film.

Abstract: The polymer-based propellant is a typical viscoelastic material. Better understanding of the relaxation properties of the propellant in the storage conditions is of great importance for predicting the lifetime. Due to the component complexity of the composite propellants, the transformation relation between the relaxation modulus and the complex modulus may not be suitable for all kinds of propellants. In the present work, we focused on the transformation of the relaxation modulus and complex modulus for the HTPB propellant. The master curves for the relaxation modulus and the storage modulus of the aged/unaged HTPB propellants were obtained by performing the stress relaxation tests and DMA tests, respectively. It was found that there existed a great difference in the double logarithmic plot between relaxation modulus and storage modulus master curves. Moreover, the testing results for the relaxation modulus and the storage modulus were well fitted by an empirical transformation relation with three segment-related coefficients. These three coefficients were determined by using the unaged samples, and then were applied to estimate the relaxation modulus of the aged samples. A good agreement between the calculation and the experimental results was also found, revealing that the three coefficients were insensitive to the aging time.

Abstract: For the characteristic that the mechanical properties of resin composite are lower than cast iron, steel fibers are used to improve its properties in this paper. A weak interfacial bonding strength between steel fibers and resin indicates that steel fibers’ property cannot perform well in the polymer. In order to improve the interfacial bonding strength, four methods of surface treatment, phosphating, acid pickling, oxidation, and coupling are applied to steel fibers, and the corresponding pull-off tests are carried out to compare with untreated steel fibers. Research results show that the maximum interfacial bonding strength is increased by 45.1% after coupling treatment.