Advanced Materials Research Vols. 557-559

Abstract: Thermo-sensitive microemulsion-based gels (MBGs) were prepared by the addition of Pluronic P123 (PEO₂₀PPO₇₀PEO₂₀) into O/W microemulsion composed of isopropyl myristate (IPM)/Span20/Tween20/H₂O. The results of rheological measurements indicate that the viscoelastic properties of the systems increase and the gelation temperatures decrease with increasing P123 concentration. Fluorescence spectroscopy was used to study the micropolarity of the hydrogel (P123/H₂O), microemulsion and MBGs systems. The results show that the microstructures of microemulsion droplets are maintained in MBGs.

Abstract: Natural Ca-rectorite (Ca-REC) is modified with hexadecyl trimethyl ammonium bromide (CTAB) to get CTAB-rectorite (CT-REC). XRD and SEM analytical method were used to study the change of rectorite in external morphology and internal structure. The results showed that the layer structure of CT-REC was looser and the basal spacing was obviously bigger than Ca-REC. The ability of RECs in removing microcystis aeruginosa (M. aeruginosa) was investigated through long-term and short-term study. The results of short-term study showed that compared with Ca-REC removing 10% of the algae at the concentration of 0.1g/L in 10h, CT-REC removed more than 98% of the algae under the same condition. The results of long-term study showed that Ca-REC had acute effect on algae but couldn’t terminate cell growth while CT-REC could put an end to the regrowth of algae and control the Harmful algal blooms effectively.

Abstract: In order to prepare a novel superabsorbent resin based on cellulose, straw pulp cellulose was used as raw material, through etherification preparation of carboxymethyl cellulose, K2S2O8-Na2SO3 oxidationredox system as an initiator, acrylic acid, acrylamide as grafting monomer, crosslinking agent N, N-methylenebisacrylamide were used to synthesize the high water absorbent resin. The effects of reaction conditions to superabsorbent resin were studied using water absorbencies as evaluation standard, the optimum preparation technology was decided.

Abstract: Grafting vinyl monomers onto natural cellulose become a preferred method to derive water retaining agent because it afforded unique environmental and commercial advantages. In current work, a series of water retaining agent were prepared by radical solution polymerization of cellulose, partially neutralized acrylic acid and acrylamide using grafted agents as an initiator and N, N-methylenebisacryl- amide as a crosslinker. Fourier transform infrared spectroscopy spectra proved that acrylic acid and acrylamide were grafted onto cellulose backbone and N, N-methylenebisacryl- amide participated in polymerization. The effects of reaction conditions of reaction temperature and initiator amount to water retaining agent were studied using water absorbencies as evaluation standard, the optimum preparation technology was decided.

Abstract: Alginate fiber is a new type of green functional textile materials that can biodegradation, these years more and more people pay great attention to it for its excellent properties of antibacterial, moisture-absorption property etc. On the basis of experimental examination, the length wise appearance and cross section appearance , the tensile properties, the moisture-absorbency, property ,acid resistance and alkali resistance etc. of the alginate fiber are studied. The conclusions gained in this paper have important reference value to the development of alginate fiber product and its processing.

Abstract: A series of fluorescence compounds, 4-benzofuranyl-1,8-naphthalimides, were prepared through cycloaddition reaction from 4-ethynyl-1,8-naphthalimides and o-iodophenols which catalyzed by a Pd(PPh3)2Cl2 / CuI system under mild conditions. The intermediate material, 4-ethynyl-1,8- naphthalimide, was synthesized from 4-bromo-1,8- naphthalimide and trimethylsilyl- acetylene. The absorption and fluorescence spectra of 4-benzofuranyl-1,8- naphthalimides were studied and the quantum yields were measured. The maximum UV/vis absorption spectra were in the range of 375-400 nm and the maximum emission spectra were in the range of 470-510 nm. The electro- luminescent properties were also mensurated through a doped electroluminescent device which contains 1% 1,8-naphthalimides and 99% CBP (4,4'-N,N'-dicarbazole-biphenyl), It’s shown the maximum brightness reached 3700 cd/ m2 at 22.5V.

Abstract: In this study, hydrophobic SiO₂ aerogel was prepared through fractional hydrophobic modification and ambient pressure drying of the raw material, tetraethoxysilane (TEOS) under ultrasonic wave and using trimethyl chlorosilane as modifier and acid catalyst in the process of sol-gel and acid-base catalysis. SiO₂ aerogels were analyzed and compared using scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller analysis method, Fourier transform infrared spectroscopy, X-ray diffraction. The results indicate that by adopting the ultrasonic wave, the specific surface area of SiO₂ aerogels was 801.71 m²/g. Pore distribution in micro-pore range was 0.5-1 nm. Pore distribution in meso-pore range was 2.0-20 nm. The hydrophobic SiO₂ aerogels with the hydrophobic angle at 160° displayed super hydrophobicity.

Abstract: The effect of La addition on the microstructure and phase transformation behavior of Ti _49.3Ni_50.7 alloy is investigated by optical microscope (OP), scanning electron microscope (SEM), X-ray diffraction analysis (XRD) and differential scanning calorimeter (DSC). The results show that the microstructure of Ti-Ni alloy is changed obviously with La addition, and the microstructure of Ti-Ni alloy containing La at room temperature is made up of the matrix and LaNi phase. La addition firstly increases the martensitic transformation temperatures evidently and the increase of Ms is about 62°C with 1at.% La. Secondly Adding La changes the type of phase transformation behavior of Ti-Ni alloys, and R phase transformation with Rs temperature about room temperature occurs in La added Ti-Ni alloy.

Abstract: By recycling method, the wastes in the nonwoven industry decreases, and simultaneously multiple functions are attached to the nonwoven, leading to varied application of nonwoven. With these purpose, different ratios of recycled sawdust was blended in PU foaming body material, and the optimal ratio was chosen based on the best sound-absorbing property. Additionally, recycled polypropylene (PP) fiber and PP fiber were needle-punched to form PP nonwoven foundation. Ratios of the PP recycled selvages were varying in this process. Afterwards, tensile strength and sound absorption coefficient of nonwoven foundations were both evaluated for optimal nonwoven parameters. Finally, the optimal Sawdust/ PU foaming and PP nonwoven foundation were laminated into a sandwich-structure composite—PP/Sawdust/PU sound-absorbing plank, following characterizations of sound-absorbing property and mechanical property.

Abstract: Starch-graft-polyacrylamide (St-g-PAM) was prepared using a salt media polymerization technique, and characterized by FITR. The type of starch and the synthesis method of different system were studied through the mass of product, the percentage of grafting (PG) and the monomer conversion (MC), and the difference polymerization system. The results showed that the pretreated starch and the salt solution system, respectively, were more advantageous than the raw starch and the aqueous solution system. The intrinsic viscosity, transmittance, product loss, penetration and apparent viscosity of St-g-PAM by salt solution polymerization were 12.49 dL•g^-1, 18.6%, 0.56%, 53.96, 18.40 Pa•S, respectively. The method could get bigger branched-chain molecular than the others with high yield, high monomer conversion, high the percentage of grafting, low product losses and easy post-processing