Advanced Materials Research Vol. 699

Abstract: Self curable unsaturated polyesters with pendant hydroxyl groups on main chain were synthesized through the polycondensation of maleic anhydride and glycidol at different raw material ratios. The preparation process and self-curing properties were studied. Investigation demonstrated that the unsaturated polyester resin could be self cured through the addition reaction of pendant hydroxyl groups with the double bonds on main chain when it was heated above 150°C without additional cross-linking monomer. This research may contribute to improve air pollution caused by volatile of cross-linking monomers. H-nuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize.

Abstract: A series of new functional polymers which were constituted by Tetraphenylethene(TPE) units with donor group and acceptor group conjugated to each other is synthesized through Wittig reaction. The 1H NMR measurements indicate that the cis-vinylene units exit in polymer backbone. The UV-absorption and Fluorescent emission are investigated.

Abstract: In order to investigate the corrosion performance of reinforced concrete in the marine environment, the seawater hot rain testing (SHRT) equipment was used to imitate the marine environment and accelerate corrosion rate by circularly spraying seawater to the samples under high temperatures which can attain 70°C. The test results show that SHRT can accelerate the chloride ion permeability which can quickly investigate the corrosion performance of reinforced concrete. Different types of material admixtures have different influences on the corrosion performance of reinforcement concrete, and rust inhibitor and cementitious capillary crystalline material can improve the anti-rust resistance of reinforced concrete effectively.

Abstract: The influence of the stress type, stress size and polymer chain number on the thermal performance of the molecular linker was investigated by the nonequilibrium molecular dynamics method (NEMD). The results demonstrate that the thermal conductivity of molecular linker first increases and then decreases with an increment in tension because of the interaction between the phonon mean free path and spectrum red-shifted of the molecular linker. While the molecular linker is in compression, the thermal conductivity is linear relationship with the magnitude of the force. With the length compressed to 90%, the thermal conductivity can be decreased 70% maximally. Moreover, increasing the polymer chain number can improve effectively the thermal performance and the anti-deformation ability of the molecular linker.

Abstract: Regulation of daily physiological functions with approximate a 24-hour periodicity, or circadian rhythms, is a characteristic of eukaryotes. So far, cyanobacteria are only known prokaryotes reported to possess circadian rhythmicity. The circadian system in cyanobacteria comprises both a post-translational oscillator (PTO) and a transcriptional/translational feedback loop (TTFL). The PTO can be reconstituted in vitro with three purified proteins (KaiA, KaiB, and KaiC) with the existence of ATP. Phase of the nanoclockwork has been associated with the phosphorylation states of KaiC, with KaiA promoting the phosphorylation of KaiC, and KaiB de-phosphorylating KaiC. Here we studied the sequence variation of 65 KaiC proteins in evolution, and determined some key residues in KaiC by analyzing the site variation rates of the protein sequences. These key residues could be used to study the key interactions of KaiC with KaiA and KaiB.

Abstract: Experiments were conducted to determine if vacuum cooling has an effect on the physical and chemical quality characteristics of mushroom after cooling and storage. Pressure, temperature and mass variations of mushroom were obtained during vacuum cooling. The pressure was decreased from 10000 Pa to 600 Pa within 4 min and then maintained it until the end of vacuum cooling process. Accordingly the temperature of mushroom dropped from initial 25.1 °C to 2.4 °C within 25 min, and the mass loss was 5.3%. Subsequently, vacuum cooled mushroom were stored at 1±0.5°C. and 85-95% of relative humidity for 2 weeks. The effects of vacuum cooling on the color, firmness, polyphenol oxidase and membrane permeability of mushroom after cooling and storage were determined. The results showed that vacuum cooling significantly reduced the polyphenol oxidase and membrane permeability.

Abstract: Pristine and fluorinated multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were characterized using energy dispersive X-ray spectra (EDX) and X-ray photoelectron spectroscopy (XPS), respectively. The fluorine percentages of fluorinated multi-walled carbon nanotubes (F-MWCNTs) and fluorinated single-walled carbon nanotubes (F-SWCNTs) were 10.42% and 9.67% respectively by EDX. The absorption and de-absorption of fluorine properties were studied using high resolution C 1s and F 1s core level XPS and valence band spectra. The fluorine can be completely dissociated from F-MWCNTs, but partially dissociated from SWCNTs. There was 5.79% fluorine in atomic percent remaining associated with the F-SWCNTs when annealing the nanotubes to 500 °C measured by EDX. The results of F 1s core level XPS indicated that the binding energy of fluorine associated on SWCNTs was shifted from 687.0 eV to 688.3 eV after annealing the nanotubes to 500 °C. The results of valence band spectra showed that the binding energy of F 2p and F 2s shifted from 7.5 eV and 31.0 eV to 8.8 eV and 32.5 eV respectively in SWCNTS. However, the two peaks disappeared in annealed MWCNTs.

Abstract: The synthesis and performance of a molecularly imprinted polymer (MIP) designed to enable the clean-up of the interferences existing in alprazolam (Alpra) drug samples is described. The MIP was synthesized using non-covalent molecularly imprinted method. Nimetazepam (Nimet), which has a similar chemical structure as the major impurities in Alpra drug samples, was used as the dummy template. Methacrylic acid was used as the monomer. Both the affinity and selectivity of the MIP for Nimet and structurally related compounds were examined through batch-rebinding studies. The specific binding amount of Nimet was determined to be 11.4 mg•g-1. The MIP was used as the sorbent in solid phase extraction (MI-SPE) and methanol was used as the washing solvent for the clean-up of Nimet in the Alpra complex samples. The effective clean-up of Nimet was achieved, with a recovery > 90% for Alpra, in the stimulated samples.

Abstract: We developed a supercritical CO₂ extraction procession and determinated ginger essential oil contents from the ginger oleoresin to explore the effects of temperatures or pressures on the supercritical CO₂ extraction. Our research indicated that pressures had little effect on the liquid CO₂ extraction capacity. However, supercritical CO₂ extraction capacity was affected dramatically by the variant pressures. Additionally, changing pressures or temperature pushed the CO₂ into transcritical isolation state. Under this circumstance, we not only ensured the yield of ginger oleoresin, but also did we obtain the ginger essential oil and gingerol simultaneously.

Abstract: We developed a new procession of extraction efficiency of ginger oleoresin by comparing the CO2 flux in liquid state with that in supercritical state under variant pressure conditions. In our this report, we found that the optimal parameters of this procession: 9～10MPa in extraction pressure, 10～20°C in extraction temperature, 8～10MPa in isolation pressure, and 35～45°C in isolation temperature. This procession is steady and ensures both the extraction yield of ginger oleoresin and the low cost of operation.