Shi Biao Zhou

The Preparation and Performance of Gypsum-Based Composites

Gypsum-based composites was produced using gypsum power(cement), PVA, white latex and sawdust via pouring process. The influences of water/ cement ratio, PVA/ cement ratio and glue/ cement ratio on release time, density and impact strength of the gypsum-based composites were investigated through orthogonal experiment. The results showed that PVA strengthened obviously impact strength, and also delayed the s release time of the Gypsum-based composites. Sawdust as light filler reduced the composites density. Low content of white latex is beneficial to increase the impact strength, while high content of white latex is easy to form micelle in the gypsum crystallization process and is enclosed in crystals, which decreases the impact strength of composite materials.

Mechanical Properties of Elastomeric Terpolymer Nanocomposites Containing Nano-SiO2

Nanocomposites were obtained by mixing elastomeric terpolymer and nano-SiO2 in double-screw extruder at 130-150 °C, in which elastomeric terpolymer was prepared by terpolymerization of poly(methyl methacrylate (PMMA) macromonomer, butyl acrylate(BA), and acrylic acid(AA) in benzene using azobisisobutyronitrile (AIBN) as initiator. The results indicated that increasing the amount of PMMA, the molecular weight of PMMA and terpolymers as well as the content of carboxylic acid were favorable to increase the mechanical properties of nanocomposites. In addition, the tensile strength and the modulus at 300% elongation of nanocomposites reach to a maximum while the mass ratio of nano-SiO2 to terpolymer is 3%.

Synthesis and Electrochemical Performance of K-Doped Li4Ti5O12 as Anode Material for Lithium-Ion Batteries

Spinel Li4-xKxTi5O12 (x=0, 0.03) were successfully synthesized by a traditional solid-state method and systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the charge-discharge test, respectively. The results demonstrated that Li3.97K0.03Ti5O12 exhibited much better rate performance in comparsion with Li4Ti5O12. At 0.2 C and 10 C, it delivered a discharge capacity of 173 mAh g-1 and 124 mAh g-1 respectively, and after 100 cycles at 10 C, 96.1% of its initial capacity was retained.

Physical and Electrochemical Properties of Li2-xFeSiO4/C Cathode Material for Li-Ion Batteries

Li2-xFeSiO4/C (x=0.01, 0.05, 0.1) were successfully synthesized by a traditional solid-state method and systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the charge-discharge test, respectively. The results demonstrated that Li2-xFeSiO4 exhibited the best electrochemical performance among the three as-synthsied samples. it delivered a specific discharge capacity of 142 mAh g-1, 112 mAh g-1 at 0.2 C and 2 C, respectively. After 100 cycles at the rate of 1 C, the discharge capacity remained 95.1% of its initial value.

Molecular Beacon-Based Fluorescent Biosensor for Sensitive Detection of Single Nucleotide Polymorphism

A sensitive fluorescent biosensing strategy based on structure-switching of molecular beacon for the detection of single nucleotide polymorphism is proposed in this study. In the absence of target DNA, only low background fluorescence can be detected since the formation of hairpin structure induces close proximity of fluorophore and quencher. On the contrary, the fluorescence intensity increases significantly after introduction of target DNA because structure-switching of molecular beacon results in separation of fluorophore and quencher. The change of fluorescence intensity is linear with concentration of target DNA, and a molecular beacon-based sensing system for fluorescent detection of single nucleotide polymorphism is fabricated. The target DNA can be sensitively detected in a linear dynamic range from 17.58nM-1.125μM with a low detection limit of 8 nM. Moreover, good reproducibility and high specificity are achieved.

Reusable Electrochemical Biosensor for Sensitive Detection of Single Nucleotide Polymorphisms Based on Gold Nanoparticle Self-Assembly

A reusable electrochemical biosensing strategy based on gold nanoparticle involved layer-by-layer self-assembly for sensitive detection of single nucleotide polymorphisms is proposed in this study. Making use of the strong sulfur-Au affinity, ethanthiol and capture probe modified gold nanoparticles are self-assembled onto the surface of gold electrode successively. The target DNA hybridizes with the capture probe and ferrocene labeled signaling probe successively via sandwich hybridization reaction. By measuring ac current voltammetry, the target DNA can be sensitively detected in a linear dynamic range from 4.1-410 nM with a low detection limit of 2 nM. Making use of self-assembled gold nanoparticles layer, a large amount of capture probes can be modified onto the gold electrode, supporting the high sensitivity of the proposed strategy. In addition, good reproducibility, high selectivity and stability are achieved. In particular, the biosensor can be easily regenerated by melting in hot water, making it reusable.

The Conductive of Composites Made from Polypyrrole and PBA-g-PMMA-GMA

A novel PPy/PBA-g-PMMA-GMA (copolymer) composites were prepared and the preparation conditions, characterization and properties of the composites were investigated. The results indicate that the oxidant types, molar ratio of oxidant/monomer, polymerization time, PPy content affect greatly the conductivity of the PPy/terpolymer composites. The ultimate elongation of composites decreases with increasing PPy content,while high PPMM content brings forth high tensile strength.

Study on Conductive Polypyrrole/P(Ba-co-Aa)-g-PMMA-GMA Composites

A novel PPy/P(BA-co-AA)-g-PMMA-GMA (terpolymer) composites were prepared and the preparation conditions, characterization and properties of the composites were investigated. The results indicate that the oxidant types, molar ratio of oxidant/monomer, polymerization time, PPy content affect greatly the conductivity of the PPy/terpolymer composites. The ultimate elongation of composites decreases with increasing PPy content,while high PPMM content brings forth high tensile strength.

Reusable Electrochemical Aptasensor for Sensitive Detection of Small Molecules Based on Structure-Switching Hairpin Probe

A reusable electrochemical biosensing strategy based on structure-switching hairpin probe for the detection of small molecules is proposed using cocaine as the model analyte. Aptamer probe hybridized with the immobilized signal probe to form DNA duplex. When target small molecule was added, competition between target molecule and the signal probe with the aptamer probe happened, which induced the signal probe from stretched duplex to hairpin structure. By measuring ac current voltammetry, the target molecule can be sensitively detected in a linear dynamic range from 1 nM-1000 nM with a low detection limit of 0.7 nM. In particular, the biosensor can be easily regenerated by melting in hot water, making it reusable.

Study the Influences of ZnEt2 on Ethylene Chain Transfer Polymerization

The influences of ZnEt2 on ethylene chain transfer polymerization were investigated in detail and the polymerization mechanism was thoroughly analyzed. The results indicated that ZnEt2 contributed greatly to increase the activity of α-diimine nickel complex/ZnEt2/MAO(MAO: methylaluminoxane). It was striking that α-diimine nickel complex/ZnEt2 catalyst system (1/100 mol/mol) exhibited 8.0 ×104g/mol∙h activity, it was possible the formation of the ion pairs of Nickel and Zinc was convenient for ethylene chain propagation, however, the ion pairs were unstable in ethylene polymerization.