Qing Guo Tang

Research Progress on Thermal Insulation Materials

Research progress of thermal insulation materials was briefly reviewed and discussed based on the classification of obstructive insulation, reflective insulation, and radiative insulation materials. Research orientations related to thermal insulation materials were also proposed.

Thermal Insulation Coatings Containing Sepiolite Mineral Fibers and their Performance

In this text, the effective thermal conductivity of different shape filler particles was investigated. The thermal insulation coatings were prepared using hollow glass beads and sepiolite as thermal insulation fillers and the thermal insulation effect was evaluated. The results show that the optimum ratio of sepiolite and hollow glass beads is 6:1, and the temperature difference of upper box and lower box is up to 18 °C. The main reason for this phenomenon is that the thermal conduction chain is difficult to form in the direction of heat flow, thus leading to the increase of thermal resistance and decrease of thermal conductivity.

Preparation and Properties of Thermal Insulation Latex Paint for Exterior Wall Based on Defibred Sepiolite and Hollow Glass Microspheres

Thermal insulating latex paint for exterior wall was prepared by water as dispersing media, polyacrylic emulsion as basic material, defibered sepiolite and hollow glass microspheres as main functional additives. The thermal insulation effect and mechanism were studied by thermal insulation effect testing device and visible light reflectance tester. The results show that the optimum contents of functional additives are as follows: 8% defibred sepiolite fibers, 6% hollow glass microspheres. The coating could arrest heat transmission and reflect visible light effectively.

Research Progress on Resource Utilization of Iron Tailings and its Development Trend in China

The treatment of iron tailings has been a global issue, which has bought serious impact on the environment, it was considered to be a potential threat to human lives. In the present paper, the development situation of iron tailings utilization in China is investigated, the problems existed is analyzed and suggestions are provided, which are hoped to be valuable in the future research and the development of functional materials and products. Keywords: Iron tailings, resource utilization, functional materials, environment protection

Effect of Attapulgite Modification on Properties of Polypropylene Nanocomposites

Polypropylene nanocomposites were prepared by means of melt mixing using attapulgite as inorganic components. The relation between surface free energy and mechanical properties of polypropylene nanocomposites and elasticized mechanism analysis of modified attapulgite nanofibers were mainly studied. The results showed that the modulus, fracture strength, fracture extensibility, tensile strength, yield strength, bend strength, flexural modulus and dynamic ductility properties of nanocomposites all enhanced obviously after modified attapulgite nanofibers were filled up. Surface free energy of attapulgite nanofibers and impact toughness properties of nanocomposites were in approximate inversely-proportion quadratic function relationship, which could provide a new way of thinking in the field of nanocomposites research.

Effect of Sepiolite Nanofibers on Properties of EPDM Nanocomposites

In order to use sepiolite nanofibers as rubber fillers, the hydrophilic character of sepiolite nanofibers should be modified by grafting organic group and controlling surface energy and proportion of dispersive interaction for improving compatibility of sepiolite nanofibers in rubber matrix. The surface energies of sepiolite nanofibers were measured by several liquids which were different on surface energy and polar interaction and calculated by Wus equation. The results showed that the mechanical properties can be improved after reinforcement by modified sepiolite nanofibers.

Preparation and Characterization of Sepiolite Nanofibers by Microwave Chemical Methods

The sepiolite samples were defibered by using microwave chemical technique, and then different sepiolite samples were obtained with different treatment process. The effect of reaction time on the defibering for sepiolite fiber bundles was studied systematically. Through characterization by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), it was found that the defibered sepiolite samples had an average diameter of about 100 nm and length greater than 20μm. The defibering effect of sepiolite samples as prepared reached optimum at the reaction time of 13 min, and the structural stability of sepiolite was kept after defibering treatment.

Effect of Surface Active Agent on Defibering for Sepiolite Fiber Bundles

The cationic surfactant-octadecyl trimethyl ammonium chloride was added to the mixture of sepiolite powders and water with mechanical stirring. The effect of cationic surfactant on the defibering of fiber bundles was studied. The samples were characterized by X-Ray diffraction (XRD), bulk density, scanning electron microscope (SEM), FT-IR spectrum (FTIR) and thermal conductivity. The results indicated that the surface active agent could protect the structure of sepiolite fibers effectively, the bulk density and the thermal conductivity of the fibers could reach 0.06g/cm3 and 0.042W/(m.K), respectively.

Advances in Water Treatment Application of Sepiolite Mineral Materials

Synthetic nanomaterials have the disadvantages of large-scale investment, high energy consumption, complex production process and heavy environmental load. Mineral nanomaterials such as sepiolite group mineral nanomaterials are characterized by small size effect, quantum size effect and surface effect. Water treatment application of sepiolite group mineral nanomaterials has become an active research area and showed good development and application prospects. Based on the above reasons, this paper systematically summarizes the water treatment application of sepiolite group mineral nanomaterials, and development trend related to water treatment application of sepiolite group mineral nanomaterials were also proposed.

Zeta Potential of Sepiolite in Aqueous System

Zeta potential of purified sepiolite in aqueous system was studied as a function of pH and solid content. From the experimental results, it was found that sepiolite surface acquired a negative charge in water at natural pH, and the value of zeta potential decreased with the increase of pH value. Solid content had effect on zeta potential, but it can be minimized by the increase of time.