• Energy Research

The capillary effect has wide applications from biology and textile engineering to nanotechnology especially the micro-electromechanical systems and microfluidics device. The capillary vibration significantly affects its mass transmission. This paper establishes a nonlinear oscillator of a deforming capillary tube. The geometric potential theory is used to estimate the capillary force. The paper reveals that the low-frequency property of capillary vibration plays an important role not only in life but also engineering applications.

Wool fiber has a complex hierarchic inner structure. However, like most of the natural things, wool fiber does not have an exactly strict self-similar fractal feature. Here, we calculate the fractal dimension of each hierarchic level of wool fiber using the two-scale dimension method. The obtained fractal dimension of wool fiber in different hierarchic level ranges between 1.37 and 1.47, which is close to that obtained according to the traditional fractal geometry. Thermal property of wool fiber is investigated based on the fractal feature of wool fiber. The result shows that the temperature gradient and the rate of the temperature gradient along the fiber is very slow, suggesting that wool fiber has a good thermal retention property.

Background: Wastewater involving a lot of contaminants like organic dyes from the textile finishing industry causes a greater adverse impact on human beings. There are many patents on nanofibers involved metallic oxides, this paper studies photocatalytic degradation of free-pollution Zinc Oxide (ZnO) nanomaterials on dye decontamination. Objective: Polyacrylonitrile (PAN) nanofibrous membranes loaded with Zinc Oxide (ZnO) nanowires were fabricated and evaluated for photocatalytic degradation. Methods: In this work, Polyacrylonitrile (PAN) nanofibrous membranes loaded with ZnO seeds were prepared by electrospinning PAN/Zn (Ac)2 solution followed by a thermal decomposition process. ZnO nanowires were hydrothermally grown on the surface of PAN nanofibers. The effects of the ratio of PAN and zinc acetate in a solution, decomposition temperature and ammonia (NH4OH) on the morphologies of ZnO nanowires were observed. ZnO nanowires showed the optimum morphologies when the ratio of PAN/Zn (Ac)2 was 10:1.5. The decomposition temperature was 150oC, and NH4OH was added in the hydrothermal reaction. The photocatalytic degradation of Rhodamine B solution under UV irradiation was used as a model reaction. The photodegradation ability of the ZnO @PAN membrane doped with cerium (Sm) was also investigated. Results: Slight Sm doping increased the photocatalytic degradation rate from 57% to 89% under ultraviolet light irradiation for 2h. After 5 times of cycling under the same conditions, it still maintained the dye decolorization rate that was above 65%. Conclusion: Sm doped ZnO nanowires @PAN nanofibrous membranes were easily produced and could provide a novel process for the degradation of dye decontamination.