Mechanism of PVC’s Solid-Phase Photocatalytic Degradation Enhanced by Plasma

2007 ◽  
Vol 544-545 ◽  
pp. 155-158
Author(s):  
Xiao Jing Li ◽  
Guan Jun Qiao ◽  
Jie Rong Chen

The solid-phase photocatalytic degradation of poly (vinyl chloride) (PVC) films was investigated in ambient air. The photodegradation of the PVC and PVC-TiO2 was compared with that of plasma-treated PVC and plasma-treated PVC-TiO2 performing a weight loss monitoring and scanning electron microscopic (SEM) analysis. The SEM of the PVC-TiO2 film treated by plasma showed many cracks on the surface after photodegradation. Furthermore, the surface wettability and surface structure of PVC after nitrogen plasma treatment was characterized by contact angle, surface tension, and electron spin resonance (ESR). The experiment indicated that the surface free energy and wettability of PVC treated by plasma increased greatly. ESR revealed that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after treatment. The free radicals on the surface of plasma-treated PVC possibly decreased the activating energy of photocatalytic reaction, which belongs to the free radicals reaction, because the chemical activity of the free radicals was high. According to these findings, a mechanism on the photodegradation of plasma-treated PVC-TiO2 is proposed.

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Wasim Asghar ◽  
Ishtiaq A. Qazi ◽  
Hassan Ilyas ◽  
Aftab Ahmad Khan ◽  
M. Ali Awan ◽  
...  

Comparative photocatalytic degradation of polythene films was investigated with undoped and metal (Fe, Ag, and Fe/Ag mix) doped TiO2nanoparticles under three different conditions such as UV radiation, artificial light, and darkness. Prepared photocatalysts were characterized by XRD, SEM, and EDS techniques. Photocatalytic degradation of the polythene films was determined by monitoring their weight reduction, SEM analysis, and FTIR spectroscopy. Weight of PE films steadily decreased and led to maximum of 14.34% reduction under UV irradiation with Fe/Ag mix doped TiO2nanoparticles and maximum of 14.28% reduction under artificial light with Ag doped TiO2nanoparticles in 300 hrs. No weight reduction was observed under darkness. Results reveal that polythene-TiO2compositing with metal doping has the potential to degrade the polythene waste under irradiation without any pollution.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Adam W. Jarrell ◽  
Brayden C. Terry ◽  
Alvin M. Strauss ◽  
George E. Cook

Abstract Friction stir extrusion is a derivative process of friction stir welding for joining dissimilar materials. The process forms a mechanical joint through extrusion to form interlocking features between two metals. When joining AA6061-T6 to mild steel through extrusion of a dovetail, much of the T6 heat treatment of the aluminum in and around the weld is lost during the process. This paper details the examination of a post-processing aging process to return AA6061 to the T6 condition. Through a 10-h precipitation hardening process at 170 °C. The welds experienced a 23.9% increase in the tensile strength from 2193 N as-welded to 2718 N after 10 h. Hardness measurements showed a return close to T6 conditions in both the weld nugget and extruded material, 67.5–83.5 HRF and 54.7–81.8 HRF, respectively, during the heat treatment period. The steel showed no substantial changes in hardness during the heat treatment. Scanning electron microscopic (SEM) analysis revealed significant changes in the sizes of two species of inclusions within the aluminum during both the welding and post-processing.


2014 ◽  
Vol 79 (8) ◽  
pp. 993-1005 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Konstantin Popov ◽  
Evica Ivanovic ◽  
Goran Brankovic

The processes of Pb electrodeposition in the diffusion control were examined by the scanning electron microscopic (SEM) analysis of the formed crystals. Orientation of grains of hexagonal shape formed in the initial stage of electrodeposition strongly affected the final morphology of Pb crystals. Formation of Pb crystals of the different shape from the same initial shape was discussed by the effect of orientation of initially formed grains on the type of diffusion control. The spherical diffusion layer was formed around the tip of the hexagonal shaped grain oriented by the tip towards the bulk of solution leading to formation of elongated crystals in the growth process. On the other hand, the cylindrical type of diffusion was responsible for growth of hexagonal shaped grains oriented by the lateral side towards the bulk of solution. Pb crystals with well defined sides parallel to the surface area of macroelectrode were formed by this type of diffusion.


2018 ◽  
Vol 15 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Rakesh B Kabariya ◽  
Vimal M Ramani

The emerging concept of thread-based microfluidics has shown great promise for application to inexpensive disease detection and environmental monitoring. This paper describe the properties of thread for the development of thread based low-cost microfluidics device for the diagnostic, food safety and environmental assay. Various properties of thread like capillary flow, wicking capacity and absorption capacity, make them important to fabricate the low-cost microfluidics device. In this paper, three different thread sample viz. cotton yarn, cotton thread and spun thread were taken and different properties like wicking capacity, fluid capillary flow, absorption capacity were measured as well as Scanning Electron Microscopic (SEM) analysis of the same was also carried out to study the morphology and texture of thread fibers. Data obtained from result indicate that the cotton thread having all the ideal characteristic to fabricate the diagnostic device and thus it is suitable for the fabrication of thread based microfluidics device for the diagnostic purpose.


2021 ◽  
pp. 2150073
Author(s):  
RASHED MUSTAFA MAZARBHUIYA ◽  
BHARGAB MADHAB BARUA ◽  
MANESWAR RAHANG

This paper presents the surface modification of aluminium-6061 by electric discharge machining (EDM). Si–Cu powder metallurgical green compact tool is used to deposit its material on to the work surface under reverse polarity of EDM. Compact load, current and pulse on-time are selected control parameters. Material deposition rate (MDR), tool wear rate (TWR) and surface roughness ([Formula: see text] are considered as process outputs. Scanning electron microscopic (SEM) analysis and energy dispersive X-ray (EDX) analysis show the presence of tool materials in the deposit of work surface. Olympus optical micrograph shows an average thickness of the deposited layer to be 18.73[Formula: see text][Formula: see text]m. The hardness of the deposited layer is found to be 268[Formula: see text]HV. Analysis of variance (ANOVA) shows the compact load to be the most effective parameter on surface modification followed by pulse on-time and current, respectively.


2019 ◽  
Vol 17 (43) ◽  
pp. 122-127
Author(s):  
Mustafa A. Mustafa

In this work the fabrication and characterization of poly(3-hexylthiophene) P3HT-metallic nanoparticles (Ag, Al). Pulsed Laser Ablation (PLA) technique was used to synthesis the nanoparticles in liquid. The Fourier Transformer Infrared (FTIR) for all samples indicate the chemical interaction between the polymer and the nanoparticles. Scanning Electron Microscopic (SEM) analysis showed the particle size for P3HT-AgNps samples between 44.50 nanometers as well the spherical structure. While for P3HT-AlNps samples was flakes shape. Energy Dispersive X-ray (EDX) spectra show the existing of amount of metallic nanoparticles.


2010 ◽  
Vol 35 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Bhoomika Ahuja ◽  
Ramakrishna Yeluri ◽  
M Sudhindra Baliga ◽  
AK Munshi

Objectives: This study was undertaken to evaluate the topographical features of enamel surface deproteinized with sodium hypochlorite (NaOCl) and etched with phosphoric acid (H3PO4) compared to phosphoric acid alone using Scanning Electron Microscopic (SEM) Analysis. Study Design: 30 enamel blocks of 1mm2 from ten human sound extracted permanent molars were obtained and treated as under: Group 1 (10 blocks): Enamel surface was etched with 37% H3PO4 gel for 15 seconds. Group 2 (10 blocks):Enamel surface was treated with 5.25% NaOCl for 60 seconds and then etched with 37% H3PO4 gel for 15 seconds. 10 enamel blocks were included in the control group where no treatment was carried out. The samples were subjected to SEM analysis and 5 microphotographs of each sample were obtained at 500X magnification and evaluated for the quality of etching pattern of the enamel in percentage (%) using Auto-CAD 2007 software. Results: Mean values of etching pattern in Group 1 being 55.76% and Group 2 being 53.58%. No significant difference was observed between the two groups. Conclusion: The use of 37% phosphoric acid for 15 seconds still remains the best method for pretreatment of enamel.


2016 ◽  
Vol 697 ◽  
pp. 243-247 ◽  
Author(s):  
Ai Mei Yang ◽  
Jian Ming Deng ◽  
Cong Xue Su ◽  
Wen Hao Jia ◽  
Lai Jun Liu

The barium titanium based PTC ceramic with two kind of colors, light blue and yellow, were obtained by changing sintering processing. In order to reveal the relationship between color and electrical properties of the ceramics. The phase structure and microstructure of as synthesized samples were investigated by powder X-ray diffraction (XRD) and scanning electron microscopic (SEM) analysis. The micro area elements were characterized by electron probe micro-analyzer (EPMA) and x-ray photoelectron spectrometer (XPS). The thermo-sensitive properties were studied by resistance-temperature measurement system. The results reveal that two kinds of PTC ceramics have the same structure, similar elements, but different microstructure and valence concentration of titanium. It is suggested that difference of color of the PTC ceramics are originated from the defect concentration of titanium.


2020 ◽  
Vol 85 (6) ◽  
pp. 795-807
Author(s):  
Fatemeh Shafiei ◽  
Kourosh Jafarzadeh ◽  
Ali Madram

The morphologies of the copper deposits obtained by pulsating overpotential regime with prolonged pulse and pause durations from the solution of 0.15 M CuSO4 in 0.50 M H2SO4 at overpotentials lower, higher and belonging to the plateau of limiting diffusion current density were compared with those obtained by the same electrodeposition regime from solutions of 0.075 and 0.30 M CuSO4 in 0.50 M H2SO4 and 0.15 M CuSO4 in 0.25 and 1.00 M H2SO4 at overpotentials outside the plateau of limiting diffusion current density. These samples were characterized by scanning electron microscopic (SEM) analysis and the cathodic polarization characteristics from solutions compared. Increasing the Cu(II) concentration led to an increase in the limiting diffusion current density. Decreasing the H2SO4 concentration shifts both beginning and the end of the plateau of the limiting diffusion current density towards higher electrodeposition overpotentials. Also, electrodeposition in solutions of 0.15 M CuSO4 in 0.25 and 1.00 M H2SO4 led to the formation of morphological forms of copper deposits characteristic for electrodeposition of copper from higher CuSO4 or lower H2SO4 in solution at some higher overpotentials.


74 unconfined compressive strength tests (UCS) were conducted to examine effect of the Sugarcane Bagasse ash (SCBA) on compressive behavior of clay stabilized with cement, mixed with various cane ash contents, when uncovered to magnesium sulphate (MgSO4 ). The analysis showed an enhancement in the range of 10% to 35% for control specimens and an enhancement of 60% to 180% for magnesium sulfate exposed specimens. Scanning electron microscopic (SEM) analysis also showed interaction of clay and cement particles with sulphate confirming the results in the laboratory.


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