Pub Date : 2019-06-25DOI: 10.18311/JSST/2019/20103
Manuel George, A. Mohanty
The paper discusses about the wear and micro hardness behavior of Graphene Decorated with Graphene Quantum Dots (G-D-GQD) reinforced epoxy composites. The samples were prepared by open mold casting method by adding 0.25–1 wt. % (in an interval of 0.25%) of GDGQD and evaluated on a reciprocating wear tester configuration for wear and coefficient of friction properties. The micro-hardness testing of the G-D-GQD particles embedded epoxy composites has been performed and the hardness value results were compared with neat epoxy to find the improvement in hardness. Significant improvements in the hardness and wear resistance of the epoxy nanocomposites was obtained by the embedding of G-DGQD fillers, which is due to the efficient bonding of GDGQD filler with the epoxy matrix. Scanning Electron Microscope (SEM) images of the worn composites were analysed to get an insight into the morphology of the surfaces. Furthermore, the coefficient of friction of the composites got increased with the wt. % of fillers in the base material, but due to the superior bond strength and lesser agglomeration of the particles, the Vicker's hardness improved and the wear loss reduced. Hence the surface area coverage of G-D-GQDs got a significant role in the reduced wear loss and thereby coming to a threshold value. The study concludes by suggesting that 0.25 wt. % GDGQD/epoxy composites shown a least wear rate and increased hardness of 0.023% and 26%, respectively thereby suggesting application involving reduced wear rates.
{"title":"Wear and Hardness Studies of Graphene Decorated with Graphene Quantum Dots (G-D-GQD) Embedded Epoxy Nano Composites","authors":"Manuel George, A. Mohanty","doi":"10.18311/JSST/2019/20103","DOIUrl":"https://doi.org/10.18311/JSST/2019/20103","url":null,"abstract":"The paper discusses about the wear and micro hardness behavior of Graphene Decorated with Graphene Quantum Dots (G-D-GQD) reinforced epoxy composites. The samples were prepared by open mold casting method by adding 0.25–1 wt. % (in an interval of 0.25%) of GDGQD and evaluated on a reciprocating wear tester configuration for wear and coefficient of friction properties. The micro-hardness testing of the G-D-GQD particles embedded epoxy composites has been performed and the hardness value results were compared with neat epoxy to find the improvement in hardness. Significant improvements in the hardness and wear resistance of the epoxy nanocomposites was obtained by the embedding of G-DGQD fillers, which is due to the efficient bonding of GDGQD filler with the epoxy matrix. Scanning Electron Microscope (SEM) images of the worn composites were analysed to get an insight into the morphology of the surfaces. Furthermore, the coefficient of friction of the composites got increased with the wt. % of fillers in the base material, but due to the superior bond strength and lesser agglomeration of the particles, the Vicker's hardness improved and the wear loss reduced. Hence the surface area coverage of G-D-GQDs got a significant role in the reduced wear loss and thereby coming to a threshold value. The study concludes by suggesting that 0.25 wt. % GDGQD/epoxy composites shown a least wear rate and increased hardness of 0.023% and 26%, respectively thereby suggesting application involving reduced wear rates.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43639101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-25DOI: 10.18311/JSST/2019/22173
J. Sharma, B. S. Sidhu, Rajesh Gupta
The duplex treatment combining the salt bath nitrocarburizing with post-oxidation technique provides an excellent technique for achieving improved hardness, wear and corrosion resistance of the surface of various steels. Arcor® is a merger of Sursulf and a post-oxidation process (Oxynit). In the present research effects of the duplex treatment (nitrocarburizing and post-oxidation) on the surface morphology of AISI 1018 low carbon steel are reported. Observations revealed that by increasing the holding time a considerable improvement in mechanical properties occured. Optical microscopy investigations revealed compound and diffusion zones on the steel surface with approx. 24 μm thick compounds and oxide layer. Furthermore, a significant decrease in specific wear rate has been observed due to the compact and uniform compound layer.
{"title":"Surface Modification of AISI 1018 Low Carbon Steel by Duplex Treatment of Nitrocarburizing and Post-Oxidation","authors":"J. Sharma, B. S. Sidhu, Rajesh Gupta","doi":"10.18311/JSST/2019/22173","DOIUrl":"https://doi.org/10.18311/JSST/2019/22173","url":null,"abstract":"The duplex treatment combining the salt bath nitrocarburizing with post-oxidation technique provides an excellent technique for achieving improved hardness, wear and corrosion resistance of the surface of various steels. Arcor® is a merger of Sursulf and a post-oxidation process (Oxynit). In the present research effects of the duplex treatment (nitrocarburizing and post-oxidation) on the surface morphology of AISI 1018 low carbon steel are reported. Observations revealed that by increasing the holding time a considerable improvement in mechanical properties occured. Optical microscopy investigations revealed compound and diffusion zones on the steel surface with approx. 24 μm thick compounds and oxide layer. Furthermore, a significant decrease in specific wear rate has been observed due to the compact and uniform compound layer.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46629320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-25DOI: 10.18311/JSST/2019/18461
K. Srinivasarao, C. Prameela
Thin films of (MoO3)x-(WO3)1-x (x = 0.4, 0.6, 0.8) were deposited on glass and silicon (100) substrates by flash evaporation technique. The purpose of the flash evaporation is to prevent the decomposition of composite into individual species during thin film deposition. The films were deposited at the oxygen partial pressures of 2x10-5, 2x10-4 mbar and substrate temperatures of 150 0C, 350 0C. The deposited films were characterized for their structure by Graging Incidence X-ray Diffraction (GIXRD), microstructure by Field Emission Scanning Electron Microscopy (FESEM), optical property by UVVis spectra. The X-ray diffraction reveals that the (MoO3)x-(WO3)1-x composite thin film crystallizes in orthorhombic and monoclinic phases. At lower oxygen partial pressures of 2x10-5 mbar and lower substrate temperatures of 150 0C the film crystallizes in orthorhombic and tetragonal phases. Whereas at higher substrate temperatures of 350 0C both orthorhombic and monoclinic mixed phases are present. The optical transmittance spectra of the films were recorded in the wavelength range 300-1100 nm. The optical energy gap of the films is 3.05 eV and increases to 3.21 eV with increase in MoO3 concentration. The width of localized states is 0.47 eV and decreasing with increasing MoO3 concentration. The oxide materials in thin film form exhibit the change in the transmittance when exposed to electro magnetic waves (EM) of visible region. In this respect the estimation of color centre concentration will give the information regarding the response of the films to change their transmittance when exposed to EM waves in the visible region. The colourcenter concentration of the films (for x = 0.4) deposited at 150 0C and irradiation time of 120 minutes, is 3.02 x 1017/cm3 and reaches to maximum value of 4.94 x 1017/cm3, (for x = 0.8) when deposited at 350 0C and irradiated for 150 minutes.
采用闪速蒸发技术在玻璃和硅（100）衬底上沉积了（MoO3）x-（WO3）1-x（x=0.4，0.6，0.8）薄膜。闪蒸的目的是防止复合材料在薄膜沉积过程中分解成单个物种。薄膜在氧分压为2x10-5、2x10-4毫巴和衬底温度为150℃、350℃的条件下沉积。用Graging Injection X-ray Diffraction（GIXRD）表征了沉积薄膜的结构，用场发射扫描电子显微镜（FESEM）表征了薄膜的微观结构，用UVVis光谱对薄膜的光学性能进行了表征。X射线衍射表明，（MoO3）X-（WO3）1-X复合薄膜结晶为正交相和单斜相。在2x10-5毫巴的较低氧分压和150℃的较低衬底温度下，薄膜结晶为正交相和四方相。而在350℃的较高衬底温度下，存在正交和单斜混合相。记录了薄膜在300-1100nm波长范围内的透光光谱。薄膜的光学能隙为3.05eV，并且随着MoO3浓度的增加而增加到3.21eV。局域态的宽度为0.47eV，并且随着MoO3浓度的增加而减小。薄膜形式的氧化物材料在暴露于可见区域的电磁波（EM）时表现出透射率的变化。在这方面，色中心浓度的估计将给出关于当暴露于可见区域中的EM波时膜改变其透射率的响应的信息。在150℃和120分钟的照射时间下沉积的膜（对于x=0.4）的色心浓度为3.02 x 1017/cm3，并且当在350℃沉积并照射150分钟时达到4.94 x 1017/cm2的最大值（对于x=0.8）。
{"title":"Physical Investigations on (MoO3)x-(WO3)1-x Composite Thin Films","authors":"K. Srinivasarao, C. Prameela","doi":"10.18311/JSST/2019/18461","DOIUrl":"https://doi.org/10.18311/JSST/2019/18461","url":null,"abstract":"Thin films of (MoO3)x-(WO3)1-x (x = 0.4, 0.6, 0.8) were deposited on glass and silicon (100) substrates by flash evaporation technique. The purpose of the flash evaporation is to prevent the decomposition of composite into individual species during thin film deposition. The films were deposited at the oxygen partial pressures of 2x10-5, 2x10-4 mbar and substrate temperatures of 150 0C, 350 0C. The deposited films were characterized for their structure by Graging Incidence X-ray Diffraction (GIXRD), microstructure by Field Emission Scanning Electron Microscopy (FESEM), optical property by UVVis spectra. The X-ray diffraction reveals that the (MoO3)x-(WO3)1-x composite thin film crystallizes in orthorhombic and monoclinic phases. At lower oxygen partial pressures of 2x10-5 mbar and lower substrate temperatures of 150 0C the film crystallizes in orthorhombic and tetragonal phases. Whereas at higher substrate temperatures of 350 0C both orthorhombic and monoclinic mixed phases are present. The optical transmittance spectra of the films were recorded in the wavelength range 300-1100 nm. The optical energy gap of the films is 3.05 eV and increases to 3.21 eV with increase in MoO3 concentration. The width of localized states is 0.47 eV and decreasing with increasing MoO3 concentration. The oxide materials in thin film form exhibit the change in the transmittance when exposed to electro magnetic waves (EM) of visible region. In this respect the estimation of color centre concentration will give the information regarding the response of the films to change their transmittance when exposed to EM waves in the visible region. The colourcenter concentration of the films (for x = 0.4) deposited at 150 0C and irradiation time of 120 minutes, is 3.02 x 1017/cm3 and reaches to maximum value of 4.94 x 1017/cm3, (for x = 0.8) when deposited at 350 0C and irradiated for 150 minutes.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44808098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.18311/JSST/2019/20110
S. Sivarajan, R. Padmanabhan, A. Sharma
Wear in machineries and parts are one of the major problems encountered in industrial processes. These problems along with corrosion lead to the development of surface engineering techniques that involves applying surface coatings to components to obtain composite material with tribological properties unattainable by base material alone. In the present paper, DLC and WC coatings are produced on AISI D2 steel by Physical Vapor Deposition (PVD).The samples are characterized with tribological test. The applied load is taken as 25 Newton, and sliding velocity as 0.5 m/s. Samples with DLC coatings display less friction and good hardness.
{"title":"Improvement in the Tribological Properties of AISI D2 Die Steel by DLC and WC-C Coatings","authors":"S. Sivarajan, R. Padmanabhan, A. Sharma","doi":"10.18311/JSST/2019/20110","DOIUrl":"https://doi.org/10.18311/JSST/2019/20110","url":null,"abstract":"Wear in machineries and parts are one of the major problems encountered in industrial processes. These problems along with corrosion lead to the development of surface engineering techniques that involves applying surface coatings to components to obtain composite material with tribological properties unattainable by base material alone. In the present paper, DLC and WC coatings are produced on AISI D2 steel by Physical Vapor Deposition (PVD).The samples are characterized with tribological test. The applied load is taken as 25 Newton, and sliding velocity as 0.5 m/s. Samples with DLC coatings display less friction and good hardness.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42128791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-03DOI: 10.18311/JSST/2018/19839
Hossam Jalal, Yones Saoud, F. Karabet
The choice of suitable aluminum alloys for a particular application involves tensile strength, density, softness, formability, operability, welding ability, corrosion resistance, etc. Aluminum alloys are widely used in aircraft because of the high strength to weight ratio. The anodizing process of AA has been applied industrially to improve corrosion resistance. In this research, various factors such as (concentration of the electrolyte, temperature, and voltage) affect thickness and hardness during anodizing of AA6066 in sulphuric acid. Process factors have been modified using the Taguchi method through the Design of Experiments (DOE). The Taguchi method includes an orthogonal array of factors, a Signal-to-Noise ratio (S/N), Analysis of Variance (ANOVA), which were used to determine the optimum condition levels for aluminum alloy 6066 anodizing, and to analyze the effect of these conditions on thickness and hardness. It was found that the most effective factor on thickness and micro-hardness is the concentration of the electrolyte. Optimization test was carried out by Taguchi optimization test and the optimal conditions were determined. Finally, the anodizing was carried out on aluminum sample under the optimal conditions then scanned by SEM. The thickness and micro hardness obtained at the optimal conditions were 25μm, and 640Hv, respectively.
{"title":"Optimization Condition for Aluminum Alloy 6066 Anodizing","authors":"Hossam Jalal, Yones Saoud, F. Karabet","doi":"10.18311/JSST/2018/19839","DOIUrl":"https://doi.org/10.18311/JSST/2018/19839","url":null,"abstract":"The choice of suitable aluminum alloys for a particular application involves tensile strength, density, softness, formability, operability, welding ability, corrosion resistance, etc. Aluminum alloys are widely used in aircraft because of the high strength to weight ratio. The anodizing process of AA has been applied industrially to improve corrosion resistance. In this research, various factors such as (concentration of the electrolyte, temperature, and voltage) affect thickness and hardness during anodizing of AA6066 in sulphuric acid. Process factors have been modified using the Taguchi method through the Design of Experiments (DOE). The Taguchi method includes an orthogonal array of factors, a Signal-to-Noise ratio (S/N), Analysis of Variance (ANOVA), which were used to determine the optimum condition levels for aluminum alloy 6066 anodizing, and to analyze the effect of these conditions on thickness and hardness. It was found that the most effective factor on thickness and micro-hardness is the concentration of the electrolyte. Optimization test was carried out by Taguchi optimization test and the optimal conditions were determined. Finally, the anodizing was carried out on aluminum sample under the optimal conditions then scanned by SEM. The thickness and micro hardness obtained at the optimal conditions were 25μm, and 640Hv, respectively.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49538230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.18311/JSST/2018/16222
Isai Dharma Rao, C. Prasad, K. Santarao
The sliding motion between worm and worm wheel is the inherent factor that makes the worm and worm wheel drives less efficient among all the gear drives. Efficiency of these gears varies between 40 to 90%. They need good lubricants, which has high heat dissipation capacity and low coefficient of friction for improving the efficiency. The lubricants considered in the current investigation play a significant role in decreasing the power losses in gearbox besides the geometry of the gears. Nano blended lubricants are found to have efficient tribological and thermal physical properties such as, less frictional coefficient and high heat transfer coefficient. Al 2 O 3 Nano particles of 30 nm size dispersed in SAE 140 mineral oil at different volume fractions resulted decrease in frictional coefficient and found varying from 0.1 to 0.5% nano particle volume fractions. Further, heat transfer coefficient is enhanced by 46.35% for volume fraction of 0.5% and also temperature rise of nano blended lubricant was found to be less than that of base lubricant. The overall efficiency of the selected gearbox with which the experimentation has been done was found to be increased with usage of nano blended lubricant. The performance of the gearbox using nano lubricant at 0.5 volume percent is found improved by 4.85 and 7.86% at operating temperatures 35 and 60 o C, respectively compared to the performance of the gearbox using base lubricant.
{"title":"Experimental Investigation to Enhance the Performance of High Speed Reduction Gearbox using Nano Blended Lubricants","authors":"Isai Dharma Rao, C. Prasad, K. Santarao","doi":"10.18311/JSST/2018/16222","DOIUrl":"https://doi.org/10.18311/JSST/2018/16222","url":null,"abstract":"The sliding motion between worm and worm wheel is the inherent factor that makes the worm and worm wheel drives less efficient among all the gear drives. Efficiency of these gears varies between 40 to 90%. They need good lubricants, which has high heat dissipation capacity and low coefficient of friction for improving the efficiency. The lubricants considered in the current investigation play a significant role in decreasing the power losses in gearbox besides the geometry of the gears. Nano blended lubricants are found to have efficient tribological and thermal physical properties such as, less frictional coefficient and high heat transfer coefficient. Al 2 O 3 Nano particles of 30 nm size dispersed in SAE 140 mineral oil at different volume fractions resulted decrease in frictional coefficient and found varying from 0.1 to 0.5% nano particle volume fractions. Further, heat transfer coefficient is enhanced by 46.35% for volume fraction of 0.5% and also temperature rise of nano blended lubricant was found to be less than that of base lubricant. The overall efficiency of the selected gearbox with which the experimentation has been done was found to be increased with usage of nano blended lubricant. The performance of the gearbox using nano lubricant at 0.5 volume percent is found improved by 4.85 and 7.86% at operating temperatures 35 and 60 o C, respectively compared to the performance of the gearbox using base lubricant.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67530332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.18311/JSST/2018/20118
R. Sampathkumar, A. Aswathy, V. Balachandar
Composites of polypropylene with different weight percentages of ZnO-TiO 2 core-shell nanoparticles were prepared by the combination of solution and mixture melting methods. Dielectric properties of polypropylene composite films were studied at frequencies ranging from 50 Hz to 5 MHz at four different temperatures (313, 333, 353, and 373 K). It is observed that the dielectric constant reduces quickly in the low-frequency range followed by a near frequency independent behavior above 1 KHz. The dielectric properties of composites at low frequency can be explained by interfacial polarization or Maxwell-Wagner-Sillars effect. It is also observed that the dielectric constant reaches the maximum value at 3 wt% of ZnO-TiO 2 , which is the percolation threshold of nanocomposite. As the weight percentage of ZnO-TiO 2 increases beyond the percolation threshold up to 7%, the dielectric constant of the nanocomposites decreases. The dielectric loss of the composites follows the similar trend with frequency as the dielectric constant. A sharp increase in the dielectric loss of the nanocomposite observed near the percolation threshold is due to leakage current produced by the formation of conductive network by ZnO-TiO 2 core-shell nanoparticles. Further, peaks in the loss tangent observed for the nanocomposite systems indicating the appearance of a relaxation process. These relaxations peaks were shifted to higher frequencies as the particle content increased, since relaxation processes were influenced by the interfacial polarization effect which generated electric charge accumulation around the ZnO-TiO 2 core-shell nanoparticles.
{"title":"Dielectric Properties of Composites of Polypropylene with Zno-TiO2 Core-Shell Nanoparticles","authors":"R. Sampathkumar, A. Aswathy, V. Balachandar","doi":"10.18311/JSST/2018/20118","DOIUrl":"https://doi.org/10.18311/JSST/2018/20118","url":null,"abstract":"Composites of polypropylene with different weight percentages of ZnO-TiO 2 core-shell nanoparticles were prepared by the combination of solution and mixture melting methods. Dielectric properties of polypropylene composite films were studied at frequencies ranging from 50 Hz to 5 MHz at four different temperatures (313, 333, 353, and 373 K). It is observed that the dielectric constant reduces quickly in the low-frequency range followed by a near frequency independent behavior above 1 KHz. The dielectric properties of composites at low frequency can be explained by interfacial polarization or Maxwell-Wagner-Sillars effect. It is also observed that the dielectric constant reaches the maximum value at 3 wt% of ZnO-TiO 2 , which is the percolation threshold of nanocomposite. As the weight percentage of ZnO-TiO 2 increases beyond the percolation threshold up to 7%, the dielectric constant of the nanocomposites decreases. The dielectric loss of the composites follows the similar trend with frequency as the dielectric constant. A sharp increase in the dielectric loss of the nanocomposite observed near the percolation threshold is due to leakage current produced by the formation of conductive network by ZnO-TiO 2 core-shell nanoparticles. Further, peaks in the loss tangent observed for the nanocomposite systems indicating the appearance of a relaxation process. These relaxations peaks were shifted to higher frequencies as the particle content increased, since relaxation processes were influenced by the interfacial polarization effect which generated electric charge accumulation around the ZnO-TiO 2 core-shell nanoparticles.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48179593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.18311/JSST/2018/20097
S. Baskar, P. Nalini
Si-rich Silicon carbide thin films have grown popularity in the past decade for various opto-electronic applications. Post processing of these thin films at temperature higher than 1000 o C usually lead to phase transformations to form Si nanoclusters embedded in amorphous SiC deposited by sputtering on thin films. However, the processing technique is crucial to avoid contaminants, and obtain good quality films. Therefore, a novel in-situ annealing approach within the deposition chamber is carried out at temperatures lower than usual. The influence of in-situ annealing on the material property is meticulously studied by means of Spectroscopic Ellipsometry (SE), Diffused Reflectance Spectroscopy (DRS), and Fourier Transform Infrared Spectroscopy (FTIR). In SE, the spectra are fitted using various models; the refractive index values confirm the Si-richness of the film. The band gap (2.5 to 1.5 eV) is extracted from UV spectra using Tauc plot, which confirms the coexistence of the multiphase structure with the possibility of having Si-NC with different dimensions. The results obtained are promising for optoelectronic device applications.
{"title":"Influence of In-Situ Annealing of Si-Rich Silicon Carbide Thin Films","authors":"S. Baskar, P. Nalini","doi":"10.18311/JSST/2018/20097","DOIUrl":"https://doi.org/10.18311/JSST/2018/20097","url":null,"abstract":"Si-rich Silicon carbide thin films have grown popularity in the past decade for various opto-electronic applications. Post processing of these thin films at temperature higher than 1000 o C usually lead to phase transformations to form Si nanoclusters embedded in amorphous SiC deposited by sputtering on thin films. However, the processing technique is crucial to avoid contaminants, and obtain good quality films. Therefore, a novel in-situ annealing approach within the deposition chamber is carried out at temperatures lower than usual. The influence of in-situ annealing on the material property is meticulously studied by means of Spectroscopic Ellipsometry (SE), Diffused Reflectance Spectroscopy (DRS), and Fourier Transform Infrared Spectroscopy (FTIR). In SE, the spectra are fitted using various models; the refractive index values confirm the Si-richness of the film. The band gap (2.5 to 1.5 eV) is extracted from UV spectra using Tauc plot, which confirms the coexistence of the multiphase structure with the possibility of having Si-NC with different dimensions. The results obtained are promising for optoelectronic device applications.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45213765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.18311/JSST/2018/20171
D. T. Nguyen, Minh X. Vu, H. Nguyen
The Fly Ash (FA) was treated by NaOH solution in order to transform into the zeolite-like structure. Poly(1,5- diaminonaphthalene) [p(1,5-DAN)] was synthesized via in-situ chemical oxidation on the surface of NaOH-Treated Fly Ash (TFA) to form p(1,5-DAN)/TFA composite. The p(1,5-DAN)/TFA composite was used as a novel sorbent for removal of Cr(VI) ions from aqueous solutions. The maximum adsorption capacity (at pH 2, 298 K) calculated according to Langmuir isotherm model was 4.4 mg/g. This result suggested that p(1,5-DAN)/TFA was a promising adsorbent for Cr(VI) ions in the environmental treatment.
{"title":"Surface Modification of Fly Ash by Poly(1,5-Diaminonaphthalene) for Removal of Hexavalent Chromium from Water","authors":"D. T. Nguyen, Minh X. Vu, H. Nguyen","doi":"10.18311/JSST/2018/20171","DOIUrl":"https://doi.org/10.18311/JSST/2018/20171","url":null,"abstract":"The Fly Ash (FA) was treated by NaOH solution in order to transform into the zeolite-like structure. Poly(1,5- diaminonaphthalene) [p(1,5-DAN)] was synthesized via in-situ chemical oxidation on the surface of NaOH-Treated Fly Ash (TFA) to form p(1,5-DAN)/TFA composite. The p(1,5-DAN)/TFA composite was used as a novel sorbent for removal of Cr(VI) ions from aqueous solutions. The maximum adsorption capacity (at pH 2, 298 K) calculated according to Langmuir isotherm model was 4.4 mg/g. This result suggested that p(1,5-DAN)/TFA was a promising adsorbent for Cr(VI) ions in the environmental treatment.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42483347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.18311/JSST/2018/16027
U. Raghavender, K. Kumar, E. R. Reddy, A. Reddy
Anodization of Ti-12 alloy has been carried out in various electrolytes at different constant current densities and temperatures. Kinetics of anodic films was studied in different electrolytes at different constant current densities ranging from 4mAcm -2 to 64mAcm -2 and at different temperatures ranging from 298 to 338K. From the plots of formation voltage (V) vs time (t), rates of formation were calculated. The rate of film formation and breakdown voltage increase with increase in constant current density while decrease with increase in temperature. The kinetics were found better in sulphamic acid electrolyte at room temperature compared to other electrolytes at the same anodizing conditions.
{"title":"Anodic Behaviour of Ti-12 in Various Electrolytes","authors":"U. Raghavender, K. Kumar, E. R. Reddy, A. Reddy","doi":"10.18311/JSST/2018/16027","DOIUrl":"https://doi.org/10.18311/JSST/2018/16027","url":null,"abstract":"Anodization of Ti-12 alloy has been carried out in various electrolytes at different constant current densities and temperatures. Kinetics of anodic films was studied in different electrolytes at different constant current densities ranging from 4mAcm -2 to 64mAcm -2 and at different temperatures ranging from 298 to 338K. From the plots of formation voltage (V) vs time (t), rates of formation were calculated. The rate of film formation and breakdown voltage increase with increase in constant current density while decrease with increase in temperature. The kinetics were found better in sulphamic acid electrolyte at room temperature compared to other electrolytes at the same anodizing conditions.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41424773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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