Pub Date : 2020-08-20DOI: 10.18311/JSST/2020/24037
R. Gupta, S. Chouhan, P. Ganesh, R. Kaul
This paper describes an experimental study on the effect of Ultra-Violet (UV) exposure on the electrochemical corrosion behavior of 304L stainless steel in 0.1M H2SO4 and 0.5M NaCl medium. The results of study demonstrate that in NaCl medium, exposure of both UV-A and UV-C shifts the Open Circuit Potential (OCP) in active direction (less noble) as compared to the specimen without UV exposure which indicates less stable passive film. While in sulphuric acid both UV-A and UV-C shifts OCP in noble direction which reflects the stability nature of passive film. In H2SO4 medium, exposure of both UV-A and UV-C assist in improving passivity which is indicated by lower passive current density. In NaCl medium, exposure of both UV-A and UV-C, decrease the pitting corrosion resistance as indicated by lower Epit (pitting potential) and higher Icorr (corrosion current density). In H2SO4 uniform dissolution was observed after each polarization experiment as shown in optical micrographs. In NaCl medium pitting sites are more under both type UV exposures as revealed by microstructure after polarization experiment. EIS (Nyquist plots) showed that exposure of both UV-A and UV-C in NaCl medium specimens have lower polarization resistance (Rp) than without UV exposure. Lower Rp confirms lesser protectiveness of passive film. In case of H2SO4, higher arc radius (Rp) is observed under UV exposure for both UV-A and UV-C.
{"title":"Influence of UV Irradiation on Corrosion Behavior of 304L SS in 0.1M H2SO4 and 0.5M NaCl","authors":"R. Gupta, S. Chouhan, P. Ganesh, R. Kaul","doi":"10.18311/JSST/2020/24037","DOIUrl":"https://doi.org/10.18311/JSST/2020/24037","url":null,"abstract":"This paper describes an experimental study on the effect of Ultra-Violet (UV) exposure on the electrochemical corrosion behavior of 304L stainless steel in 0.1M H2SO4 and 0.5M NaCl medium. The results of study demonstrate that in NaCl medium, exposure of both UV-A and UV-C shifts the Open Circuit Potential (OCP) in active direction (less noble) as compared to the specimen without UV exposure which indicates less stable passive film. While in sulphuric acid both UV-A and UV-C shifts OCP in noble direction which reflects the stability nature of passive film. In H2SO4 medium, exposure of both UV-A and UV-C assist in improving passivity which is indicated by lower passive current density. In NaCl medium, exposure of both UV-A and UV-C, decrease the pitting corrosion resistance as indicated by lower Epit (pitting potential) and higher Icorr (corrosion current density). In H2SO4 uniform dissolution was observed after each polarization experiment as shown in optical micrographs. In NaCl medium pitting sites are more under both type UV exposures as revealed by microstructure after polarization experiment. EIS (Nyquist plots) showed that exposure of both UV-A and UV-C in NaCl medium specimens have lower polarization resistance (Rp) than without UV exposure. Lower Rp confirms lesser protectiveness of passive film. In case of H2SO4, higher arc radius (Rp) is observed under UV exposure for both UV-A and UV-C.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46901117","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 : 2020-08-20DOI: 10.18311/JSST/2020/24268
Baljit Singh, A. Mohanty
Because of the inherent brittleness property of monolithic epoxy, it fails to prevent crack propagation and is hence vulnerable to the catastrophic failure. Nano-fillers, such as CNT/Graphene (GnP)/Nanodiamond (NDs) and other carbonaceous materials increase its ability to withstand crack propagation thus its fracture strength propitiously improved. This paper studies compressive properties of MWCNT/GnP/NDs on epoxy based composite material. A static uniaxial compression test was conducted in order to study the effect of these fillers on the compressive stress-strain behaviour of such composites. In this study, the MWCNT/GnP/NDs are added individually as 0.2 wt% and for the hybrid composite, 0.1 wt. % of NDs is added separately along with 0.1 wt% of MWCNT and GnP to the epoxy matrix. The bonding between MWCNT/GnP/NDs with the epoxy matrix is confirmed by microscopic observations. The results showed that the individual addition of 0.2 wt% of MWCNT/GnP/NDs, improves the compressive strength whereas the hybrid composite produced a declining trend. The reverse trend was also observed for the modulus value of the above mentioned composite materials.
{"title":"Compressive Strength Evaluation of Nanodiamond/ MWCNT/Graphene Reinforced Novel Hybrid Polymer Nano Composites","authors":"Baljit Singh, A. Mohanty","doi":"10.18311/JSST/2020/24268","DOIUrl":"https://doi.org/10.18311/JSST/2020/24268","url":null,"abstract":"Because of the inherent brittleness property of monolithic epoxy, it fails to prevent crack propagation and is hence vulnerable to the catastrophic failure. Nano-fillers, such as CNT/Graphene (GnP)/Nanodiamond (NDs) and other carbonaceous materials increase its ability to withstand crack propagation thus its fracture strength propitiously improved. This paper studies compressive properties of MWCNT/GnP/NDs on epoxy based composite material. A static uniaxial compression test was conducted in order to study the effect of these fillers on the compressive stress-strain behaviour of such composites. In this study, the MWCNT/GnP/NDs are added individually as 0.2 wt% and for the hybrid composite, 0.1 wt. % of NDs is added separately along with 0.1 wt% of MWCNT and GnP to the epoxy matrix. The bonding between MWCNT/GnP/NDs with the epoxy matrix is confirmed by microscopic observations. The results showed that the individual addition of 0.2 wt% of MWCNT/GnP/NDs, improves the compressive strength whereas the hybrid composite produced a declining trend. The reverse trend was also observed for the modulus value of the above mentioned composite materials.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42543867","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 : 2020-08-20DOI: 10.18311/JSST/2020/24184
G. M. T. Basha, B. Venkateshwarlu
Tungsten Carbide-20 weight % Cobalt (WC-20 wt% Co) coatings were extensively used material to achieve a combination of extreme hardness and excellent strength. Hence, an effort has been made to improve the toughening properties of WC-Co coatings through reinforcement of Carbon Nano-Tubes (CNTs) using High-Velocity Oxy-Fuel (HVOF) spraying process. In this work, 2 wt%, 4 wt%, and 6 wt% of CNTs were blended by the ball milling process with WC-Co powders. These composed powders were deposited by HVOF process on to the plain mild steel substrates. The scratch test analysis on as-sprayed coatings showed that due to the addition of CNTs on WC-Co coatings, the resistance to penetrate the coating surface increased. Also, by varying the percentage of CNTs in the coating system, the pores were reduced. This phenomenon is attributed to the toughening mechanism by forming a CNT bridge which avoids the formation of internal cracks.
{"title":"Scratch Resistance of High Velocity Oxy-Fuel Sprayed WC-20% Co Coatings Reinforced with Carbon Nanotubes","authors":"G. M. T. Basha, B. Venkateshwarlu","doi":"10.18311/JSST/2020/24184","DOIUrl":"https://doi.org/10.18311/JSST/2020/24184","url":null,"abstract":"Tungsten Carbide-20 weight % Cobalt (WC-20 wt% Co) coatings were extensively used material to achieve a combination of extreme hardness and excellent strength. Hence, an effort has been made to improve the toughening properties of WC-Co coatings through reinforcement of Carbon Nano-Tubes (CNTs) using High-Velocity Oxy-Fuel (HVOF) spraying process. In this work, 2 wt%, 4 wt%, and 6 wt% of CNTs were blended by the ball milling process with WC-Co powders. These composed powders were deposited by HVOF process on to the plain mild steel substrates. The scratch test analysis on as-sprayed coatings showed that due to the addition of CNTs on WC-Co coatings, the resistance to penetrate the coating surface increased. Also, by varying the percentage of CNTs in the coating system, the pores were reduced. This phenomenon is attributed to the toughening mechanism by forming a CNT bridge which avoids the formation of internal cracks.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46862117","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 : 2020-08-20DOI: 10.18311/JSST/2020/24328
S. Murugesan, J. Anitalett, S. Sabitha
Pasteurized cow milk (whole milk) was used in the present study and also fat was removed from the whole milk to obtain skimmed milk. Whey is the liquid remaining after milk has been curded and strained during the manufacture of cheese. The sample was filtered using a Whatman filter paper to separate the precipitate. The filtrate thus obtained is called whey (devoid of casein and fat). The micrographs of whole milk, skimmed milk and whey were obtained using an inverted phase contrast microscopy. The hydrodynamic size and zeta potential of the samples were obtained using Dynamic light scattering technique. Atomic force microscopy was also performed to understand the surface morphology of whole milk, skimmed milk and whey on mica substrate.
{"title":"Identification and Characterization of whey Protein, Casein Micelles and Fat Globules in Cow Milk","authors":"S. Murugesan, J. Anitalett, S. Sabitha","doi":"10.18311/JSST/2020/24328","DOIUrl":"https://doi.org/10.18311/JSST/2020/24328","url":null,"abstract":"Pasteurized cow milk (whole milk) was used in the present study and also fat was removed from the whole milk to obtain skimmed milk. Whey is the liquid remaining after milk has been curded and strained during the manufacture of cheese. The sample was filtered using a Whatman filter paper to separate the precipitate. The filtrate thus obtained is called whey (devoid of casein and fat). The micrographs of whole milk, skimmed milk and whey were obtained using an inverted phase contrast microscopy. The hydrodynamic size and zeta potential of the samples were obtained using Dynamic light scattering technique. Atomic force microscopy was also performed to understand the surface morphology of whole milk, skimmed milk and whey on mica substrate.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49457279","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 : 2020-08-20DOI: 10.18311/JSST/2020/23282
S. Mitra
Protein adsorption on solid surfaces is an immensely complex event comprising versatile biological and physico-chemical factors. This review focuses to ascertain the nature and biocompatibility of solid matrices essential for the medical needs during prosthetic implantations. It deals with number of important factors; nature of the biomaterial surfaces, the native protein structure, and induced configurational changes during the adsorbed state, andphysico-chemical influences liable for the event. The adsorption process demonstrates that solid surfaces are enabling to alter the protein structure. The conversion of neutral zymogens factor XII, and factor VII (FXII and FVII) to active enzymatic state (FXIIa and FVIIa) initiating the blood coagulation cascade following intrinsic or extrinsic pathway is a prime example regarding the configuration alteration during adsorbed state compared to its nativestate. Additionally, the activation of the complement cascade arises as a result of immune activation due to the adsorbed proteins on solid matrices. It is well known that interfacial tension compels the protein molecules to alter their structure, and is the prime factor behind the configuration transformation. Influences like contact angle, wettability, zeta potential and hydrophobicity along with other inter-aligned forces are involved. It is found that hydrophobic surfaces allow more proteins to bind but fail to activate the coagulation cascade. Contrarily, hydrophilic surfaces despite the feeble adsorption ability impose adequate changes to induce the enzymatic action. The nature of adsorption at the stationary state has been explained following the Gibbs' model of surface excess, Langmuir or any of the equivalent paradigms. But uniqueness in adsorption behavior is noticed in the ‘Vroman effect' while undergoing multiple protein interaction on the solid surfaces. Additionally, the property of cell adhesion heavily relies on the surface matter. Hydrophobicity, surface charge, chemical composition, and topography concertedly play crucial role. Further, prior adsorption of proteins on the adsorbent imposes profound effect on the cell and microbial adhesions which obviously depends on the character of proteins, and cells including the surface chemical composition of the adsorbents. The incident of bio-fouling which often enforces harmful effect arising from various implants is primarily instigated by the adsorption of proteins leading to subsequent invasion prompted by the immune cells. For avoidance, special categories of biomaterials are in the process of manufacturing. Despite having numerous adverse effects, cellular adhesion also shows few beneficial roles, like enhancing the growth of human vein endothelium cells and neurons. The adhesion of bacteria or microorganisms on many solid surfaces induces significantly different effects maintaining their longer survival period.
{"title":"Protein Adsorption on Biomaterial Surfaces: Subsequent Conformational and Biological Consequences – A Review","authors":"S. Mitra","doi":"10.18311/JSST/2020/23282","DOIUrl":"https://doi.org/10.18311/JSST/2020/23282","url":null,"abstract":"Protein adsorption on solid surfaces is an immensely complex event comprising versatile biological and physico-chemical factors. This review focuses to ascertain the nature and biocompatibility of solid matrices essential for the medical needs during prosthetic implantations. It deals with number of important factors; nature of the biomaterial surfaces, the native protein structure, and induced configurational changes during the adsorbed state, andphysico-chemical influences liable for the event. The adsorption process demonstrates that solid surfaces are enabling to alter the protein structure. The conversion of neutral zymogens factor XII, and factor VII (FXII and FVII) to active enzymatic state (FXIIa and FVIIa) initiating the blood coagulation cascade following intrinsic or extrinsic pathway is a prime example regarding the configuration alteration during adsorbed state compared to its nativestate. Additionally, the activation of the complement cascade arises as a result of immune activation due to the adsorbed proteins on solid matrices. It is well known that interfacial tension compels the protein molecules to alter their structure, and is the prime factor behind the configuration transformation. Influences like contact angle, wettability, zeta potential and hydrophobicity along with other inter-aligned forces are involved. It is found that hydrophobic surfaces allow more proteins to bind but fail to activate the coagulation cascade. Contrarily, hydrophilic surfaces despite the feeble adsorption ability impose adequate changes to induce the enzymatic action. The nature of adsorption at the stationary state has been explained following the Gibbs' model of surface excess, Langmuir or any of the equivalent paradigms. But uniqueness in adsorption behavior is noticed in the ‘Vroman effect' while undergoing multiple protein interaction on the solid surfaces. Additionally, the property of cell adhesion heavily relies on the surface matter. Hydrophobicity, surface charge, chemical composition, and topography concertedly play crucial role. Further, prior adsorption of proteins on the adsorbent imposes profound effect on the cell and microbial adhesions which obviously depends on the character of proteins, and cells including the surface chemical composition of the adsorbents. The incident of bio-fouling which often enforces harmful effect arising from various implants is primarily instigated by the adsorption of proteins leading to subsequent invasion prompted by the immune cells. For avoidance, special categories of biomaterials are in the process of manufacturing. Despite having numerous adverse effects, cellular adhesion also shows few beneficial roles, like enhancing the growth of human vein endothelium cells and neurons. The adhesion of bacteria or microorganisms on many solid surfaces induces significantly different effects maintaining their longer survival period.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44837244","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 : 2020-08-20DOI: 10.18311/JSST/2020/22591
G. Balakrishnan, R. Velavan, S. Naser
In the present work, NiO thin films were prepared on glass and silicon substrates by Radio Frequency (RF) magnetron sputtering technique. NiO films are deposited with the argon flow rate of 10 and 20 sccm at room temperature. The 2” NiO target was used for the deposition of NiO films and was characterized using X-Ray Diffraction (XRD), Photoluminescence (PL), UV-Visible spectroscopy and Hall Effect measurement to study the structural, optical and electrical properties of the films. The XRD pattern shows the small intense peak, revealing the nanocrystallinity of the NiO film. The transmittance spectra indicated the high transmittance in the order of ~90%. The photoluminescence studies indicated the bandgap of 3.52 eV. The Hall Effect studies demonstrated the p-type behaviour of NiO films. The film showed the p-type conductivity and hole concentration ∼5.34 x1019 cm−3 with Hall mobility of ∼612 cm2/V·s for the film deposited at 20 sccm.
{"title":"Characterization of P-type Nickel Oxide (NiO) Thin Films Prepared by RF Magnetron Sputtering","authors":"G. Balakrishnan, R. Velavan, S. Naser","doi":"10.18311/JSST/2020/22591","DOIUrl":"https://doi.org/10.18311/JSST/2020/22591","url":null,"abstract":"In the present work, NiO thin films were prepared on glass and silicon substrates by Radio Frequency (RF) magnetron sputtering technique. NiO films are deposited with the argon flow rate of 10 and 20 sccm at room temperature. The 2” NiO target was used for the deposition of NiO films and was characterized using X-Ray Diffraction (XRD), Photoluminescence (PL), UV-Visible spectroscopy and Hall Effect measurement to study the structural, optical and electrical properties of the films. The XRD pattern shows the small intense peak, revealing the nanocrystallinity of the NiO film. The transmittance spectra indicated the high transmittance in the order of ~90%. The photoluminescence studies indicated the bandgap of 3.52 eV. The Hall Effect studies demonstrated the p-type behaviour of NiO films. The film showed the p-type conductivity and hole concentration ∼5.34 x1019 cm−3 with Hall mobility of ∼612 cm2/V·s for the film deposited at 20 sccm.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49408460","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 : 2020-08-20DOI: 10.18311/JSST/2020/23780
R. Benaddi, K. E. Harfi, F. Aziz, F. Berrekhis, N. Ouazzani
In this work, we studied the elimination of phenol compounds from phenolic solutions and Oil Mill Waste Water (OMWW) by adsorption method. The adsorbents used are natural phosphate rock coming from Khouribga phosphate mine (Morocco) and an Apatite synthesized from this phosphate by a dissolution–precipitation reactions. Results obtained showed that the structure of natural phosphate and synthesized apatite are respectively Ca9.55(PO4)4.96F1.96 (CO3)1.283 and (Ca10(OH)2(PO4)6). Synthesized apatite has a higher specific surface than natural phosphate (193.62m2/g). The adsorption study showed that the synthesized apatite can be used as an adsorbent to remove phenol from water with very fast reaction kinetics (about 10 min) and an adsorption capacity equal to 15mg/g. The optimal adsorption capacity was found in low values of temperature and in neutral pH. Adsorption kinetics of phenol solution on the two adsorbents can be described by an equation corresponding to a pseudo second order. Freundlich model fitted well with the adsorption isotherms more than the Langmuir model. Characterization of olive mill wastewater shows that, phenol index equal to 0.39 g/l and chemical oxygen demand COD equal to 158 g/l. The treatment of OMWW by adsorption method on the two adsorbents shows that the use of natural phosphate as adsorbent reduced phenol index by 23% and (COD) by 35% while using synthesized apatite reduced phenol index by 30% and COD by 38%.
{"title":"Removal of Phenolic Compounds from Synthetic Solution and Oil Mill Waste Water by Adsorption onto Nanoparticles Synthesized from Phosphate Rock","authors":"R. Benaddi, K. E. Harfi, F. Aziz, F. Berrekhis, N. Ouazzani","doi":"10.18311/JSST/2020/23780","DOIUrl":"https://doi.org/10.18311/JSST/2020/23780","url":null,"abstract":"In this work, we studied the elimination of phenol compounds from phenolic solutions and Oil Mill Waste Water (OMWW) by adsorption method. The adsorbents used are natural phosphate rock coming from Khouribga phosphate mine (Morocco) and an Apatite synthesized from this phosphate by a dissolution–precipitation reactions. Results obtained showed that the structure of natural phosphate and synthesized apatite are respectively Ca9.55(PO4)4.96F1.96 (CO3)1.283 and (Ca10(OH)2(PO4)6). Synthesized apatite has a higher specific surface than natural phosphate (193.62m2/g). The adsorption study showed that the synthesized apatite can be used as an adsorbent to remove phenol from water with very fast reaction kinetics (about 10 min) and an adsorption capacity equal to 15mg/g. The optimal adsorption capacity was found in low values of temperature and in neutral pH. Adsorption kinetics of phenol solution on the two adsorbents can be described by an equation corresponding to a pseudo second order. Freundlich model fitted well with the adsorption isotherms more than the Langmuir model. Characterization of olive mill wastewater shows that, phenol index equal to 0.39 g/l and chemical oxygen demand COD equal to 158 g/l. The treatment of OMWW by adsorption method on the two adsorbents shows that the use of natural phosphate as adsorbent reduced phenol index by 23% and (COD) by 35% while using synthesized apatite reduced phenol index by 30% and COD by 38%.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49160074","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 : 2020-01-31DOI: 10.18311/JSST/2019/22436
Hesham Elzanaty, R. Mostafa
In this study, the electro-chemical behavior of Udimet700 alloys is studied in acidic media at 25°C. It deals with the corrosion inhibition process of nickel–based (Udimet700) alloy in 1M–HCl solution by some organic derivatives. The methods used include electro–chemical frequency modulation technique, electro–chemical impedance spectroscopy, and potentio–dynamic polarization. The derivatives are considered as mixed–type inhibitor depending on potentio–dynamic polarization analysis. Scanning electron microscope examination is executed to study the morphology of Udimet700 surface after immersion in a solution in the case of presence and absence of derivatives. The results of this research reveal that the inhibitors are absorbed by Udimet700 alloy surface and they insulate it from the acidic medium. The compound (C16H17) among the tested organic derivatives plays the best role as an inhibitor of the alloy in 1M–HCl.
{"title":"Influence of Some Organic Derivatives on the Corrosion Inhibition of Udimet700 Alloy in 1 M HCl Solution","authors":"Hesham Elzanaty, R. Mostafa","doi":"10.18311/JSST/2019/22436","DOIUrl":"https://doi.org/10.18311/JSST/2019/22436","url":null,"abstract":"In this study, the electro-chemical behavior of Udimet700 alloys is studied in acidic media at 25°C. It deals with the corrosion inhibition process of nickel–based (Udimet700) alloy in 1M–HCl solution by some organic derivatives. The methods used include electro–chemical frequency modulation technique, electro–chemical impedance spectroscopy, and potentio–dynamic polarization. The derivatives are considered as mixed–type inhibitor depending on potentio–dynamic polarization analysis. Scanning electron microscope examination is executed to study the morphology of Udimet700 surface after immersion in a solution in the case of presence and absence of derivatives. The results of this research reveal that the inhibitors are absorbed by Udimet700 alloy surface and they insulate it from the acidic medium. The compound (C16H17) among the tested organic derivatives plays the best role as an inhibitor of the alloy in 1M–HCl.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47946105","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 : 2020-01-31DOI: 10.18311/JSST/2019/21455
Inaam H. Ali, Sameer H. Kareem
The surface adsorption properties of mixed binary surfactants containing hexadecyl benzylammonium chloride (HDBAC) and Tween 20 in aqueous solutions were studied at different temperatures (288-318K) using tensiometry techniques. The interaction parameters and surface activity for both individual and mixed surfactants systems, the Critical Micelle Concentration (CMC), maximum surface excess concentration (Γmax) and minimum surface area per surfactant molecule (Amin) at the air-water interface were determined. Also, the parameters related to synergism in surface activity such as adsorption efficiency (pC20) and CMC/C20 were calculated. The results obtained reveal that the binary mixed system possess CMC values lower than its components and these values decrease with increasing the concentration of Tween 20 in the solution. This behavior shows non-ideal synergism of the mixing process. The values of molecular interaction parameters βσ and the mole fraction of components at the air-water interface X1σ are calculated on the basis of Rosen's model and showed that the interaction parameter of the adsorbed monolayer is always negative and has a higher negative value for 0.9 Tween mole fractions.
{"title":"Interfacial Interaction of Binary Mixtures of Surfactants Hexadecyl Benzylammonium Chloride (HDBAC) and Tween 20 in Aqueous Solutions","authors":"Inaam H. Ali, Sameer H. Kareem","doi":"10.18311/JSST/2019/21455","DOIUrl":"https://doi.org/10.18311/JSST/2019/21455","url":null,"abstract":"The surface adsorption properties of mixed binary surfactants containing hexadecyl benzylammonium chloride (HDBAC) and Tween 20 in aqueous solutions were studied at different temperatures (288-318K) using tensiometry techniques. The interaction parameters and surface activity for both individual and mixed surfactants systems, the Critical Micelle Concentration (CMC), maximum surface excess concentration (Γmax) and minimum surface area per surfactant molecule (Amin) at the air-water interface were determined. Also, the parameters related to synergism in surface activity such as adsorption efficiency (pC20) and CMC/C20 were calculated. The results obtained reveal that the binary mixed system possess CMC values lower than its components and these values decrease with increasing the concentration of Tween 20 in the solution. This behavior shows non-ideal synergism of the mixing process. The values of molecular interaction parameters βσ and the mole fraction of components at the air-water interface X1σ are calculated on the basis of Rosen's model and showed that the interaction parameter of the adsorbed monolayer is always negative and has a higher negative value for 0.9 Tween mole fractions.","PeriodicalId":17031,"journal":{"name":"Journal of Surface Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43350387","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 : 2020-01-31DOI: 10.18311/JSST/2019/22306
Rachna Sinha, G. Chauhan, A. Singh, Arinjay Kumar
Present work evaluates the ability of Aspergillus oryzae and commercial dry Baker's yeast to effectively remove Cu2+ ions from aqueous solutions. Batch experiments were carried out in order to analyze sorption behavior of metal-sorbent system at different biosorbent dosage, and initial metal concentration. Various pre-treatment methods were adopted to modify the biomass, and effect of pre-treatment was investigated on biosorption efficiency. Till now, very few efforts are dedicated for application of immobilized biosorbents in literature therefore further investigations were done on the biosorption efficiency of biomass immobilized in a natural matrix which might augment stability, mechanical strength, and reusability of the biomass. Approximately 86 and 95% biosorption of copper was attained under optimum reaction conditions using Loofah immobilized with Baker's yeast, and A. oryzae, respectively. Desorption efficiency of the immobilized biomass was evaluated by performing successive biosorption-desorption cycles. Successful regeneration of Loofah sponge loaded with immobilized biosorbent was illustrated by desorbing more than 95% copper. Characterization studies were performed to examine the changes in surface morphology, and surface chemistry before and after adsorption.
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