Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1948242
I. Anshori, Lavita Nuraviana Rizalputri, Raih Rona Althof, Steven Sean Surjadi, S. Harimurti, G. Gumilar, B. Yuliarto, M. Handayani
Abstract Dopamine (DA) is an important neurotransmitter in the kidney, cardiovascular system, and central nervous system, which abnormality is associated with many diseases. In this work, we synthesized a functionalized multi-walled carbon nanotube/silver nanoparticle (f-MWCNT/AgNP) nanocomposites as the biosensing material to detect DA. The SEM, EDS, and TEM characterizations indicated the success of the functionalization process with MWCNT as the base material. The values of the linear range, the limit of detection (LOD), and the selectivity of the nanocomposite were all obtained from the Differential Pulse Voltammetry (DPV) measurements. The obtained LOD value was 0.2778 µM in the linear range of 0–8 µM, which is lower than the required concentration value for detecting DA in human urine (0.3–3 µM). The biosensor’s high selectivity on DA with the presence of other human-related biofluids was also reported. These results show that f-MWCNT/AgNP nanocomposites are a promising biosensor material for the detection of DA. Graphical Abstract
{"title":"Functionalized multi-walled carbon nanotube/silver nanoparticle (f-MWCNT/AgNP) nanocomposites as non-enzymatic electrochemical biosensors for dopamine detection","authors":"I. Anshori, Lavita Nuraviana Rizalputri, Raih Rona Althof, Steven Sean Surjadi, S. Harimurti, G. Gumilar, B. Yuliarto, M. Handayani","doi":"10.1080/20550324.2021.1948242","DOIUrl":"https://doi.org/10.1080/20550324.2021.1948242","url":null,"abstract":"Abstract Dopamine (DA) is an important neurotransmitter in the kidney, cardiovascular system, and central nervous system, which abnormality is associated with many diseases. In this work, we synthesized a functionalized multi-walled carbon nanotube/silver nanoparticle (f-MWCNT/AgNP) nanocomposites as the biosensing material to detect DA. The SEM, EDS, and TEM characterizations indicated the success of the functionalization process with MWCNT as the base material. The values of the linear range, the limit of detection (LOD), and the selectivity of the nanocomposite were all obtained from the Differential Pulse Voltammetry (DPV) measurements. The obtained LOD value was 0.2778 µM in the linear range of 0–8 µM, which is lower than the required concentration value for detecting DA in human urine (0.3–3 µM). The biosensor’s high selectivity on DA with the presence of other human-related biofluids was also reported. These results show that f-MWCNT/AgNP nanocomposites are a promising biosensor material for the detection of DA. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"9 1","pages":"97 - 108"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87262007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1917837
Omer Sadak
Abstract A nanocomposite, rGO/AuNPs, was synthesized simultaneously using one-pot approach with gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) within gelatin which used as a reducing and stabilizing agent. Then, the fabricated nanocomposites were characterized by UV-Vis, transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The optimal nanocomposite was determined using electrochemical approaches. After facile and eco-friendly synthesis of rGO/AuNPs nanocomposites, it was used to fabricate the bioanode of enzymatic glucose biosensors. After drop-casting the nanocomposites on a screen-printed electrode (SPE), the glucose oxidase (GOx) was immobilized on the pre-treated SPE through a protein cross-linking approach using glutaraldehyde (GA) as a crosslinking reagent and 2,5-dihydroxybenzaldehyde (DHB) as a mediator to improve the electrochemical performance. Then, electrochemical performance of enzyme immobilized nanocomposites was studied using the potentiostat. The results demonstrate that the enzymatic biosensor made of rGO/AuNPs nanocomposites showed enhanced the sensitivity of selectivity for detection of glucose. Graphical Abstract
{"title":"One-pot scalable synthesis of rGO/AuNPs nanocomposite and its application in enzymatic glucose biosensor","authors":"Omer Sadak","doi":"10.1080/20550324.2021.1917837","DOIUrl":"https://doi.org/10.1080/20550324.2021.1917837","url":null,"abstract":"Abstract A nanocomposite, rGO/AuNPs, was synthesized simultaneously using one-pot approach with gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) within gelatin which used as a reducing and stabilizing agent. Then, the fabricated nanocomposites were characterized by UV-Vis, transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The optimal nanocomposite was determined using electrochemical approaches. After facile and eco-friendly synthesis of rGO/AuNPs nanocomposites, it was used to fabricate the bioanode of enzymatic glucose biosensors. After drop-casting the nanocomposites on a screen-printed electrode (SPE), the glucose oxidase (GOx) was immobilized on the pre-treated SPE through a protein cross-linking approach using glutaraldehyde (GA) as a crosslinking reagent and 2,5-dihydroxybenzaldehyde (DHB) as a mediator to improve the electrochemical performance. Then, electrochemical performance of enzyme immobilized nanocomposites was studied using the potentiostat. The results demonstrate that the enzymatic biosensor made of rGO/AuNPs nanocomposites showed enhanced the sensitivity of selectivity for detection of glucose. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"303 1","pages":"44 - 52"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77212596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1977063
Ahmad M. Al-Diabat, Natheer A. Algadri, N. M. Ahmed, A. Abuelsamen, S. A. Bidier
Abstract In this study, an inexpensive simple method for the fabrication of efficient hydrogen (H2) gas sensor based on carbon nanotubes (CNTs) was presented. The CNTs were synthesized using microwave oven and deposited onto SiO2 substrate by a dielectrophoretic method. The as-grown CNTs showed an n-type behavior because CNTs possess the characters of both metallic and semiconductor when placed between the two electrodes, meanwhile, the current was directed mostly by metallic tubes. Upon exposure to H2 gas at room temperature, the CNTs exhibited high sensitivity up to 315% at 140 ppm H2, and relatively good sensitivity of 40% at a very low H2 gas concentration of 20 ppm. To the best of our knowledge, this is the first work involving the fabrication of CNTs for detecting a low H2 gas concentration of 20 ppm at RT with high sensitivity comparing with other previous studies. Graphical Abstract
{"title":"A high-sensitivity hydrogen gas sensor based on carbon nanotubes fabricated on SiO2 substrate","authors":"Ahmad M. Al-Diabat, Natheer A. Algadri, N. M. Ahmed, A. Abuelsamen, S. A. Bidier","doi":"10.1080/20550324.2021.1977063","DOIUrl":"https://doi.org/10.1080/20550324.2021.1977063","url":null,"abstract":"Abstract In this study, an inexpensive simple method for the fabrication of efficient hydrogen (H2) gas sensor based on carbon nanotubes (CNTs) was presented. The CNTs were synthesized using microwave oven and deposited onto SiO2 substrate by a dielectrophoretic method. The as-grown CNTs showed an n-type behavior because CNTs possess the characters of both metallic and semiconductor when placed between the two electrodes, meanwhile, the current was directed mostly by metallic tubes. Upon exposure to H2 gas at room temperature, the CNTs exhibited high sensitivity up to 315% at 140 ppm H2, and relatively good sensitivity of 40% at a very low H2 gas concentration of 20 ppm. To the best of our knowledge, this is the first work involving the fabrication of CNTs for detecting a low H2 gas concentration of 20 ppm at RT with high sensitivity comparing with other previous studies. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"1 1","pages":"172 - 183"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90480019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1942641
S. Chanda, D. Bajwa, G. Holt, N. Stark, S. Bajwa, M. Quadir
Abstract Cellulose nanocrystal (CNC) has potential to be used as a reinforcement in polymeric nanocomposites because of their inherent biodegradability, universal accessibility, and superior mechanical properties. The most crucial challenge faced in the nanocomposite production is dispersing the nanoparticles effectively in the polymer matrix, so that the exceptional mechanical properties of the nanoparticles can be transferred to the macroscale properties to the bulk nanocomposites. In this research, a safe, effective and ecofriendly modification was used to functionalize the surface hydroxyl groups of CNC via silane treatment. These modified CNCs were used as reinforcements to prepare poly (ethylene oxide) (PEO)/CNC nanocomposites. The composites were prepared using solvent casting method. The composite properties were evaluated using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). The SEM micrographs demonstrated that the composites incorporated with silane treated CNCs showed improvement in the dispersion behavior of the nanoparticles in the matrix. Oxidative combustion of the composites containing silane treated CNCs promoted char formation and enhanced thermal stability. The composites containing (1:1) silane treated CNCs exhibited the better crystallization ability, highest storage modulus, and lowest tan δ value compared to the other silane treated systems indicating improved dispersion of CNC. The polysiloxane network provided an efficient surface covering of the CNC molecules, imparting reduced polar surface characteristics and enhancing the overall mechanical properties of the composites. Graphical Abstract
{"title":"Silane compatibilzation to improve the dispersion, thermal and mechancial properties of cellulose nanocrystals in poly (ethylene oxide)","authors":"S. Chanda, D. Bajwa, G. Holt, N. Stark, S. Bajwa, M. Quadir","doi":"10.1080/20550324.2021.1942641","DOIUrl":"https://doi.org/10.1080/20550324.2021.1942641","url":null,"abstract":"Abstract Cellulose nanocrystal (CNC) has potential to be used as a reinforcement in polymeric nanocomposites because of their inherent biodegradability, universal accessibility, and superior mechanical properties. The most crucial challenge faced in the nanocomposite production is dispersing the nanoparticles effectively in the polymer matrix, so that the exceptional mechanical properties of the nanoparticles can be transferred to the macroscale properties to the bulk nanocomposites. In this research, a safe, effective and ecofriendly modification was used to functionalize the surface hydroxyl groups of CNC via silane treatment. These modified CNCs were used as reinforcements to prepare poly (ethylene oxide) (PEO)/CNC nanocomposites. The composites were prepared using solvent casting method. The composite properties were evaluated using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). The SEM micrographs demonstrated that the composites incorporated with silane treated CNCs showed improvement in the dispersion behavior of the nanoparticles in the matrix. Oxidative combustion of the composites containing silane treated CNCs promoted char formation and enhanced thermal stability. The composites containing (1:1) silane treated CNCs exhibited the better crystallization ability, highest storage modulus, and lowest tan δ value compared to the other silane treated systems indicating improved dispersion of CNC. The polysiloxane network provided an efficient surface covering of the CNC molecules, imparting reduced polar surface characteristics and enhancing the overall mechanical properties of the composites. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"105 1","pages":"87 - 96"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78088555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1972690
Duc-Binh Nguyen, N. T. Van, T. Nguyen, V. Vuong, D. Lai, M. T. Phong, T. Le
Abstract Nylon 66, which is an important membrane class used in manufacturing of chitin and chitosan, have a number of features that can be improved by surface functionalizations into a novel composite structure with support of ultrasound and silica gel (SiG) catalyst in a doubled amidation reaction. Firstly, nylon 66/para-phenylenediamine thin film composite (NP-TFC) is prepared from commercial nylon 66 membrane in an ultrasound assisted hydrolysis-amidation reaction. Secondly, carboxylic functionalized multi-walled carbon nanotubes (MWCNT-COOH) are grafted on the NP fiber in an ultrasound assisted/SiG-catalyzed amidation reaction, where para-phenylenediamine (pPD) role is cross-linking. As an excellent result confirmed by either Fourier transform infrared (FTIR), Raman spectrometry or scanning electron microscopic (SEM), bundled MWCNTs bridges are easily built in SiG-catalyzed ethanol media to connect nylon 66 fibers at distances of 0.3–1 μm. The vacuum filtration test confirmed that as-prepared nylon 66/pPD/MWCNTs structure has superior Ca2+ rejection efficiency to that of original nylon 66. Graphical Abstract
{"title":"Surface functionalization of nylon 66 membrane using para-phenylenediamine and carboxylic functionalized multi-walled carbon nanotubes for removal of calcium ions from aqueous solution","authors":"Duc-Binh Nguyen, N. T. Van, T. Nguyen, V. Vuong, D. Lai, M. T. Phong, T. Le","doi":"10.1080/20550324.2021.1972690","DOIUrl":"https://doi.org/10.1080/20550324.2021.1972690","url":null,"abstract":"Abstract Nylon 66, which is an important membrane class used in manufacturing of chitin and chitosan, have a number of features that can be improved by surface functionalizations into a novel composite structure with support of ultrasound and silica gel (SiG) catalyst in a doubled amidation reaction. Firstly, nylon 66/para-phenylenediamine thin film composite (NP-TFC) is prepared from commercial nylon 66 membrane in an ultrasound assisted hydrolysis-amidation reaction. Secondly, carboxylic functionalized multi-walled carbon nanotubes (MWCNT-COOH) are grafted on the NP fiber in an ultrasound assisted/SiG-catalyzed amidation reaction, where para-phenylenediamine (pPD) role is cross-linking. As an excellent result confirmed by either Fourier transform infrared (FTIR), Raman spectrometry or scanning electron microscopic (SEM), bundled MWCNTs bridges are easily built in SiG-catalyzed ethanol media to connect nylon 66 fibers at distances of 0.3–1 μm. The vacuum filtration test confirmed that as-prepared nylon 66/pPD/MWCNTs structure has superior Ca2+ rejection efficiency to that of original nylon 66. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"69 1","pages":"160 - 171"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74772477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/20550324.2021.1961507
G. Tefera, G. Bright, S. Adali
Abstract This study focuses on mechanical characterization of carbon fiber reinforced polymer (CFRP) laminates reinforced with non-treated and treated multiwalled carbon nanotubes (CNTs) using nitric acid. The CNTs were treated using nitric acid to obtain carboxylic functional group. The epoxy resins are mixed with 0.3%wt of multiwalled CNTs at a constant mixing speed of 2000 rpm and mixing times varied from 24 to 96 h. Laminates reinforced with treated multiwalled CNTs show an increase in the flexural strength by 17.4 and 15.3% at mixing times of 24 and 96 h as compared to control laminates. The test results indicated that laminates reinforced with treated multiwalled CNTs have improved interlaminar shear failure stress which is 14 and 7% higher at mixing times of 24 and 96 h as compared to control specimen. Improvement in behavior was achieved for functionalized CNTs based laminates which prevents agglomeration. Longer mixing time (96 h) is not beneficial for enhancing the mechanical properties due to the break-up of small aggregates by overcoming the effect of van der Waals forces. Graphical Abstract
{"title":"Flexural and shear properties of CFRP laminates reinforced with functionalized multiwalled CNTs","authors":"G. Tefera, G. Bright, S. Adali","doi":"10.1080/20550324.2021.1961507","DOIUrl":"https://doi.org/10.1080/20550324.2021.1961507","url":null,"abstract":"Abstract This study focuses on mechanical characterization of carbon fiber reinforced polymer (CFRP) laminates reinforced with non-treated and treated multiwalled carbon nanotubes (CNTs) using nitric acid. The CNTs were treated using nitric acid to obtain carboxylic functional group. The epoxy resins are mixed with 0.3%wt of multiwalled CNTs at a constant mixing speed of 2000 rpm and mixing times varied from 24 to 96 h. Laminates reinforced with treated multiwalled CNTs show an increase in the flexural strength by 17.4 and 15.3% at mixing times of 24 and 96 h as compared to control laminates. The test results indicated that laminates reinforced with treated multiwalled CNTs have improved interlaminar shear failure stress which is 14 and 7% higher at mixing times of 24 and 96 h as compared to control specimen. Improvement in behavior was achieved for functionalized CNTs based laminates which prevents agglomeration. Longer mixing time (96 h) is not beneficial for enhancing the mechanical properties due to the break-up of small aggregates by overcoming the effect of van der Waals forces. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"15 1","pages":"141 - 153"},"PeriodicalIF":4.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83625458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-29DOI: 10.1080/20550324.2020.1857121
Xi Zhang, Xuetao Shi, J. Gautrot, T. Peijs
Abstract Electrospun fibers have received significant interests for various application areas such as filtration, composites and biomedical products due to their large surface area, good continuity, high porosity and many other unique properties. In bio-related applications, electrospun fibers have been used for in-situ drug delivery, tissue engineering scaffolds and wound dressing. In more recent years, there has been a drive toward novel electrospun fibers with added functionalities. Nanoengineering of electrospun fibers has introduced many of such novel properties. Through this review, researchers are provided with a state of the art overview of nanoenhanced electrospun fibers with added functionalities. Examples of some nanoengineered fibers include; surface functionalization, multi-component fibers, porous nanofibers, the creation of surface nano-topographies, and the incorporation of nanoparticles to create hierarchical fibrous structures for tailoring of physicochemical properties with a special focus on biomedical applications. Graphical Abstract
{"title":"Nanoengineered electrospun fibers and their biomedical applications: a review","authors":"Xi Zhang, Xuetao Shi, J. Gautrot, T. Peijs","doi":"10.1080/20550324.2020.1857121","DOIUrl":"https://doi.org/10.1080/20550324.2020.1857121","url":null,"abstract":"Abstract Electrospun fibers have received significant interests for various application areas such as filtration, composites and biomedical products due to their large surface area, good continuity, high porosity and many other unique properties. In bio-related applications, electrospun fibers have been used for in-situ drug delivery, tissue engineering scaffolds and wound dressing. In more recent years, there has been a drive toward novel electrospun fibers with added functionalities. Nanoengineering of electrospun fibers has introduced many of such novel properties. Through this review, researchers are provided with a state of the art overview of nanoenhanced electrospun fibers with added functionalities. Examples of some nanoengineered fibers include; surface functionalization, multi-component fibers, porous nanofibers, the creation of surface nano-topographies, and the incorporation of nanoparticles to create hierarchical fibrous structures for tailoring of physicochemical properties with a special focus on biomedical applications. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"6 1","pages":"1 - 34"},"PeriodicalIF":4.6,"publicationDate":"2020-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81564653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.1080/20550324.2020.1865712
Iman Ahmed Younus, A. Ezzat, M. Uonis
Abstract Chemical bath deposition was used to prepare thin films of ZnTe. The density of compounds (0.5–2) ml in 50 ml of distilled water, the precipitation time (10–80 min), and the solution temperature during the precipitation process (15–85 °C) have been changed during the preparation of the ZnTe thin films to get the optimal deposition conditions of a semiconductor. The effect of these parameters has been determined by studying the optical properties of the films which included the transmittance and absorbance as a function of the wavelength and energy gap. The energy gap remains constant at about 2.7 eV over all precipitation times for each density of compound. We have also found that the energy gap of the films decreases with increasing solution temperature, reaching approximately 2.9-3eV at 15 °C and decreasing to 2.4 eV at 85 °C. Graphical Abstract
{"title":"Preparation of ZnTe thin films using chemical bath deposition technique","authors":"Iman Ahmed Younus, A. Ezzat, M. Uonis","doi":"10.1080/20550324.2020.1865712","DOIUrl":"https://doi.org/10.1080/20550324.2020.1865712","url":null,"abstract":"Abstract Chemical bath deposition was used to prepare thin films of ZnTe. The density of compounds (0.5–2) ml in 50 ml of distilled water, the precipitation time (10–80 min), and the solution temperature during the precipitation process (15–85 °C) have been changed during the preparation of the ZnTe thin films to get the optimal deposition conditions of a semiconductor. The effect of these parameters has been determined by studying the optical properties of the films which included the transmittance and absorbance as a function of the wavelength and energy gap. The energy gap remains constant at about 2.7 eV over all precipitation times for each density of compound. We have also found that the energy gap of the films decreases with increasing solution temperature, reaching approximately 2.9-3eV at 15 °C and decreasing to 2.4 eV at 85 °C. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"1 1","pages":"165 - 172"},"PeriodicalIF":4.6,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88463337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-18DOI: 10.1080/20550324.2020.1865711
M. Bansal, D. Ahlawat, Amrik Singh, Vijay Kumar, S. P. Rathee
Abstract Silica coated cobalt ferrite (CoFe2O4:SiO2) nanocomposites were synthesized by co-precipitation technique using metal nitrates as precursors. The as-prepared samples were heat treated at different temperatures of 250, 500 and 750 °C for 24 h. Structural, thermal, and morphological behavior of nanocomposites are investigated by XRD, FTIR, TGA-DTG, and SEM characterization results, useful in biomedical applications. With increasing calcinations temperature from 250 to 500 °C and 750 °C an increase in crystallite size of CoFe2O4:SiO2 nanocomposites has been determined from 20.26 to 28.95 nm and 38.76 nm by Williamson–Hall method, respectively. Furthermore, by increasing the temperature from 250 to 750 °C the lattice parameter and strain values have been found to increase from 8.0321 to 8.0691 Å and 1.01 × 10−2 to 3.75 × 10−3, respectively. Analysis of TGA results found no weight loss when the sample was heated beyond 700 °C and thus complete decomposition of precursors has led to the formation of stable nanocomposite structures at high temperatures. SEM analysis of synthesized samples at 750 °C revealed well developed nanoparticles of CoFe2O4: SiO2 with inter-granular porosity. Graphical Abstract
{"title":"Effect of heat treatment on the microstructural properties of silica embedded cobalt ferrite nanocomposites","authors":"M. Bansal, D. Ahlawat, Amrik Singh, Vijay Kumar, S. P. Rathee","doi":"10.1080/20550324.2020.1865711","DOIUrl":"https://doi.org/10.1080/20550324.2020.1865711","url":null,"abstract":"Abstract Silica coated cobalt ferrite (CoFe2O4:SiO2) nanocomposites were synthesized by co-precipitation technique using metal nitrates as precursors. The as-prepared samples were heat treated at different temperatures of 250, 500 and 750 °C for 24 h. Structural, thermal, and morphological behavior of nanocomposites are investigated by XRD, FTIR, TGA-DTG, and SEM characterization results, useful in biomedical applications. With increasing calcinations temperature from 250 to 500 °C and 750 °C an increase in crystallite size of CoFe2O4:SiO2 nanocomposites has been determined from 20.26 to 28.95 nm and 38.76 nm by Williamson–Hall method, respectively. Furthermore, by increasing the temperature from 250 to 750 °C the lattice parameter and strain values have been found to increase from 8.0321 to 8.0691 Å and 1.01 × 10−2 to 3.75 × 10−3, respectively. Analysis of TGA results found no weight loss when the sample was heated beyond 700 °C and thus complete decomposition of precursors has led to the formation of stable nanocomposite structures at high temperatures. SEM analysis of synthesized samples at 750 °C revealed well developed nanoparticles of CoFe2O4: SiO2 with inter-granular porosity. Graphical Abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"62 1","pages":"158 - 164"},"PeriodicalIF":4.6,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77908047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1080/20550324.2020.1858246
J. Safaei‐Ghomi, Ali Kareem Abbas, Marzieh Shahpiri
Abstract H3PW12O40-amino-functionalized CdFe12O19@SiO2 nanocomposite has been applied as an effective nanocatalyst for the preparation of imidazoles by three-component reactions of benzil, ammonium acetate, and benzaldehydes under solvent-free condition. H3PW12O40-amino-functionalized CdFe12O19@SiO2 nanocomposites has been identified by powder X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometer, thermal gravimetric analysis, and Fourier transform infrared spectroscopy. This method provides several benefits including easy work-up, the use solvent-free conditions, the low catalyst loading and the reusability of the catalyst. Recently the use of environmental and green catalysts which can be easily recycled has received significant attention. Besides environmental advantages, such recoverable catalysts can also provide a platform for heterogeneous catalysis, green chemistry, and environmentally benign protocols in the near future. Graphical abstract
{"title":"Synthesis of imidazoles promoted by H3PW12O40-amino-functionalized CdFe12O19@SiO2 nanocomposite","authors":"J. Safaei‐Ghomi, Ali Kareem Abbas, Marzieh Shahpiri","doi":"10.1080/20550324.2020.1858246","DOIUrl":"https://doi.org/10.1080/20550324.2020.1858246","url":null,"abstract":"Abstract H3PW12O40-amino-functionalized CdFe12O19@SiO2 nanocomposite has been applied as an effective nanocatalyst for the preparation of imidazoles by three-component reactions of benzil, ammonium acetate, and benzaldehydes under solvent-free condition. H3PW12O40-amino-functionalized CdFe12O19@SiO2 nanocomposites has been identified by powder X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometer, thermal gravimetric analysis, and Fourier transform infrared spectroscopy. This method provides several benefits including easy work-up, the use solvent-free conditions, the low catalyst loading and the reusability of the catalyst. Recently the use of environmental and green catalysts which can be easily recycled has received significant attention. Besides environmental advantages, such recoverable catalysts can also provide a platform for heterogeneous catalysis, green chemistry, and environmentally benign protocols in the near future. Graphical abstract","PeriodicalId":18872,"journal":{"name":"Nanocomposites","volume":"58 1","pages":"149 - 157"},"PeriodicalIF":4.6,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80721073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：