Pub Date : 2022-03-31DOI: 10.47363/jmsmr/2022(3)123
J. A. Adem, John Agumba, G. Barasa, A. A. Ochung
In this study, the fingerprint of the acid concentration during the hydrolysis process on the optical band gap of cellulose nanocrystals (CNCs) has been systematically studied. The CNCs have been prepared using hydrochloric acid at a hydrolysis temperature of 50°C and at a constant hydrolysis time of 4 hours but with varying hydrochloric cid concentrations of 5%, 10% and 15%. The crystalline structure and phase identification of the CNCs have been studied using XRD technique. UV-Vis Spectroscopy has been done and the optical band gap energy calculated by performing the Tauc’s plot. From the study, the grain size has been found to decrease with acid concentration while the band gap energy has been found to increase with increasing acid concentration. Further, the optical band gaps of the CNCs have been found to decrease with the increase in crystallite size. This shrinkage of the band gap has been attributed to the increased impurity concentration leading to the narrowing of the band gap due to the emerging of the impurity band formed by the overlapped impurity states
{"title":"The Role of Acid Concentration on Band Gap Shrinkage in Cellulose Nanocrystals Fabricated from Water Hyacinth","authors":"J. A. Adem, John Agumba, G. Barasa, A. A. Ochung","doi":"10.47363/jmsmr/2022(3)123","DOIUrl":"https://doi.org/10.47363/jmsmr/2022(3)123","url":null,"abstract":"In this study, the fingerprint of the acid concentration during the hydrolysis process on the optical band gap of cellulose nanocrystals (CNCs) has been systematically studied. The CNCs have been prepared using hydrochloric acid at a hydrolysis temperature of 50°C and at a constant hydrolysis time of 4 hours but with varying hydrochloric cid concentrations of 5%, 10% and 15%. The crystalline structure and phase identification of the CNCs have been studied using XRD technique. UV-Vis Spectroscopy has been done and the optical band gap energy calculated by performing the Tauc’s plot. From the study, the grain size has been found to decrease with acid concentration while the band gap energy has been found to increase with increasing acid concentration. Further, the optical band gaps of the CNCs have been found to decrease with the increase in crystallite size. This shrinkage of the band gap has been attributed to the increased impurity concentration leading to the narrowing of the band gap due to the emerging of the impurity band formed by the overlapped impurity states","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83317848","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)119
H. Nadir, Ash Ahmed
Concrete is one of the most widely used construction material in the world which uses aggregates and cement as a binder. Use of cement concrete and mining/ transportation of raw materials makes the construction industry the biggest emitter of CO2 by contributing up to 7-10% of global emissions. The waste materials from different industries and agriculture contribute to 90% of waste disposal/ recycling effort in the world. This research has focused to use a selection of waste materials as supplementary cementitious materials (SCM) to minimize the emission of CO2 and recycling/ absorption of waste from other industries to construction industry to make it more sustainable. The contemporary research has established use of pulverized fly ash (PFA), silica fume (SF), metakaolin (MK) and granulated ground blast furnace slag (GGBS) as suitable SCMs. This study has focused on using two established industrial waste SF and MK and two agricultural wastes, rice husk ash (RHA) and palm ash (PA), to determine and compare their potential use as pozzolanic SCMs and to expand the family of alternative pozzolanic binders in addition to PFA and GGBS. The w/c (w/b) ratio was 0.4 with an intended design mix strength classification of C50/60. The chemical composition of all the materials was determined through x-ray spectrometry/ diffraction test to ascertain the chemistry. All four materials satisfied the ASTM constituent criteria for pozzolans. In comparison to the control mix (100% cement content), all these materials improved the compressive strength from 2.5% to 30% and enhanced tensile strength from up to 17%, indeed all the SCM mixes had a higher compressive strength than the control. RHA exhibited the best performance in agricultural waste with 10% optimum quantity to give maximum compressive strength of 83 MPa and PA exhibited the optimum performance with 2.5% content and gave maximum compressive strength of 78 MPa. The addition of MK progressively increased the compressive strength with 20% content mix giving a strength of 84 MPa. The SF performed the best at optimum quantity of 2.5% and exhibited the highest compressive strength of 90 MPa. The results suggest that these SCM based concrete are recommended for formulation of high-strength concrete applications, i.e., 60+ MPa. Furthermore, all the SCMs had at least one mix which satisfied the C60/75 classification without reducing the w/b ratio below 0.4; this has significant positive ramifications for the development of sustainable high-performance concrete. The absorption of waste materials from industrial and agricultural fields can substantially reduce waste disposal and more pertinently facilitate in reducing the CO2 emission associated with the construction industry
{"title":"Comparative Evaluation of Potential Impacts of Agricultural and Industrial Waste Pozzolanic Binders on Strengths of Concrete","authors":"H. Nadir, Ash Ahmed","doi":"10.47363/jmsmr/2021(2)119","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)119","url":null,"abstract":"Concrete is one of the most widely used construction material in the world which uses aggregates and cement as a binder. Use of cement concrete and mining/ transportation of raw materials makes the construction industry the biggest emitter of CO2 by contributing up to 7-10% of global emissions. The waste materials from different industries and agriculture contribute to 90% of waste disposal/ recycling effort in the world. This research has focused to use a selection of waste materials as supplementary cementitious materials (SCM) to minimize the emission of CO2 and recycling/ absorption of waste from other industries to construction industry to make it more sustainable. The contemporary research has established use of pulverized fly ash (PFA), silica fume (SF), metakaolin (MK) and granulated ground blast furnace slag (GGBS) as suitable SCMs. This study has focused on using two established industrial waste SF and MK and two agricultural wastes, rice husk ash (RHA) and palm ash (PA), to determine and compare their potential use as pozzolanic SCMs and to expand the family of alternative pozzolanic binders in addition to PFA and GGBS. The w/c (w/b) ratio was 0.4 with an intended design mix strength classification of C50/60. The chemical composition of all the materials was determined through x-ray spectrometry/ diffraction test to ascertain the chemistry. All four materials satisfied the ASTM constituent criteria for pozzolans. In comparison to the control mix (100% cement content), all these materials improved the compressive strength from 2.5% to 30% and enhanced tensile strength from up to 17%, indeed all the SCM mixes had a higher compressive strength than the control. RHA exhibited the best performance in agricultural waste with 10% optimum quantity to give maximum compressive strength of 83 MPa and PA exhibited the optimum performance with 2.5% content and gave maximum compressive strength of 78 MPa. The addition of MK progressively increased the compressive strength with 20% content mix giving a strength of 84 MPa. The SF performed the best at optimum quantity of 2.5% and exhibited the highest compressive strength of 90 MPa. The results suggest that these SCM based concrete are recommended for formulation of high-strength concrete applications, i.e., 60+ MPa. Furthermore, all the SCMs had at least one mix which satisfied the C60/75 classification without reducing the w/b ratio below 0.4; this has significant positive ramifications for the development of sustainable high-performance concrete. The absorption of waste materials from industrial and agricultural fields can substantially reduce waste disposal and more pertinently facilitate in reducing the CO2 emission associated with the construction industry","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73242840","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)121
Saurabh Rai, Kalyani Panigrahi
Tensile testing on metastable beta alloy with various microstructures was carried out in this study. Beta 21S is a metastable alloy that exhibits a wide range of material characteristics depending on the processing techniques used. Three different sheets that have been used in this paper which has the same substance but three different microstructures. At a strain rate of 0.001/s, the tensile test was done on a single sheet at five different temperatures. The sheet has developed varied microstructures, the tensile nature of the material varies the alloy’s characteristics. Mechanical characteristics for 400°C, 500°C, 600°C, and 7000°C are described for 21S sheets. The alpha phase sheet elongated at room temperature by 1-3 %, whereas the pure beta phase sheet elongated by 22-24 %. There is a significant improvement in the extension of the sheet with the variation in temperature for the alpha phase. The elongation of the pure beta phase does not alter as the temperature rises. The fracture surface was tested at all temperatures and the optimal temperature for forming the sheet has been determined
{"title":"Tensile Flow Behaviour and Fracture Studies of Beta Titanium Alloys at Elevated Temperatures","authors":"Saurabh Rai, Kalyani Panigrahi","doi":"10.47363/jmsmr/2021(2)121","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)121","url":null,"abstract":"Tensile testing on metastable beta alloy with various microstructures was carried out in this study. Beta 21S is a metastable alloy that exhibits a wide range of material characteristics depending on the processing techniques used. Three different sheets that have been used in this paper which has the same substance but three different microstructures. At a strain rate of 0.001/s, the tensile test was done on a single sheet at five different temperatures. The sheet has developed varied microstructures, the tensile nature of the material varies the alloy’s characteristics. Mechanical characteristics for 400°C, 500°C, 600°C, and 7000°C are described for 21S sheets. The alpha phase sheet elongated at room temperature by 1-3 %, whereas the pure beta phase sheet elongated by 22-24 %. There is a significant improvement in the extension of the sheet with the variation in temperature for the alpha phase. The elongation of the pure beta phase does not alter as the temperature rises. The fracture surface was tested at all temperatures and the optimal temperature for forming the sheet has been determined","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82835005","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)116
JS Kwame, E. Yakushina, P. Blackwell
Post-manufacturing induced defects in the form of scratches are sometimes inadvertently introduced onto sheet metal surfaces during either transportation, storage or handling. However, limited research has been previously carried out to establish the impact of such surface defects on sheet formability. Test trial results after press brake forming of Ti-3Al-2.5V showed that for longitudinal scratches oriented along the sheet rolling direction, scratch profiles with depth in the ranges of -1μm to -18μm and pile up height between 1μm to 16μm can be successfully formed; hence could be deemed acceptable during the sheet selection process. Failure of the coupons during the press brake forming trials was due to the impact of the scratch defects in their role as stress raisers and occurred primarily at the longitudinal scratch defect zones
{"title":"Influence of Longitudinal Scratch Defects on the Bendability of Titanium Alloy","authors":"JS Kwame, E. Yakushina, P. Blackwell","doi":"10.47363/jmsmr/2021(2)116","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)116","url":null,"abstract":"Post-manufacturing induced defects in the form of scratches are sometimes inadvertently introduced onto sheet metal surfaces during either transportation, storage or handling. However, limited research has been previously carried out to establish the impact of such surface defects on sheet formability. Test trial results after press brake forming of Ti-3Al-2.5V showed that for longitudinal scratches oriented along the sheet rolling direction, scratch profiles with depth in the ranges of -1μm to -18μm and pile up height between 1μm to 16μm can be successfully formed; hence could be deemed acceptable during the sheet selection process. Failure of the coupons during the press brake forming trials was due to the impact of the scratch defects in their role as stress raisers and occurred primarily at the longitudinal scratch defect zones","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86783091","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)120
Bahman Zohuri, Masoud Moghaddam
Aftermath of “Havana Syndrome” that took place in Cuba, at around 2016 – 2017 time-frame, where American diplomat got mysterious sickness, the dawn of a new military age was born, where directed energy weapons in form waves are now in play. Among concerned government agencies, they still cannot find the source of the sickness except, stating that whatever was the cause, it is unnatural source, but rather man-made weapons in form of high microwave beam weapon. However, this author with this short review is going to show a different perspective of directed energy beam weapons, knowingly that this type weapons are not anything new and scientist and engineer, at national laboratories, department of energy and defense level including some universities nation-wide have been involved with research and development of such direct energy weapons. The battles of tomorrow are not going to take place with speed of bullet or artillery shell, but rather will be fought with speed of light and electron, and that is why the new military age presents itself along with new innovative technologies that is discussed here in this short review. For purpose beam weapons as directed energy we are not taking under consideration, the high power energy laser, since it is beyond the scope of this short review, however we focus on wave frequencies that are falling within high power microwave bandwidth and we introduce another beam weapon’s concept that is known as scalar wave, which we know it as longitudinal scalar wave, that possibly can justify the above sickness caused by the unnatural source, which falls within a man-made source of energy that can travel long distance and penetrated even through Faraday’s cage and any other obstacle in front of very similar to behavior and characteristic of soliton wave. Whatever covert sound or high energy acoustic or wave weapon this man-made phenomena was or is will be discussed in this report with some means of science physics behind it. All scientific discussion in this short review is presentation of this author period
{"title":"Directed Energy Beam Weapons the Dawn of a New Military Age","authors":"Bahman Zohuri, Masoud Moghaddam","doi":"10.47363/jmsmr/2021(2)120","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)120","url":null,"abstract":"Aftermath of “Havana Syndrome” that took place in Cuba, at around 2016 – 2017 time-frame, where American diplomat got mysterious sickness, the dawn of a new military age was born, where directed energy weapons in form waves are now in play. Among concerned government agencies, they still cannot find the source of the sickness except, stating that whatever was the cause, it is unnatural source, but rather man-made weapons in form of high microwave beam weapon. However, this author with this short review is going to show a different perspective of directed energy beam weapons, knowingly that this type weapons are not anything new and scientist and engineer, at national laboratories, department of energy and defense level including some universities nation-wide have been involved with research and development of such direct energy weapons. The battles of tomorrow are not going to take place with speed of bullet or artillery shell, but rather will be fought with speed of light and electron, and that is why the new military age presents itself along with new innovative technologies that is discussed here in this short review. For purpose beam weapons as directed energy we are not taking under consideration, the high power energy laser, since it is beyond the scope of this short review, however we focus on wave frequencies that are falling within high power microwave bandwidth and we introduce another beam weapon’s concept that is known as scalar wave, which we know it as longitudinal scalar wave, that possibly can justify the above sickness caused by the unnatural source, which falls within a man-made source of energy that can travel long distance and penetrated even through Faraday’s cage and any other obstacle in front of very similar to behavior and characteristic of soliton wave. Whatever covert sound or high energy acoustic or wave weapon this man-made phenomena was or is will be discussed in this report with some means of science physics behind it. All scientific discussion in this short review is presentation of this author period","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84162474","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)122
Ramona Dogea, Xiuting Yan, R. Millar
Additive manufacturing has been adopted widely across various industries for producing parts mainly due to their ability to create complex geometries, eliminate material wastage and enable faster production rate, among others. Additive manufacturing has also increased design solution space by enabling exploration of mechatronic solutions for mechanical structures. This includes the integration of smart devices into wing structures to achieve a datadriven predictive maintenance-based system. For this, there is still the need to continuously explore various ways of integrating sensory capability into a mechanical structure during the manufacturing processes to ensure improvement and reliability of aircraft components. The scope of this paper was to analyse different wing rib geometries and the influence of embedding sensory capability via design for additive manufacturing process. In this work, three wing rib geometries with cut-outs and for sensory placement were designed and analysed to estimate their equivalent stress and deformation when such sensory locations are introduced. The results confirm the idea that it is feasible to introduce holding cavities for structural performance monitoring sensors without compromising the structural design requirements. The results also show that deformation and stress are highly dependent on the rib thickness and the insertion of sensory locations
{"title":"A Smart Wing Rib Structure Suitable for Design for Additive Manufacturing (DfAM) Process","authors":"Ramona Dogea, Xiuting Yan, R. Millar","doi":"10.47363/jmsmr/2021(2)122","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)122","url":null,"abstract":"Additive manufacturing has been adopted widely across various industries for producing parts mainly due to their ability to create complex geometries, eliminate material wastage and enable faster production rate, among others. Additive manufacturing has also increased design solution space by enabling exploration of mechatronic solutions for mechanical structures. This includes the integration of smart devices into wing structures to achieve a datadriven predictive maintenance-based system. For this, there is still the need to continuously explore various ways of integrating sensory capability into a mechanical structure during the manufacturing processes to ensure improvement and reliability of aircraft components. The scope of this paper was to analyse different wing rib geometries and the influence of embedding sensory capability via design for additive manufacturing process. In this work, three wing rib geometries with cut-outs and for sensory placement were designed and analysed to estimate their equivalent stress and deformation when such sensory locations are introduced. The results confirm the idea that it is feasible to introduce holding cavities for structural performance monitoring sensors without compromising the structural design requirements. The results also show that deformation and stress are highly dependent on the rib thickness and the insertion of sensory locations","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88474887","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 : 2021-12-31DOI: 10.47363/jmsmr/2021(2)118
Narottam Maity, S. Barik, P. K. Chaudhuri
The aim of the present article is to analyze the propagation of Rayleigh waves in a rotating fiber-reinforced electrically conducting elastic solid medium under the influence of surface stress, magnetic field and gravity. The magnetic field is applied in such a direction that the problem can be considered as a two dimensional one. The wave velocity equation for Rayleigh waves has been obtained. In the absence of gravity field, surface stress, rotation and fiberreinforcement, the frequency equation is in complete agreement with the corresponding classical results. The effects on various subjects of interest are discussed and shown graphically. Comparisons are made with the corresponding results in absence of surface stress
{"title":"Rayleigh-Type Waves in a Rotating Fiber-Reinforced Half Space under the Action of Magnetic Field, Gravity and Surface Stress","authors":"Narottam Maity, S. Barik, P. K. Chaudhuri","doi":"10.47363/jmsmr/2021(2)118","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)118","url":null,"abstract":"The aim of the present article is to analyze the propagation of Rayleigh waves in a rotating fiber-reinforced electrically conducting elastic solid medium under the influence of surface stress, magnetic field and gravity. The magnetic field is applied in such a direction that the problem can be considered as a two dimensional one. The wave velocity equation for Rayleigh waves has been obtained. In the absence of gravity field, surface stress, rotation and fiberreinforcement, the frequency equation is in complete agreement with the corresponding classical results. The effects on various subjects of interest are discussed and shown graphically. Comparisons are made with the corresponding results in absence of surface stress","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88641568","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 : 2021-08-12DOI: 10.47363/jmsmr/2021(2)117
Henadzi Filipenka
This article presents views on the classification of all known chemical elements, those fundamental components that make up the Earth and the entire Universe.
这篇文章提出了对所有已知化学元素的分类的看法，这些基本成分构成了地球和整个宇宙。
{"title":"Table of Chemical Elements Constructed According to the Charges of Atomic Nuclei","authors":"Henadzi Filipenka","doi":"10.47363/jmsmr/2021(2)117","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)117","url":null,"abstract":"This article presents views on the classification of all known chemical elements, those fundamental components that make up the Earth and the entire Universe.","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86370771","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 : 2021-06-30DOI: 10.47363/jmsmr/2021(2)115
F. Nasirov
Sustainable development, the design of green and economically feasible processes to produce synthetic polymers is one of the major needs and biggest challenges. Catalysis of polymerization processes is among the most important applications within the field of nanoscience. Intensive research is being conducted and considerable success has been achieved in the heterogenization of various homogeneous catalysts on nano supports for polymerization of olefins and dienes. The large surface area of various nanomaterials qualifies them quite naturally to act either as a heterogeneous promoter for catalytic reactions or as a support for the heterogenization of homogeneous catalysts. To the polymerization of olefins and dienes by using nanocatalysts are devoted significant numbers of published papers, but to elucidate the possible effect of both the type and properties of nano supports and their sizes and amounts on the activity and stereoselectivity of heterogenized catalysts and the properties of the obtained polymers are needed more detailed studies. This review attempted to collect some published research materials in the field of the nanocatalysis of olefins and dienes polymerization processes and our main aim is to assess the critical points and to indicate the future perspectives and possible strategies in this area of research. We are confident that this review will be a helpful companion and deliver key hints to those, in academia and in the industry, who decide to move their research interest in this direction
{"title":"Nanocatalysts in Olefins and Dienes Polymerization Processes","authors":"F. Nasirov","doi":"10.47363/jmsmr/2021(2)115","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)115","url":null,"abstract":"Sustainable development, the design of green and economically feasible processes to produce synthetic polymers is one of the major needs and biggest challenges. Catalysis of polymerization processes is among the most important applications within the field of nanoscience. Intensive research is being conducted and considerable success has been achieved in the heterogenization of various homogeneous catalysts on nano supports for polymerization of olefins and dienes. The large surface area of various nanomaterials qualifies them quite naturally to act either as a heterogeneous promoter for catalytic reactions or as a support for the heterogenization of homogeneous catalysts. To the polymerization of olefins and dienes by using nanocatalysts are devoted significant numbers of published papers, but to elucidate the possible effect of both the type and properties of nano supports and their sizes and amounts on the activity and stereoselectivity of heterogenized catalysts and the properties of the obtained polymers are needed more detailed studies. This review attempted to collect some published research materials in the field of the nanocatalysis of olefins and dienes polymerization processes and our main aim is to assess the critical points and to indicate the future perspectives and possible strategies in this area of research. We are confident that this review will be a helpful companion and deliver key hints to those, in academia and in the industry, who decide to move their research interest in this direction","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82787216","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 : 2021-06-30DOI: 10.47363/jmsmr/2021(2)112
Solomon L. Joseph, Agumba O. John, F. M. Keheze
Carbon nanomaterials have recently attracted wide scientific applications due to their tunable properties. These novel materials act as best fillers that can provide substantial benefits due to their high strength, thermal conductivity, and electrical conductivities. With their huge applications as bulk materials, when implemented in polymer matrix as fillers, they give rise to new promising materials with which their properties can be tuned to suit a particular application. Besides the development of these new nanocomposite materials, there exist some challenges which must be fully surpassed to explore the potentiality of application of carbon-based nanocomposites. Reduced graphene oxide is one of the carbon derivatives which has attracted the current advancement in technology, and recently, it found its new applications in super capacitors used in electronic industries. The limiting factor for its exploration is the affordability. New and affordable sources of these graphene-based nanomaterial have to be devised, for fully realization of their potential applications. In this study, reduced graphene oxide and the bio-polymer chitosan were extracted from the locally available bio waste materials. Nanocomposites were prepared at 50% rGO: chitosan ratio. The films were then prepared by spin coating method. Prepared films were subjected to morphological analysis. From the results, it was observed that rGO induced chitosan crystallization, which led to formation of dendritic structures. Cellulose nanocrystals have thus displayed temperature dependent positive uniaxial birefringence
{"title":"The Role of Bio-Extracted Reduced Graphene Oxide in the Crystallization Kinetics of Chitosan Bio-Polymer","authors":"Solomon L. Joseph, Agumba O. John, F. M. Keheze","doi":"10.47363/jmsmr/2021(2)112","DOIUrl":"https://doi.org/10.47363/jmsmr/2021(2)112","url":null,"abstract":"Carbon nanomaterials have recently attracted wide scientific applications due to their tunable properties. These novel materials act as best fillers that can provide substantial benefits due to their high strength, thermal conductivity, and electrical conductivities. With their huge applications as bulk materials, when implemented in polymer matrix as fillers, they give rise to new promising materials with which their properties can be tuned to suit a particular application. Besides the development of these new nanocomposite materials, there exist some challenges which must be fully surpassed to explore the potentiality of application of carbon-based nanocomposites. Reduced graphene oxide is one of the carbon derivatives which has attracted the current advancement in technology, and recently, it found its new applications in super capacitors used in electronic industries. The limiting factor for its exploration is the affordability. New and affordable sources of these graphene-based nanomaterial have to be devised, for fully realization of their potential applications. In this study, reduced graphene oxide and the bio-polymer chitosan were extracted from the locally available bio waste materials. Nanocomposites were prepared at 50% rGO: chitosan ratio. The films were then prepared by spin coating method. Prepared films were subjected to morphological analysis. From the results, it was observed that rGO induced chitosan crystallization, which led to formation of dendritic structures. Cellulose nanocrystals have thus displayed temperature dependent positive uniaxial birefringence","PeriodicalId":16328,"journal":{"name":"Journal of Material Sciences & Manufacturing Research","volume":"150 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74908599","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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