Pub Date : 2024-10-04DOI: 10.1007/s13367-024-00109-x
Kwang Soo Cho
Doi suggested a way to apply the Onsager variational principle to various complex fluids. However, since the Onsager principle is constructed by a daring generalization of classical irreversible thermodynamics (linear theory of fluxes and forces) in an inductive manner, it is questionable whether it can be applied to complex fluids which need non-classical state variables, which may called internal variables, and may require nonlinear relations between fluxes and forces. Since Doi’s approach is based on isothermal process and the stress formula which is defined from an analogy to an approximate equation for creeping flow, it is restricted to incompressible fluid. Our variational thermodynamics derives the Onsager variational principle in a deductive manner and removes the demerits of the Doi’s application of the Onsager variational principle. Our theory allows that regardless of the user's expertise, simply selecting state variables can automatically determine the arguments of the dissipation function and find the desired constitutive equations.
{"title":"Comparison of methodologies for the application of the Onsager variational principle","authors":"Kwang Soo Cho","doi":"10.1007/s13367-024-00109-x","DOIUrl":"10.1007/s13367-024-00109-x","url":null,"abstract":"<p>Doi suggested a way to apply the Onsager variational principle to various complex fluids. However, since the Onsager principle is constructed by a daring generalization of classical irreversible thermodynamics (linear theory of fluxes and forces) in an inductive manner, it is questionable whether it can be applied to complex fluids which need non-classical state variables, which may called internal variables, and may require nonlinear relations between fluxes and forces. Since Doi’s approach is based on isothermal process and the stress formula which is defined from an analogy to an approximate equation for creeping flow, it is restricted to incompressible fluid. Our variational thermodynamics derives the Onsager variational principle in a deductive manner and removes the demerits of the Doi’s application of the Onsager variational principle. Our theory allows that regardless of the user's expertise, simply selecting state variables can automatically determine the arguments of the dissipation function and find the desired constitutive equations.</p>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"37 1","pages":"43 - 55"},"PeriodicalIF":2.2,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1007/s13367-024-00108-y
Juri Kim, Eun Hui Jeong, Joon Hyun Baik, Jun Dong Park
Since the dawn of human civilization, cosmetics have been an important part of life for various reasons, including aesthetic purposes, skin protection, and representing social status and ideology for social and political reasons. Nowadays, due to advances in science and technology, cosmetics comes in countless distinctive formulations, each tailored to specific purposes and preferences. Rheology has been an essential tool in designing and analyzing complex cosmetic formulations, because of inherent characteristics of their usage, which inevitably involves processes of flow and deformation. Typically, the sensory texture of cosmetic formulations has been correlated with rheological measurements. Furthermore, because the physical and chemical properties, as well as the microstructural status of cosmetic formulations, are well reflected in their rheological behavior, rheology has proven to be an effective metric for assessing stability. This review aims to provide a structured overview of how rheology has been utilized in the cosmetics field and highlight its advancements. We specifically focus on the role of rheology in analyzing the sensory texture and stability in cosmetic formulations, emphasizing a variety of previous studies. In the last part, we present latest applications of rheological analysis combined with other modern techniques, including artificial intelligence and eco-friendly technologies.
{"title":"The role of rheology in cosmetics research: a review","authors":"Juri Kim, Eun Hui Jeong, Joon Hyun Baik, Jun Dong Park","doi":"10.1007/s13367-024-00108-y","DOIUrl":"10.1007/s13367-024-00108-y","url":null,"abstract":"<div><p>Since the dawn of human civilization, cosmetics have been an important part of life for various reasons, including aesthetic purposes, skin protection, and representing social status and ideology for social and political reasons. Nowadays, due to advances in science and technology, cosmetics comes in countless distinctive formulations, each tailored to specific purposes and preferences. Rheology has been an essential tool in designing and analyzing complex cosmetic formulations, because of inherent characteristics of their usage, which inevitably involves processes of flow and deformation. Typically, the sensory texture of cosmetic formulations has been correlated with rheological measurements. Furthermore, because the physical and chemical properties, as well as the microstructural status of cosmetic formulations, are well reflected in their rheological behavior, rheology has proven to be an effective metric for assessing stability. This review aims to provide a structured overview of how rheology has been utilized in the cosmetics field and highlight its advancements. We specifically focus on the role of rheology in analyzing the sensory texture and stability in cosmetic formulations, emphasizing a variety of previous studies. In the last part, we present latest applications of rheological analysis combined with other modern techniques, including artificial intelligence and eco-friendly technologies.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"271 - 282"},"PeriodicalIF":2.2,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1007/s13367-024-00110-4
Yuya Doi
Polymer architecture (i.e., chain connecting manner) and properties are closely correlate, and strongly influence rheological properties that reflect microscopic molecular dynamics. This review summarizes the rheological properties of ring polymers and polymers containing intramolecular loops, which are currently being studied actively in terms of sample synthesis and physical property. The ring polymers, which have a well-defined molecular architecture and free of impurities, exhibit rheological properties that differ significantly from those of their linear counterparts. Notably, even minor contamination with linear chain impurities is known to substantially alter the rheological properties of ring polymers. Theoretical molecular modeling studies are being pursed to elucidate these behaviors. The ring polymer analogues consisting of multiple ring chains or intramolecular linkages between ring and linear chains exhibit either unentangled or intermolecular penetration behavior, depending on their molecular architectures. The polymers featuring intrinsically random intramolecular loops, such as single-chain polymeric nanoparticles (SCNPs) and polymeric nanosheets, are also under active investigation in terms of both their synthesis and properties. A deeper understanding of the molecular dynamics and rheological properties of these unique architectural polymers can contribute to the further development of polymer science and industry as well as to the creation of new polymeric nano-materials.
{"title":"A review of rheology for ring polymers and polymers with internal loops: comparison of recent experimental and theoretical studies","authors":"Yuya Doi","doi":"10.1007/s13367-024-00110-4","DOIUrl":"10.1007/s13367-024-00110-4","url":null,"abstract":"<div><p>Polymer architecture (i.e., chain connecting manner) and properties are closely correlate, and strongly influence rheological properties that reflect microscopic molecular dynamics. This review summarizes the rheological properties of ring polymers and polymers containing intramolecular loops, which are currently being studied actively in terms of sample synthesis and physical property. The ring polymers, which have a well-defined molecular architecture and free of impurities, exhibit rheological properties that differ significantly from those of their linear counterparts. Notably, even minor contamination with linear chain impurities is known to substantially alter the rheological properties of ring polymers. Theoretical molecular modeling studies are being pursed to elucidate these behaviors. The ring polymer analogues consisting of multiple ring chains or intramolecular linkages between ring and linear chains exhibit either unentangled or intermolecular penetration behavior, depending on their molecular architectures. The polymers featuring intrinsically random intramolecular loops, such as single-chain polymeric nanoparticles (SCNPs) and polymeric nanosheets, are also under active investigation in terms of both their synthesis and properties. A deeper understanding of the molecular dynamics and rheological properties of these unique architectural polymers can contribute to the further development of polymer science and industry as well as to the creation of new polymeric nano-materials.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"283 - 294"},"PeriodicalIF":2.2,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1007/s13367-024-00107-z
Yuxuan Pei, Yanjie Zhang, Chengzhi Zheng, Jian Tang, Quan Chen
Stress relaxation measurements under step strain γ are frequently utilized to characterize the nonlinear stress responses of polymeric materials. The reduction degree of the stress amplitude with increasing step strain is quantified by the so-called damping function, h(γ). In this review, we summarize a recent progress in molecular understanding of the damping behavior of associative polymers from both the experimental and theoretical perspectives. The damping is related to the rupture and reconstruction of associative network after applying step strain and before the terminal stress relaxation. Incorporation of this mechanism into the classic sticky Rouse model through the conformation pre-averaging protocol enables quantitative prediction of the damping behavior of randomly associating linear polymers as well as end-associative star polymers, both in the unentangled state.
{"title":"Nonlinear damping of associative polymers","authors":"Yuxuan Pei, Yanjie Zhang, Chengzhi Zheng, Jian Tang, Quan Chen","doi":"10.1007/s13367-024-00107-z","DOIUrl":"10.1007/s13367-024-00107-z","url":null,"abstract":"<div><p>Stress relaxation measurements under step strain γ are frequently utilized to characterize the nonlinear stress responses of polymeric materials. The reduction degree of the stress amplitude with increasing step strain is quantified by the so-called damping function, <i>h</i>(γ). In this review, we summarize a recent progress in molecular understanding of the damping behavior of associative polymers from both the experimental and theoretical perspectives. The damping is related to the rupture and reconstruction of associative network after applying step strain and before the terminal stress relaxation. Incorporation of this mechanism into the classic sticky Rouse model through the conformation pre-averaging protocol enables quantitative prediction of the damping behavior of randomly associating linear polymers as well as end-associative star polymers, both in the unentangled state.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"243 - 252"},"PeriodicalIF":2.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1007/s13367-024-00106-0
Xuesi Gao, Byungmin Lee, Wook Ryol Hwang
In this work, a systematic approach is proposed for quantifying the effective viscosity, effective shear rate, and screw characteristics of non-Newtonian fluids in an unwound rectangular channel screw flow of a metering zone of the single-screw extruder. The analyses are limited to a small helix angle case (less than 6.7 degrees), where the cross-sectional drag velocity component is small enough. We begin by separating the flow within the channel into two individual flows (the drag-driven flow and the adverse pressure-driven flow). Both the correlations between drag velocity and drag force in the drag flow and between flow rate and pressure buildup in the pressure-driven flow are investigated separately. Then, we propose mixture rules for shear rate and energy dissipation for the combined drag and (adverse) pressure-driven flows in the rectangular channel. The flow quantification approach of the combined flow is established by incorporating the correlations observed in the individual flows with a velocity ratio (the ratio of the drag velocity to the flow rate). The flow quantification method was validated using three non-Newtonian fluids (power law fluid models, a Carreau fluid model, and a regularized Herschel–Bulkley fluid model), through extensive numerical simulations with a 2.5D hybrid scheme. The proposed quantification method can be applied for estimating the relationship between torque, pressure buildup and throughput in the single-screw process with a small helix angle. Theoretical predictions agree well with numerical simulations, with maximum relative errors of 3.3%, and 11% for drag force and pressure buildup, respectively.
{"title":"Quantification of flows in a rectangular channel of a single-screw extruder with a small helix angle based on the energy dissipation rate","authors":"Xuesi Gao, Byungmin Lee, Wook Ryol Hwang","doi":"10.1007/s13367-024-00106-0","DOIUrl":"10.1007/s13367-024-00106-0","url":null,"abstract":"<div><p>In this work, a systematic approach is proposed for quantifying the effective viscosity, effective shear rate, and screw characteristics of non-Newtonian fluids in an unwound rectangular channel screw flow of a metering zone of the single-screw extruder. The analyses are limited to a small helix angle case (less than 6.7 degrees), where the cross-sectional drag velocity component is small enough. We begin by separating the flow within the channel into two individual flows (the drag-driven flow and the adverse pressure-driven flow). Both the correlations between drag velocity and drag force in the drag flow and between flow rate and pressure buildup in the pressure-driven flow are investigated separately. Then, we propose mixture rules for shear rate and energy dissipation for the combined drag and (adverse) pressure-driven flows in the rectangular channel. The flow quantification approach of the combined flow is established by incorporating the correlations observed in the individual flows with a velocity ratio (the ratio of the drag velocity to the flow rate). The flow quantification method was validated using three non-Newtonian fluids (power law fluid models, a Carreau fluid model, and a regularized Herschel–Bulkley fluid model), through extensive numerical simulations with a 2.5D hybrid scheme. The proposed quantification method can be applied for estimating the relationship between torque, pressure buildup and throughput in the single-screw process with a small helix angle. Theoretical predictions agree well with numerical simulations, with maximum relative errors of 3.3%, and 11% for drag force and pressure buildup, respectively.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"37 1","pages":"67 - 79"},"PeriodicalIF":2.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1007/s13367-024-00105-1
Hyeong Yong Song, Si Yoon Kim, Min Seo Park, Jun Dong Park, Kyu Hyun
This study investigated the effect of mechanical stirring time on liquid gallium (Ga)-oxide amalgams using linear and nonlinear viscoelastic properties in dynamic oscillatory shear. The liquid Ga-oxide amalgams with different stirring times were prepared by exposing liquid Ga to the atmosphere under continuous stirring. Linear viscoelasticity of all amalgams exhibited an elastic-dominant behavior. When plotted versus stirring time, elastic modulus increased gradually, which was described successfully by a power-law-type equation for a percolation behavior. The nonlinear viscoelasticity of the amalgams was analyzed using the conventional strain-sweep data and the sequence of physical processes (SPP) method. The critical strain amplitudes determined from the strain-sweep data showed that the yielding of the amalgams occurred earlier and more gradually with increasing stirring time. The SPP analysis using transient Cole–Cole plots revealed that all amalgams experienced intracycle nonlinear behavior consisting of three physical processes (recovery, elastic softening, and yielding) within an oscillation cycle. Intriguingly, the structure recovery rate evaluated by the maximum intracycle elasticity exhibited a nonmonotonic behavior, where the maximum recovery rate was achieved at the stirring time of 5 min. Finally, taking both linear and nonlinear properties, we suggested a material–property co-plot for the printability evaluation of liquid Ga-oxide amalgams.
{"title":"Effect of stirring time on viscoelastic properties of liquid gallium-oxide amalgams","authors":"Hyeong Yong Song, Si Yoon Kim, Min Seo Park, Jun Dong Park, Kyu Hyun","doi":"10.1007/s13367-024-00105-1","DOIUrl":"10.1007/s13367-024-00105-1","url":null,"abstract":"<div><p>This study investigated the effect of mechanical stirring time on liquid gallium (Ga)-oxide amalgams using linear and nonlinear viscoelastic properties in dynamic oscillatory shear. The liquid Ga-oxide amalgams with different stirring times were prepared by exposing liquid Ga to the atmosphere under continuous stirring. Linear viscoelasticity of all amalgams exhibited an elastic-dominant behavior. When plotted versus stirring time, elastic modulus increased gradually, which was described successfully by a power-law-type equation for a percolation behavior. The nonlinear viscoelasticity of the amalgams was analyzed using the conventional strain-sweep data and the sequence of physical processes (SPP) method. The critical strain amplitudes determined from the strain-sweep data showed that the yielding of the amalgams occurred earlier and more gradually with increasing stirring time. The SPP analysis using transient Cole–Cole plots revealed that all amalgams experienced intracycle nonlinear behavior consisting of three physical processes (recovery, elastic softening, and yielding) within an oscillation cycle. Intriguingly, the structure recovery rate evaluated by the maximum intracycle elasticity exhibited a nonmonotonic behavior, where the maximum recovery rate was achieved at the stirring time of 5 min. Finally, taking both linear and nonlinear properties, we suggested a material–property co-plot for the printability evaluation of liquid Ga-oxide amalgams.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"375 - 386"},"PeriodicalIF":2.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1007/s13367-024-00104-2
Luis Antonio Ramirez-Torres, Diola Marina Nuñez-Ramirez, Luis Medina-Torres, Octavio Manero
This research aims to study the rheological behavior and impurities dissolution kinetics in a bioleaching process of two particle sizes and three different pulp densities, which are analyzed and compared. It was found that the small particle size with 40% (w/w) pulp density provides the maximum dissolution of impurities in the shortest bioleaching time (in 2 days). Furthermore, through a CFD simulation in a system with 40% (w/w) pulp density and 44 μm particle size, a stirring speed of 700 rpm provides the best mixing conditions in the bioreactor, enabling good distribution of recirculation zones and adequate streamline patterns with a viscosity map that minimizes regions of high and low viscosity.
{"title":"Study of the impurity dissolution kinetics, rheological characterization, and hydrodynamic aspects during the bioleaching of iron ore pulp in a bioreactor","authors":"Luis Antonio Ramirez-Torres, Diola Marina Nuñez-Ramirez, Luis Medina-Torres, Octavio Manero","doi":"10.1007/s13367-024-00104-2","DOIUrl":"10.1007/s13367-024-00104-2","url":null,"abstract":"<div><p>This research aims to study the rheological behavior and impurities dissolution kinetics in a bioleaching process of two particle sizes and three different pulp densities, which are analyzed and compared. It was found that the small particle size with 40% (w/w) pulp density provides the maximum dissolution of impurities in the shortest bioleaching time (in 2 days). Furthermore, through a CFD simulation in a system with 40% (w/w) pulp density and 44 μm particle size, a stirring speed of 700 rpm provides the best mixing conditions in the bioreactor, enabling good distribution of recirculation zones and adequate streamline patterns with a viscosity map that minimizes regions of high and low viscosity.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"37 1","pages":"29 - 42"},"PeriodicalIF":2.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-024-00104-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-12DOI: 10.1007/s13367-024-00102-4
Suyeon Lee, Dayoung Kim, Dong Gi Seong
Aerogel has gained much attention as a promising nanostructure which contributes to the high dispersity of nanofillers and structural stability. However, the difficulty of fabricating robust aerogels using various nanofillers and producing aerogels for the scale-up process is still challenging for expanding applications of aerogels. We fabricate the ternary aerogel particle consisting of MXene, carbon nanotube (CNT), and polydopamine (PDA), and it has structural stability owing to the outstanding adhesion property of PDA. The fabricated aerogel particles are also highly favorable for industrial application because if its ease of handling and scaling up compared to the bulk aerogels. In this study, various parameters, such as polymerization time of PDA and fabrication method, are utilized to find the optimal conditions for fabricating robust and stable aerogel nanostructures. Ternary aerogel exhibits a unique nanostructure with self-staked MXene and bridged CNT between MXene layers, which is expected to form a more effective conducting pathway. Moreover, rheological analysis revealed that the storage modulus recovered even after severe deformation, indicating that the fabricated aerogel possesses structural stability. It is anticipated that these ternary aerogel particles have the potential to be applied in the effective platform for nanocomposites in various industrial fields.
{"title":"Construction of self-stacking nanostructure with MXene and CNT through dopamine polymerization","authors":"Suyeon Lee, Dayoung Kim, Dong Gi Seong","doi":"10.1007/s13367-024-00102-4","DOIUrl":"10.1007/s13367-024-00102-4","url":null,"abstract":"<p>Aerogel has gained much attention as a promising nanostructure which contributes to the high dispersity of nanofillers and structural stability. However, the difficulty of fabricating robust aerogels using various nanofillers and producing aerogels for the scale-up process is still challenging for expanding applications of aerogels. We fabricate the ternary aerogel particle consisting of MXene, carbon nanotube (CNT), and polydopamine (PDA), and it has structural stability owing to the outstanding adhesion property of PDA. The fabricated aerogel particles are also highly favorable for industrial application because if its ease of handling and scaling up compared to the bulk aerogels. In this study, various parameters, such as polymerization time of PDA and fabrication method, are utilized to find the optimal conditions for fabricating robust and stable aerogel nanostructures. Ternary aerogel exhibits a unique nanostructure with self-staked MXene and bridged CNT between MXene layers, which is expected to form a more effective conducting pathway. Moreover, rheological analysis revealed that the storage modulus recovered even after severe deformation, indicating that the fabricated aerogel possesses structural stability. It is anticipated that these ternary aerogel particles have the potential to be applied in the effective platform for nanocomposites in various industrial fields.</p>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"341 - 349"},"PeriodicalIF":2.2,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnetorheological elastomers (MREs), which can change their rheological properties under magnetic stimuli, have seen a surge of interest for their utility in sophisticated vibration isolation systems. This study investigates the impact of carbonyl iron particle (CIP) concentration and magnetic field strength during the curing process on the rheological properties of MREs. An Artificial Neural Network (ANN) model using Bayesian optimization was also developed to predict properties and its accuracy was confirmed by comparing it with the experimental results. MRE samples with varying volumes of CIPs (5, 10, 15, and 20%) were prepared using a matrix of room temperature vulcanized silicon elastomer, specifically Elastosil 4511. During the curing process, MRE samples were subjected to different magnetic field strengths (0, 0.15, 0.3, 0.5 T). The rheological behavior was analyzed using a dynamic shear rheometer (DSR), conducting amplitude, frequency, and magnetic sweep experiments. The study reveals that higher CIP concentrations initially increase MRE stiffness, but a pronounced Payne effect emerges at higher strains. Furthermore, elevated curing magnetic fields and magnetic sweeps significantly enhance MRE stiffness and response. The optimized ANN model, developed through the Bayesian method, demonstrated a marked potential in accurately predicting the behavior of MREs under various conditions.
{"title":"Dynamic rheological behavior and ANN model with Bayesian optimization for elastosil-based magnetorheological elastomers","authors":"Nishant Kumar Dhiman, Sandeep M. Salodkar, Gagandeep Sharma, Chander Kant Susheel","doi":"10.1007/s13367-024-00103-3","DOIUrl":"10.1007/s13367-024-00103-3","url":null,"abstract":"<div><p>Magnetorheological elastomers (MREs), which can change their rheological properties under magnetic stimuli, have seen a surge of interest for their utility in sophisticated vibration isolation systems. This study investigates the impact of carbonyl iron particle (CIP) concentration and magnetic field strength during the curing process on the rheological properties of MREs. An Artificial Neural Network (ANN) model using Bayesian optimization was also developed to predict properties and its accuracy was confirmed by comparing it with the experimental results. MRE samples with varying volumes of CIPs (5, 10, 15, and 20%) were prepared using a matrix of room temperature vulcanized silicon elastomer, specifically Elastosil 4511. During the curing process, MRE samples were subjected to different magnetic field strengths (0, 0.15, 0.3, 0.5 T). The rheological behavior was analyzed using a dynamic shear rheometer (DSR), conducting amplitude, frequency, and magnetic sweep experiments. The study reveals that higher CIP concentrations initially increase MRE stiffness, but a pronounced Payne effect emerges at higher strains. Furthermore, elevated curing magnetic fields and magnetic sweeps significantly enhance MRE stiffness and response. The optimized ANN model, developed through the Bayesian method, demonstrated a marked potential in accurately predicting the behavior of MREs under various conditions.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"36 4","pages":"351 - 374"},"PeriodicalIF":2.2,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141921247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1007/s13367-024-00101-5
Yanping Hao, Leilei Chen, Fan Wang, Qingkui Chen, Shuangli Li, Weiwei Zhang, Shengnan Zhang, Hongchi Tian, Huili Yang
In this work, a one-step reactive extrusion method was adopted to improve comprehensive properties of poly(butylene adipate-co-terephthalate) (PBAT) by melt blending with two chain extenders, including polycarbodiimide (PCDI) and multi-functional epoxy polymer (ADR). Their influences on rheological behaviors, aging properties, and thermal stability of PBAT were explored, and the detailed mechanisms were also discussed. It was found that the terminal carboxyl content of PBAT decreased with addition of PCDI and ADR. When 1.0 wt% PCDI was added, the terminal carboxyl content deceased by 70.3%. This indicated that the reaction between the two chain extenders and the terminal hydroxyl and carboxyl groups of PBAT enhanced to perform the chain extension, which increased the molecular weight, storage modulus, loss modulus, and complex viscosity of PBAT, and different relaxation processes were observed for different samples by Han and Cole–Cole plots. Damp-heat aging resistance measurements showed correlation with terminal carboxyl content in PBAT. And reducing the terminal carboxyl content in PBAT was shown to increase hydrolytic stability. For PBAT with 1.0 wt% PCDI blend, the tensile strength and elongation at break retention were above 70%. In addition, the thermal stability of PBAT was also improved due to the chain extension in the blends, which retarded degradation. The analysis results indicated that the comprehensive performance of modified PBAT was the best when 1.0 wt% PCDI was added.
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