{"title":"Surface characteristics of metal-like composites fabricated with aliphatic polyketone","authors":"Ji Won Jeong, Young Seok Song","doi":"10.1007/s13367-023-00061-2","DOIUrl":"10.1007/s13367-023-00061-2","url":null,"abstract":"<div><p>Recently, consumers have shown a growing interest in polymeric products that offer high aesthetic and comfort features, along with superior engineering performance. In response to this demand, we conducted a study on metallic polymer composites, utilizing metal fillers and polymers. To create these composites, micro-sized aluminum flakes and nano-sized spherical aluminum powder were combined with aliphatic polyketone. Furthermore, an ion-beam irradiation process was employed to enhance the surface properties of the products, including surface hardness, modulus, and glossiness. The compounding process was carried out using a twin-screw extruder, and disk-shaped specimens were prepared through injection molding. Subsequently, nitrogen ion-beam irradiation was applied to the prepared specimens. Comprehensive analysis was performed to evaluate the mechanical, aesthetic, structural, and morphological properties of these metal-like composites.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 3","pages":"169 - 178"},"PeriodicalIF":1.3,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00061-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713802","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}
{"title":"Thixotropic behavior and particulate aggregation in a suspension of carbon nanotubes","authors":"Daeun Lee, Sangkyun Koo","doi":"10.1007/s13367-023-00060-3","DOIUrl":"10.1007/s13367-023-00060-3","url":null,"abstract":"<div><p>The present study dealt with the evaluation of the particulate aggregation in a suspension of multi-walled carbon nanotubes using fractal theory and rheological properties including thixotropy. The multi-walled carbon nanotubes are dispersed in Newtonian glycerol in the concentration range between 0.2 and 0.45 wt%. Rheological measurement was performed for the suspension at various dispersion times up to 300 min. The suspension showed thixotropy, shear-thinning behavior, and yield stress. It also exhibited plateaus of storage modulus in frequency and strain sweep tests. As the dispersion time increases, thixotropy, low-shear viscosities, and yield stress increase, and then their increasing rates slow down. Suspension’s electrical conductivity also showed similar behavior as that of thixotropy with the dispersion time. Viscoelastic behavior was combined with a fractal concept to provide the fractal dimensions of the flocs in the suspension at various dispersion times. The fractal dimension tends to decrease with the dispersion time. Conclusively it is interpreted that as the dispersion proceeds flocs become smaller and chain-like, then the reduced and thinned flocs build the wider range of network structures at rest state.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 3","pages":"127 - 135"},"PeriodicalIF":1.3,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00060-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713690","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}
Samuel Muobom Saabome, Jae Eun Lee, Joung Sook Hong, Dong Hak Kim, Kyung Hyun Ahn
{"title":"Mechanical degradation of poly(ethylene terephthalate) and its structural modification by chain extender","authors":"Samuel Muobom Saabome, Jae Eun Lee, Joung Sook Hong, Dong Hak Kim, Kyung Hyun Ahn","doi":"10.1007/s13367-023-00059-w","DOIUrl":"10.1007/s13367-023-00059-w","url":null,"abstract":"<div><p>Characterized by high strength to unit weight, poly(ethylene terephthalate) (PET) remains one of the most widely used engineering plastics, hence the attention to its associated waste and recycling technology development has been paid from academic and industrial perspectives. Herein, we investigate the mechanical degradation of PET through degradative compounding process cycles and the effect of chain extender (Joncryl<sup>®</sup> ADR 4468) to prevent molecular degradation of PET during melt processing. They are characterized based on rheological and mechanical measurements. Characterization of the bottle-grade PET samples reveals low viscosity and crystallinity owing to isophthalic acid units within the PET copolymer structure over PET homopolymer. Mechanical shear and thermal impact by virtue of the increase in rotor speed and temperature are employed to study the degradation of the PET samples. Both samples respond to degradation in successive processing cycles with as much as 70% decrease in their complex viscosity and moduli. The molecular weight of PET copolymer accordingly decreases from 23,400 to 8010 g/mol. Chain scission arising from thermo-mechanical degradation results in high crystallinity by more than five folds in the processed PETs. Attributed to recoupling of the degraded short chains, the chain extender compensates with the increase in viscosity and moduli up to 20% whilst serving to increase crystallinity but almost ineffective in appreciating mechanical performance with barely any significant variation in tensile strength and elongation at break. This study shows that mechanical shear is verified to impact a pronounced degradation on PET more than thermal action on the samples.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 3","pages":"203 - 212"},"PeriodicalIF":1.3,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00059-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713689","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}
Yeeun Kim, Eunji Kim, Dohoon Kim, Chi Won Ahn, Byoung Soo Kim, Kyung Hyun Ahn, Yonghee Lee, Jun Dong Park
{"title":"Tuning the microstructure and rheological properties of MXene-polymer composite ink by interaction control","authors":"Yeeun Kim, Eunji Kim, Dohoon Kim, Chi Won Ahn, Byoung Soo Kim, Kyung Hyun Ahn, Yonghee Lee, Jun Dong Park","doi":"10.1007/s13367-023-00058-x","DOIUrl":"10.1007/s13367-023-00058-x","url":null,"abstract":"<div><p>Since the discovery of MXene, which has been attracting attention as an alluring two-dimensional material with a distinct structure and mechanical and electrical capabilities, numerous attempts have been made to combine MXene with polymer additives to enhance and compensate for MXene’s inherent weakness. In this work, the rheological properties of MXene (Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>)-polymer composite inks of three different polymers with various interaction with MXene particles are examined. Polyethylene glycol (PEG), which is known to physically adsorb on the surface of MXene, improved MXene dispersion while enhancing the viscoelastic property of ink. MXene ink containing polyethylenimine (PEI) was destabilized forming a viscoelastic network structure as PEI of strong positive charge adsorbed on the MXene surface to neutralize negative charge and diminish electrostatic repulsion. In the case of MXene-polyacrylic acid (PAA) composite ink, the formation of hydrogen bonds between MXene and PAA resulted in a dense network structure with high viscoelasticity. In terms of rheological property sensitivity to concentration, MXene ink without polymer additives exhibited power-law behavior with the largest exponent, whereas MXene-polymer composite inks indicated moderate sensitivity. Our findings will aid in the design of MXene-based composites with optimum rheological properties for specific processes such as 3D printing and coating.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"117 - 125"},"PeriodicalIF":1.3,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4428480","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}
{"title":"Influence of cationic polymer on the floccule size of cement pastes containing polycarboxylate superplasticizer and Na-bentonite","authors":"Pengpeng Wen, Zhongjun Feng, Baicun Zheng","doi":"10.1007/s13367-023-00057-y","DOIUrl":"10.1007/s13367-023-00057-y","url":null,"abstract":"<div><p>Influence of cationic polymer (KN) on the floccule size of cement pastes containing plycarboxylate superplasticizer (PCE) and Na-bentonite was studied. The proportion of floccule size and grain size <span>({d}_{f}/{d}_{g})</span> was obtained from a rheological analysis with the application of Herschel–Bulkley model and modified Krieger–Dougherty model. Herschel–Bulkley model was used to gain the yield stress according to our previous study. Cement pastes were investigated both at the beginning and after one hour. The results showed that a high value of <span>({d}_{f}/{d}_{g})</span> was noticed under low shear rate range and then the proportion decreased with the increase of shear rate. For cement paste containing PCE and Na-bentonite in the absence of KN, larger floccule was formed due to the intercalation of polyethylene glycol branch chain of PCE into the interlayer space of Na-bentonite. However, the floccule size of cement pastes obviously decreased with the increasing addition amount of KN. Thus, KN will restrain the formation of floccules in cement pastes containing PCE and Na-bentonite to a certain extent.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"105 - 116"},"PeriodicalIF":1.3,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00057-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5030024","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}
Cheng Hai Hong, Hyo Seon Jang, Seok Jun Oh, Li-hai Fu, Hyoung Jin Choi
{"title":"Electric and magnetic field-responsive suspension rheology of core/shell-shaped iron oxide/polyindole microspheres","authors":"Cheng Hai Hong, Hyo Seon Jang, Seok Jun Oh, Li-hai Fu, Hyoung Jin Choi","doi":"10.1007/s13367-023-00056-z","DOIUrl":"10.1007/s13367-023-00056-z","url":null,"abstract":"<div><p>In this study, conductive polyindole (PIn) was coated onto initially fabricated magnetic iron oxide (Fe<sub>3</sub>O<sub>4</sub>) particles via chemical oxidative polymerization, and the synthesized core–shell structured hybrid smart particles were used as smart electrorheological/magnetorheological (EMR) materials. The synthesized Fe<sub>3</sub>O<sub>4</sub>/PIn particles were characterized using scanning electron microscopy and transmission electron microscopy. In addition, the chemical composition of the synthesized particles was confirmed using Fourier-transform infrared spectroscopy. Their magnetic properties were further analyzed using VSM. Consequently, the Fe<sub>3</sub>O<sub>4</sub>/PIn particle-based suspension, which was both magnetic and conductive, was found to exhibit interesting dual stimuli under both external electric and magnetic fields. Various rheological measurements, including shear simple steady shear and dynamic tests, were employed to evaluate the behavior of typical EMR suspensions. Furthermore, the dielectric properties of the particles were analyzed using an LCR meter. Based on the dielectric spectrum data, the relaxation time (<i>λ</i>) was estimated to be 1.5 × 10<sup>–8</sup> s at the maximum frequency (<i>λ</i> = 1/2πfmax). Measurements conducted using a Turbiscan indicated enhanced sedimentation stability of the particles owing to a decrease in the particle density from 4.34 to 2.93 g/cm<sup>3</sup>.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"95 - 103"},"PeriodicalIF":1.3,"publicationDate":"2023-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00056-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4324125","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}
{"title":"Linear viscoelasticity of covalent adaptable network (CAN) polymers comprising β-amino esters","authors":"Hyeong Yong Song, Gyuri Lee, Suk-kyun Ahn, Kyu Hyun","doi":"10.1007/s13367-023-00054-1","DOIUrl":"10.1007/s13367-023-00054-1","url":null,"abstract":"<div><p>We present an experimental investigation of the linear viscoelasticity for a series of covalent adaptable network (CAN) polymers of <i>β</i>-amino esters possessing tertiary amines at the <i>β</i> position of ester linkages. CAN polymers were synthesized by aza-Michael addition from di-acrylate monomers with or without <i>β</i>-hydroxyl groups using a tri-amine cross-linker. The prepared CAN polymers exhibited dissociative-type bond exchanges by aza-Michael reaction. The additional inclusion of <i>β</i>-hydroxyl group endowed them with associative-type bond exchanges by transesterification. Time–temperature superposition (TTS) was used to construct pseudo-master curves of storage, loss, and stress-relaxation moduli over wide timescales. The results showed that without transesterification, the slow kinetics of aza-Michael reaction considerably retarded terminal relaxation. The introduction of transesterification accelerated terminal relaxation rates but did not modify the overall broadness of terminal relaxation modes. Horizontal shift factors displayed Williams–Landel–Ferry (WLF) dependence below 120 °C but Arrhenius dependence above 120 °C. The former was due to slow segmental dynamics, whereas the latter reflected the characteristic of exchange reaction kinetics. In addition, we also compared and discussed two definitions of topology freezing transition temperature, an important concept for associative-type CANs. Conclusively, the topology freezing transition temperature obtained from the transition of shift factors (WLF → Arrhenius) was a more practical definition for the potential processing and applications of CAN polymers.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"69 - 79"},"PeriodicalIF":1.3,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00054-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4867280","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}
Titus Ntow Ofei, Elie Ngouamba, Nils Opedal, Bjørnar Lund, Arild Saasen
{"title":"Rheology assessment and barite sag in a typical North Sea oil-based drilling fluid at HPHT conditions","authors":"Titus Ntow Ofei, Elie Ngouamba, Nils Opedal, Bjørnar Lund, Arild Saasen","doi":"10.1007/s13367-023-00055-0","DOIUrl":"10.1007/s13367-023-00055-0","url":null,"abstract":"<div><p>The occurrence of barite sag in drilling fluids has relatively often been the cause for gas kicks in oilwell drilling. The subsequent absorption of gas into drilling fluid could lower the density and reduce the viscosity of the drilling fluid, thereby aggravating both pressure control and hole cleaning. In this paper, we present experimental measurements of rheological properties and barite sag in a typical North Sea oil-based drilling fluid at downhole pressure and temperature conditions. A new experimental apparatus was setup for barite sag measurements at static condition with operational temperature and pressure capabilities up to 200 °C (392°F) and 1000 bar (14,503.8 psi), respectively. Rheometry measurements were conducted on fluid samples with and without barite particles at operating conditions up to 90 °C and 100 bar. We observed that at a typical shear rate of 250 s<sup>−1</sup>, which is experienced in 8.5″ hole annulus, the viscosity of fluid sample with barite increased nearly three times as that of the fluid sample without barite as the temperature and pressure increased. However, temperature effect on viscosity dominates at high shear rates compared to pressure effect. Furthermore, the fluid samples showed more shear-thinning effect with increasing yield stress as the temperature increased. On the other hand, barite sag measurements revealed that whereas fluid samples under high pressure are less prone to sag, high temperature fluid samples, however, promote sag significantly. The data from this study are useful to validate extrapolations used in computational models and to improve understanding and operational safety of sag phenomena at downhole conditions. We also discuss the importance of this study in optimizing drilling operations.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"81 - 94"},"PeriodicalIF":1.3,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00055-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4828042","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}
{"title":"A review of experimental methods for characterising composite viscosities of continuous fibre-reinforced polymer composites","authors":"Jinhuo Wang, Yang Han, Xiaohong Ge, Zhengbing Qi, Jun Zhao, Rongwen Wang, Huawei Wu, Taiping Han, Shaoxun Sun, Hui Wang, Jia Lin, Yuejun Liu, Xiangsong Kong, Qiming Chen, Xiangxu Zeng","doi":"10.1007/s13367-023-00053-2","DOIUrl":"10.1007/s13367-023-00053-2","url":null,"abstract":"<div><p>Optimisation design of composite structures requires an accurate predictive model for forming behaviour. The simulation process contains a number of model parameters which include transverse and longitudinal viscosities of continuous fibre-reinforced viscous composites, fundamental to predicting the shear rheology. Shearing the unidirectional composite along the fibre direction gives a measure of the longitudinal viscosity (LV), whilst shearing across or transverse to the fibre direction gives a measure of the transverse viscosity (TV). Numerous experimental work was conducted in the past to measure these two viscosities for various materials. However, conflicting measurements by different test methods were obtained and these apparent discrepancies had not yet been systematically investigated in any single study. This paper reviews previous work on characterisation techniques to further understand the cause of such discrepancy, and hence to improve measurement accuracy, which would benefit future work on theoretical modelling of the composite viscosities and optimisation simulation of composites forming. Some important findings, such as effects of resin-rich areas, contributory factors of elastic effects, non-Newtonian behaviour for composites with Newtonian matrix, aspect ratio and end effects of test samples, geometry effects of fibres and fibre rearrangement during shearing, existence of a mathematical relationship between LV and TV and necessary benchmarking exercise using Newtonian matrix composites, were summarised.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 2","pages":"57 - 68"},"PeriodicalIF":1.3,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5043770","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}
{"title":"Comparative study of two-relaxation time lattice Boltzmann and finite element methods for a planar 4:1 contraction flow: a Newtonian fluid at finite Reynolds numbers","authors":"Young Ki Lee","doi":"10.1007/s13367-023-00052-3","DOIUrl":"10.1007/s13367-023-00052-3","url":null,"abstract":"<div><p>We study the flow behavior of a Newtonian fluid in a planar 4:1 contraction channel using two numerical methodologies: the two-relaxation time lattice Boltzmann method (TRT-LBM) and the finite element method (FEM). To confirm the validity of the TRT-LBM, hydrodynamic quantities such that velocity, pressure, and vortex are carefully investigated at the wide ranges of Reynolds numbers (Re = 0.1–100). At first, we analyze the velocity along the channel. The results of TRT-LBM look reasonable and also coincide with the analytical solution and FEM results. Richer features are observed in the pressure profile along the flow direction. At low Reynolds numbers, the one-step change of the slope in the pressure profile is observed near the contraction region. The slope gradually grows up with the increase of Reynolds numbers, and eventually, this evolves the two-step change. Non-monotonic behavior is observed in the characteristics of the vortex. The size of the vortex non-linearly decreases as the Reynolds number increases. Also, the center of the vortex gradually moved toward the corner of the channel as an increase of Reynolds numbers with non-linearity. Not only the velocity and the pressure profiles but also the characteristics of the vortex quantitatively coincide in TRT-LBM and FEM results. Through this study, we confirm the robustness of the TRT-LBM as a simulation tool to investigate inertial flow in a planar contraction geometry.</p></div>","PeriodicalId":683,"journal":{"name":"Korea-Australia Rheology Journal","volume":"35 1","pages":"47 - 54"},"PeriodicalIF":1.3,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13367-023-00052-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4531445","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}