CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 40
·期 11
·1402-1410
·
IF 3.815
Ni Qing-Sheng,Du Miao,Shan Guo-Rong,Song Yi-Hu,Zheng Qiang
Poly(vinyl alcohol) (PVA) is usually processed and used in a form of aqueous dispersion. A large number of inter- and intramolecular hydrogen bonds make it very difficult to obtain suitable rheological behavior for processing. In this study, carbon particles with different topological shapes were added into PVA aqueous dispersion to tune the steady and dynamic rheological behavior. The results show that the zero-dimensional particles (carbon black, CB) increase monotonically the zero-shear viscosity of PVA dispersion, while the one-dimensional particles (carbon nanotubes, CNTs) make it first increase, and then decrease and rise again, like an N-shape, and the two-dimensional particles (graphene oxide, GO) can make it first decrease and then increase, exhibiting a U-shape. It is believed that the topological shape of the carbon particles brought about these discrepancies. The zero-dimensional particles mainly act as physical crosslinking points due to their small size. While at a certain content, both CNTs and GO can destroy the intermolecular hydrogen bonds between PVA chains because the PVA chains can twine around the slim CNTs and the large planar size of GO prevents the adsorbed PVA from forming hydrogen bond with other chains. The high hydroxyl value of carbon particle surface could strengthen this effect. It is expected that the viscosity of polymer dispersion can be regulated by particles with different topological shape and the surface characteristic, so as to widen the operable concentration range during preparing composite functional materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Chuandong Ma,Wenqi Zhang,Zhisen Li,Junxiang Wang,Qingbiao Wang,Lin Li,Xiaofang You
In this study, high-concentration inorganic salt wastewater containing microplastics (MPs) was used to prepare MPs-coal wastewater slurry (MPs-CWWS). The rheological behavior, stability, and solid content of the slurry were discussed, and the interfacial interaction mechanism between particles was analyzed. Experimental results show that the presence of inorganic salts in the system will cause an increase in viscosity. This is because cations neutralize the negative charges on particle, resulting in a reduction in the electrostatic repulsion between particles. In addition, a large amount of water is adsorbed due to “ionic bonding”, resulting in a reduction in free water content and therefore a decrease in the solid loading of the suspended system. The enhanced stability is attributed to the thickening of the hydrated film. MPs have strong hydrophobicity and are easy to adsorb dispersants due to non-polar effects, which increases the negative charge and steric hindrance effect on the surface. MPs promote the dispersion of particles in the slurry. The extended-DLVO theoretical calculation results show that electrostatic repulsion and steric hindrance effect are the main forces promoting particle dispersion. Electrostatic repulsion plays a key role in promoting particle dispersion. The extended-DLVO theoretical calculations verify that the main reason for the increase in viscosity caused by inorganic salts is the decrease in electrostatic interaction energy. The existence of MPs can reduce the negative effects caused by inorganic salts.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Dinghui Chen,Dawei Luo,Weijun Zhen,Ling Zhao
In the work, organic saponite (OSAP) was modified with dioctadecyl dimethyl ammonium chloride and saponite by intercalation reaction. Moreover, functionalized OSAP (FOSAP) was prepared with OSAP, BASF chain extender Joncryl ® ADR 4468 and p -phenylenediamine. The optimum reaction conditions of FOSAP were optimized by orthogonal experiment. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) results demonstrated that saponite had been successfully modified. Moreover, FOSAP/poly (lactic acid) (PLA) nanocomposites were prepared by melting intercalation with PLA and FOSAP. The mechanical properties, rheological behavior and crystallization properties of FOSAP/PLA nanocomposites were investigated. Mechanical properties showed that the impact strength and elongation at break of FOSAP/PLA nanocomposites reached 13.21 KJ/m 2 and 71.47%, respectively, when the amount of FOSAP in PLA was 0.3 wt%. In addition, the Cole-Cole curve showed that FOSAP had strong interfacial compatibility with PLA. Furthermore, the crystallization behaviors of PLA before and after modification during isothermal crystallization at 150 °C were investigated by Rheonaut technology for simultaneous rheology and FTIR, which demonstrated that FOSAP effectively promoted the crystallization of PLA and increased the storage modulus . Avrami equation showed that FOSAP changed the nucleation growing mode and significantly accelerated the crystallization rate of PLA, therefore the comprehensive performance of PLA was improved.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 16
·2734
·
IF 4.329
Bin Luo,Yiding Zhong,Hualing Chen,Zicai Zhu,Yanjie Wang
Electroactive PVC gel is a new artificial muscle material with good performance that can mimic the movement of biological muscle in an electric field. However, traditional manufacturing methods, such as casting, prevent the broad application of this promising material because they cannot achieve the integration of the PVC gel electrode and core layer, and at the same time, it is difficult to create complex and diverse structures. In this study, a multi-material, integrated direct writing method is proposed to fabricate corrugated PVC gel artificial muscle. Inks with suitable rheological properties were developed for printing four functional layers, including core layers, electrode layers, sacrificial layers, and insulating layers, with different characteristics. The curing conditions of the printed CNT/SMP inks under different applied conditions were also discussed. The structural parameters were optimized to improve the actuating performance of the PVC gel artificial muscle. The corrugated PVC gel with a span of 1.6 mm had the best actuating performance. Finally, we printed three layers of corrugated PVC gel artificial muscle with good actuating performance. The proposed method can help to solve the inherent shortcomings of traditional manufacturing methods of PVC gel actuators. The printed structures have potential applications in many fields, such as soft robotics and flexible electronic devices.Keywords:direct writing;PVC gel;artificial muscle;rheological behavior;integrated printing
研究领域:
软体机器人
·
材料科学
·
生物仿生学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Xiuying Qiao,Lijun Wang,Zhengzhong Shao,Kang Sun,Reinhard Miller
In this study, oil/water emulsions stabilized by natural silk fibroin were prepared, and the effects of silk fibroin concentration ( φ SF ), oil volume fraction ( ϕ o ) and oil type on the stability and rheological behavior investigated. After creaming and reaching a stable state, the residual emulsion fraction increases with an increase in φ SF , ϕ o and oil polarity, while the size of emulsion droplets decreases with an increase in φ SF and oil polarity but a decrease in ϕ o . Due to the colloidal networks formed by the dispersed oil droplets, the emulsions show a predominantly elastic behavior with a frequency independent modulus and low phase angle. However, the droplet networks are not very strong, and a remarkable shear-thinning behavior occurs for all emulsions during steady shear flow. Moreover, stress overshoot also appears for some emulsions with low φ SF and polar oil during transient shear flows, due to the deformation of droplets before the breakage of their associates. The modulus, viscosity and yield stress become larger with the increase of φ SF , ϕ o and oil polarity, which is very beneficial for strengthening the creaming stability of the emulsions.
研究领域:
食品科学
·
材料科学
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2020
·Vol. 49
·期 3
·2100-2109
·
IF 1.774
Yazdan Ali,Wang Jizhe,Nan Ce-Wen,Li Liangliang
The role of thermal interface materials (TIMs) has become substantial due to their critical applications in electronic devices for effective heat dissipation. Dimethyl silicone oil-based thermal pastes are widely used as TIMs because they can provide an intimate bonding between the heat sink and the electronic chip; however, the thermal conductivities of typical silicone oil-based thermal pastes are low. In this study, we prepared thermally conductive emulsion-based thermal pastes with two kinds of boron nitride (BN) fillers and investigated their rheological behavior and thermal conductivities. The emulsion was composed of dimethyl silicone oil, n-butanol, and sorbitan monooleate (Span 80) as an emulsifier. The fillers were boron nitride fibers (BNFs) and boron nitride nanosheets (BNNSs). The viscosity, storage modulus, and loss modulus of the emulsion-based pastes were smaller than those of the corresponding silicone oil-based ones. The thermal conductivities of the emulsion based pastes were larger than those of the silicone oil-based ones because of their lower viscosity and higher baseline thermal conductivity. The pastes with BNNSs had larger thermal conductivities in comparison with the corresponding ones with BNFs. To further enhance the thermal conductivity, BNNSs were coated with two silane coupling agents, 3-aminopropyl-triethoxy silane (KH550) and 3-(Trimethoxysilyl)propyl methacrylate (KH570), and then introduced into the emulsion. The maximum thermal conductivity was 1.04 W m −1 K −1 for the emulsion-based paste with KH550-coated BNNSs at a filler loading of 39 vol.%, which was a ∼ 7-fold increase in comparison with that of neat silicone oil (0.13 W m −1 K −1 ).
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
E-POLYMERS
·
2024
·Vol. 24
·期 1
·
IF 3.2
Hao Ming,Yinyan Guan,Cong Geng,Yingjun Gao,Jing Meng,Jiyan Liang
Capacitive deionization electrode prepared by coating was commonly investigated, with polymer solution as binder and active particles as adsorbent. In the coating process, microstructure constituted by the two components was damaged by shear, then rebuilt when shear was removed. The microstructure strongly influenced the surface structure of the coated electrodes, further to performance and cycle life. The discussion of the interaction between the components in the coating process facilitates the identification of structural mechanisms. Rheology bridged the flow regimes in macroscale and interaction in microscale, through which the interaction between the polymer and particles can be investigated in a macroscopic phenomenon. In this study, hydrophilic polymer, poly(vinyl alcohol) (PVA), and poly(ethylene oxide) (PEO) were used as binders to prepare the suspension for coating. The influence of polymer molecular structure to interaction and microstructure was investigated by rheology. Results showed that the flexibility of polymer determined the adsorption morphology, leading to different flocculation structures. For rigid PVA, a 3d-crosslinked network was formed, giving a tough coating. While for flexible PEO, encapsulation structure was formed, leading to a brittle coating. A model based on bridging flocculation was evaluated to describe the formation and destruction of the flocculation structure. And a rheological method for binder selection and coating operation was proposed.
Graphical abstract
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Xingyi Zhu,Jiakang Wang,Ming Yang,Jianzhuang Xiao,Yating Zhang,Francisco A. Gilabert
This paper aims to develop an environmentally friendly and low-carbon geopolymer for 3D printing , which has excellent mechanical and rheological performance. The effect of ground granulated blast furnace slag (GGBS), NaOH and sand on mechanical strengths , 3D printing performance and rheological behavior was investigated to determine the optimum mix proportion for 3D-printed geopolymer. Moreover, polyethylene (PE) fibers were introduced to reinforce the performance of 3D-printed geopolymer. Results show that when the ratio of GGBS, NaOH and sand is 1:0.13:2.67, geopolymer exhibits superior mechanical, 3D printing and rheological properties. Increasing the dosage of GGBS and sand leads to an overall increase in the yield stress but a decrease in the consistency coefficient, indicating that it benefits the stacking and fluidity performance of 3D-printed geopolymer. However, with an increase of NaOH content, the stacking performance increases while the fluidity decreases. Although increasing NaOH and sand content benefits the viscosity recovery performance, an increase in GGBS content has an opposite effect. Incorporating PE fibers significantly increases the flexural strength with an increase of up to 27.8 % and 21.3 % in 7-d and 28-d flexural strength , respectively, given a PE fiber volume of 0.6 %. Increasing the volume of PE fibers leads to a significant rise in the stacking performance but a reduction in the fluidity. Furthermore, adding PE fibers negatively affects the geopolymerization but benefits the hydration process given an increase of Si/Al and Si/Ca ratio identified in PE fiber reinforced 3D-printed geopolymer.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 5
·1953
·
IF 3.748
Yujun Gao,Jingjing Feng,Feng Liu,Zhifu Liu
Silver paste is widely used for low-temperature co-fired ceramic (LTCC) electrodes. In this work, a kind of LTCC silver paste for fine-line screen-printing was developed by considering the effect of the organic vehicle on rheological behavior and screen-printing properties. A step-by-step volatilization mode was applied to screen the mixed organic solvent ofα-terpineol, 2-(2-butoxyethoxy) ethyl acetate (BCA) and dibutyl phthalate (DBP). Theα-terpineol:BCA:DBP ratio of 5:2:3 is selected by considering the volatility, viscosity, and pseudoplasticity of the organic vehicle. Both viscosity and pseudoplasticity of shear-thinning increase with the increase of ethyl cellulose (EC) organic binder content. Three interval thixotropy test (3ITT) was conducted to discuss the thixotropy of silver paste. The minimum printing line width of 13.27 µm is obtained using silver paste with 10 wt% EC, confirming that the homemade paste has good printability.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Lihua Zhang,Wentao Shi,Junqin Wang,Longming Jin,Gang Hu,Qiang Zheng,Haibo Xie,Peng Chen
Gelation and rheological behaviors of cellulose/CO 2 -based reversible ionic liquid (RIL)/DMSO solutions were investigated. The exponents of specific viscosity η sp versus concentration c were determined for wood pulp (WP) and microcrystalline cellulose (MCC) solutions. The complex viscosity acquired using oscillatory shear closely follows the steady shear viscosity, thus revealing the applicability of Cox-Merz rule. The influence of RIL content in the solvent on apparent viscosities, activation energy, intrinsic viscosities, specific viscosity-c[η] master curve, and relaxation time were also investigated. Gelation occurred in this cellulose solution system due to thermal-induced CO 2 release from the decomposition of the CO 2 -based reversible ionic liquid. The formed gel was stable in air, but re-dissolved when exposed to CO 2 , indicating the switch-on and switch-off effects of CO 2 in cellulose dissolution and gelation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2015
·
IF 4.09
Yongzhen Tao,Ruquan Zhang,Weilin Xu,Zikui Bai,Yingshan Zhou,Sanping Zhao,Yan Xu,Danqing Yu
Xanthan-based hydrogels can be used for encapsulating and controlling release of nutrition ingredients, therapeutic agents, and cells in food and tissue engineering applications. Hydroxyl groups on the xanthan gum (XG) chains permitted the formation of the hydrogels through crosslinking XG with sodium trimetaphosphate (STMP). Dynamical oscillation tests were performed to monitor the in situ crosslinking process, and to evaluate the forming kinetics and mechanical stability for the XG-STMP hydrogels. The results indicated that the transition from hydrogen bonding to chemical crosslinking for the XG chains occurred and reached a balance approximately at 25 and 37 °C, respectively. The XG-STMP hydrogel networks with solid-like gel behavior exhibited more elastic and tougher to resist the deformation than the physical XG hydrogels. The XG-STMP hydrogels with porous and interconnected structure displayed good swelling and release-controlled properties. This work provides some valuable and fundamental information of the xanthan-based hydrogels for further application in biomaterials, medical and food engineering.
研究领域:
食品科学
·
生物材料
·
医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2018
·Vol. 18
·期 12
·8419-8425
·
IF 1.354
Fei Guiqiang,Zhang Yu,Wang Xia,Li Xiaorui,Wang Haihua
Cationic poly(urethane-acrylate) emulsifier-free microemulsions are prepared by seeded emulsion polymerization (SPUA) or in-situ emulsion polymerization (IPUA) with (a) or without (b) crosslinking agent hydroxyethyl acrylate (HEA). Furthermore, no surfactant is introduced into
the reaction system. The effect of continuous phase and HEA on the rheological behavior and properties of microemulsions are studied. The results show that IPUA using vinylmonomers as the continuous phase and with HEA (IPUAMB-b) has the highest ζ value, lowest coagulation ratio, smallest
particle size of 48 nm and apparent core–shell structures. Rheological research has concluded that the zero-shear viscosity of IPUAB-b and IPUAM-b emulsion is 6.03×102 and 7.89 Pa·s, respectively, and presents pseudoplastic behavior. However, IPUAMB-b and SPUA-b
display Newtonian behavior with η0 of 0.136 Pa·s and 0.0823 Pa·s, respectively. PUA emulsions display similar rheological behavior when NMP is replaced by the mixture of MMA and BA.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）