MACROMOLECULES
·
2018
·
IF 5.914
Zhukang Du,Xiaolong Yan,Renfeng Dong,Kang Ke,Biye Ren,Zhen Tong
Telechelic associative polymers (TAPs) can form a dynamic transient network in water and have been widely used as rheological modifiers for improving solution rheological properties in many industrial fields. In this work, we designed and prepared a novel photoresponsive coumarin-functionalized telechelic associative model polymer (CouTAP), which was used to investigate the influence of light-induced dimerization of coumarin end groups on the polymer structure and solution rheological properties. The effects of light intensity, irradiation time, polymer concentration, and temperature on the transient network and rheological behavior of the CouTAP aqueous solution were studied in detail. The rheological properties of the dimerized CouTAP aqueous solution show weak temperature dependence, and the dynamics hardly depends on concentration due to the transformation of triblock to multiblock polymers. A novel transient network model composed of train loops and bridges covalently linked to train loops was proposed to describe the unique solution properties. This work will not only provide new insights into the influence of the light-induced dimerization of coumarin end groups on the network structure and rheological properties of CouTAP solution but also opens a new perspective for the controlled self-assembly of amphiphilic polymers and some special applications of TAPs in the manufacturing and transmission of soft materials, waterborne coating, inks, medicines, cosmetics, and so on.
研究领域:
高分子化学
·
材料科学
·
流变学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 11
·2763
·
IF 3.426
Munir Hussain,Sohail Yasin,Hafeezullah Memon,Zhiyun Li,Xinpeng Fan,Muhammad Adnan Akram,Wanjie Wang,Yihu Song,Qiang Zheng
In this paper we designed greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products. Herein 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) ionic liquid was combined with silane coupling agent to formulate the nanocomposites. The impact of [EMIM]OAc on silica dispersion in a nitrile rubber (NBR) matrix was investigated by a transmission electron microscope and scanning electron microscopy. The combined use of the ionic liquid and silane in an NBR/silica system facilitates the homogeneous dispersion of the silica volume fraction (φ) from 0.041 to 0.177 and enhances crosslinking density of the matrix up to three-fold in comparison with neat NBR, and also it is beneficial for solving the risks of alcohol emission and ignition during the rubber manufacturing. The introduction of ionic liquid greatly improves the mechanical strength (9.7 MPa) with respect to neat NBR vulcanizate, especially at high temperatures e.g., 100 °C. Furthermore, it impacts on rheological behaviors of the nanocomposites and tends to reduce energy dissipation for the vulcanizates under large amplitude dynamic shear deformation.Keywords:nitrile butadiene rubber;rheology;ionic liquids;tensile properties
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
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2022
·
IF 6.056
Chuangchuang Zhang,Shwetha Narayanamoorthy,Shuangxi Ming,Kehu Li,Dennis Cantre,Zhongquan Sui,Harold Corke
This study aims to explore diversity in rheological properties, structure and digestibility of starches isolated from 16 common bean ( Phaseolus vulgaris L.) varieties from Europe and Asia. All common bean starches showed C A -type (closer to A-type) crystallinities. Relative crystallinity varied from 27.8% to 32.9% with a similar coefficient of variation (CV: 5.0%–6.0%) to 1045/1014 cm −1 ratio (varied from 0.429 to 0.508). A peak position shift occurred at 989 and 1014 cm −1 . The peak intensity at 989, 1014 and 1045 cm −1 varied greatly and the variation followed the order: at 989 > 1014 > 1045 cm −1 . A great variation was also observed for the presence of hydroxyl group and the C–O bond stretching. Rapidly digestible starch, slowly digestible starch and resistant starch contents varied from 61.5% to 73.0% (CV: 4.7%), 0.3% to 7.2% (CV: 53.7%) and 23.9% to 35.4% (CV: 11.4%), respectively. CV of storage modulus (G′) and loss tangent (tan δ) were 29.4%–39.4% and 11.9%–36.1%, respectively. G′ max (maximum G′ during heating) varied from 2.52 to 10.32 kPa. These starches showed high G′. This study indicates extensive variation in starch properties among these common bean varieties, which may be useful for selecting varieties for processing, or selecting genotypes for plant breeding.
研究领域:
食品科学
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2021
·
IF 9.147
Yu-Xiao Wang,Ting Zhang,Jun-Yi Yin,Xiao-Jun Huang,Jun-Qiao Wang,Jie-Lun Hu,Shao-Ping Nie
A homogeneous β-glucan (JHMP-70) was obtained from Hypsizygus marmoreus by alkali extraction and ethanol precipitation, and had an apparent molecular weight of 394 kDa. Its fine structure was investigated by FT-IR, methylation combined with GC-MS and 1D and 2D NMR analysis. Results indicated JHMP-70 was a branched β-(1 → 6)-glucan substituted at O -3 by the non-reducing β-Glc p and/or β-(1 → 3)-linked β-Glc p side chains at a ratio of 1:1. SEM observation revealed that there were micro-spherical shapes intertwined with randomly distributed fibrous filaments. Rheological measurements showed that its flow behavior was highly dependent on the concentration. Newtonian behavior was evident at low concentration, whereas pseudoplastic behavior was observed at high concentration. Besides, the addition of salt ions (Na + or Ca 2+ ) significantly decreased the apparent viscosity of JHMP-70 solution. The low viscosity of JHMP-70 was probably attributed to its structural features, including main chain structure, branching degree and side chain length. This work can provide a basis theory to expand the application of the polysaccharides from H. marmoreus in food industry, because their lower viscosity and superior fluidity are desired in beverage products to impart stability against phase separation without compromising other sensorial properties.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 7
·2816
·
IF 3.4
Ning Wang,Hai Chang,Chi Zhang,Yingna Wu,Rui Yang,Xing Zhang,Zirong Zhai
Maintaining sufficient uniformity and stability of a ceramic slurry throughout the printing cycle is key to ensuring the performance of ceramic parts in ceramic-slurry stereolithography. In this study, a stable three-dimensional network structure was introduced into a slurry to achieve slurry uniformity and stability based on rheology theory. The effects of the particle size, solid loading, dispersant content, and gelling agent content on the stability of the three-dimensional network structure in the slurry were analyzed. Relatively stable three-dimensional network structures were constructed to achieve 4-week stability of micron- and submicron-size particle slurries by adjusting the contents of the dispersant and gelling agent. Stabilization ideas for different particle size ranges are provided. In addition, an empirical stability model was obtained based on the experimental results. When the predicted empirical stability factor ofAwas less than 0.035, the slurry exhibited good stability.Keywords:stereolithography printing;slurry stability;rheology;loss factor;gel behavior
研究领域:
材料科学
·
3D打印
·
流变学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Yijiang Li,Xiaoxia Yang,Zhaohua Wang,Wencheng Xia,Feng Wu,Yujin Sun,Xiangyun Sun,Shiqi Liu
This study researched into the underlying influence mechanism of Ca 2+ and Mg 2+ on the rheological properties of kaolinite slurry through rheological technique, turbidity analysis and DLVO theory calculation. The rheological results showed that both the viscosity and yield stress of kaolinite slurry were reduced under high Ca 2+ /Mg 2+ concentration. The apparent viscosity of slurry containing Mg 2+ was lower than that of slurry containing Ca 2+ , but the yield stress of slurry containing Mg 2+ was higher than that of slurry containing Ca 2+ . Turbidity results showed that Ca 2+ have a stronger turbidity removal effect on kaolinite suspension than Mg 2+ . The agglomeration of kaolinite in the presence of Ca 2+ was greater than that in the presence of Mg 2+ . The DLVO theoretical calculation results indicated that there was strong attractive energy between silica face-alumina face, silica face-edge face and edge face-edge face under 1 mmol/L Ca 2+ /Mg 2+ . There were repulsive energy barriers between the silica face-silica face, as well as between the alumina face-alumina face and alumina face-edge face. However, there was an attractive energy between the alumina face-edge face under 1 mmol/L Mg 2+ . The kaolinite agglomeration was a basal face-basal face (F-F) structure with tight and large under 1 mmol/L Ca 2+ , but the kaolinite agglomeration was F-F and edge face-basal face (E-F) structure with loose and large under 1 mmol/L Mg 2+ . The E-F structure in the presence of Mg 2+ caused high yield stress of kaolinite slurry. Under high ions concentration, there was a weak attraction or repulsion between basal faces of kaolinite, but there was an attractive effect between the edge faces. The kaolinite agglomerates were edge face-edge face (E-E) structure with small and even dispersed, resulting in a low viscosity of the slurry. The conclusion of this study provides a basis for regulating the rheological properties of rich-clay slurry during mineral processing.
研究领域:
矿物加工工程
·
胶体化学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Jianhua Hu,Jiye Shan,Jianqing Zhao,Zhen Tong
The isothermal curing kinetics of a flame-retardant epoxy resin containing DOPO (1.5 wt% of phosphorus) with hardener DICY was investigated using differential scanning calorimetry and oscillatory shear rheometry. The glass transition temperature T g increased with conversion α measured by DSC. When the curing temperature is lower than T g ∞ of the completely cured epoxy, the curing kinetics at high α became diffusion-control due to that cured epoxy restricted the diffusion of the reactants to decelerate curing. The modified Kamal model including the diffusion factor described curing conversion rate curves quite well. The curing degree θ was established with relative storage modulus, which was measured by the cyclic frequency sweep, and revealed that the transition from liquid to solid during curing appeared later with a slower rate than that for the conversion change, because the network began to form after formation of branched polymer chains. At the modulus transition time, the epoxy samples cured at different temperatures had the same conversion of 0.409, indicating that above this conversion of reactants the effective network was formed to bear the stress.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2023
·
IF 6
Zhenfeng Xie,Yi Wu,Xin Lu
In this study, we encapsulated epigallocatechin gallate (EGCG) in emulsified oil droplets of protein-stabilized emulsions for the first time, with the participation of peppermint essential oil (PEO). Gum arabic (GA) and sodium caseinate (SC) were sufficiently crosslinked to construct the oil-water interface of the emulsion, improving the stability of EGCG in the emulsified oil droplets. When SC and 4 g/kg GA were mixed for 12 h before emulsification, the protein adsorption at the oil-water interface was significantly enhanced. Compared with the SC-stabilized emulsion, the retention of EGCG in the emulsion stabilized by mixing SC and 4 g/kg GA for 12 h increased about 2 and 33 times, respectively, after thermal treatment (30 min at 90 °C) and storage 10 weeks at 4 °C. Moreover, the emulsion stabilized by SC and 4 g/kg GA was resistant to the ionic strength of 0–0.6 mol/L and had predominantly elastic characteristics in the rheological properties. This indicates that the stability of active ingredients in emulsified oil droplets can be improved by regulating the rheological properties of the oil-in-water emulsion. The study is of great value for the efficient encapsulation and stability improvement of hydrophilic active ingredients in emulsified oil droplets based on emulsion systems.
研究领域:
食品科学
·
营养学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 9
·1655
·
IF 4.967
Jun Ye,Zichang Fu,Jiawei Rao,Jian Xiong
The influences of interactions between carboxymethyl cellulose (CMC) and CMC/europium (III)–terbium (III) (CET) on the structure and properties of the resultant CMC/CET films were investigated by rheology at three stages of the film-drying process. According to the water content at different drying times, the kinetics curves during the film-drying process were drawn. Then, the rheology properties of film-forming solutions during the drying process were characterized by dynamic modulus, Han plots, zero shear complex viscosity and relaxation time. When the water content was 90%, the film contained either 0.1 or 0.2 g of CET, which had good fluidity, while the film with 0.3 g of CET was elastic-dominated. Han plots and XRD analyses showed that the interactions between the CMC and CET were not hydrogen bonds but random entanglements. The zero-shear complex viscosity and relaxation time spectrum confirmed that the entanglements enhanced as the CET content increased. Meanwhile, aggregation formed in the solution of CMC with 0.3 g of CET. When CMC-CET films with different CET additions were compared, the film with 0.2 g of CET had an even and tight sheet structure, the greatest fluorescence intensity, and superior tensile strength of 78.76 MPa.Keywords:fluorescent carboxymethyl cellulose;rheological properties;mechanical property;polymer chain
研究领域:
材料科学
·
高分子化学
·
流变学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2019
·Vol. 8
·期 12
·606
·
IF 3.011
Hong Peng,Bin Li,Jing Tian
The study explored punicalagin (PGN) as a wheat flour enhancer. The impact of PGN on the physicochemical and structural properties of wheat flour have been investigated. It turned out that PGN increased the formation time, stability, tensile resistance, extension, and viscoelasticity of the dough at the concentrations of 0.13 and 0.26 mg/g. Scan electron microscope images of the cross section of the dough displayed a more compact and ordered network structure with the addition of 0.13 and 0.26 mg/g PGN. Fourier transform infrared spectroscopy spectra indicated an increase of α-helix and β-sheet content. However, nonlinear enhancing effects of PGN on the stretching properties, rheology, and structural properties of the dough were observed at concentrations of 0.39 and 0.52 mg/g. Correspondingly, cleavages were observed on the cross section of the dough and the content of β-sheet showed a trend of reduction in the dough with addition of PGN at high concentrations. Taken together, these results indicated the potential usage of PGN as a wheat flour enhancer of natural origin at the concentration below 0.39 mg/g in the flour.Keywords:punicalagin;wheat flour;dough rheology;gluten protein network
研究领域:
食品科学
·
植物化学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 54
·48810-48815
·
IF 3.289
Ge Yang,Jianxi Zhao
A reverse aggregate system composed of oleic acid and diethylenetriamine in cyclohexane has been studied. Small angle X-ray scattering (SAXS) measurements and polarising microscopy (POM) observations suggested the formation of reverse vesicles. FT-IR measurements showed simple attraction between DETA and OA, which increased the size of the head of the forming unit and resulted in reverse vesicle formation. Therefore, the viscosity of solutions depended on the mole ratios of DETA to OA,β, and reached a maximum of 122 Pa s at β = 1 for 1 mol L−1 OA. Dynamic oscillatory sweeps were carried out for this system of equi-mole mixed OA (1 mol L−1) and DETA. Strong elasticity was observed, where the elastic modulus (G′) always dominated over the viscous modulus (G′′) over the range of examined frequencies. The elastic plateau modulus G′P was 127.4 Pa and G′P was found to decrease exponentially with temperature. Strain sweeps exhibited a strain-softening response at high strains. The effect of trace amounts of water was also examined for equi-mole mixed OA (1 mol L−1) and DETA, where the reverse vesicles remained. The water was found to improve the association of DETA with OA and increase the visco-elasticity of the solution. The maximum viscosity was as high as 6005 Pa s at W0 = 6, and G′P also reached 530 Pa. The solution became gelatinous in appearance.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 121
·100114-100122
·
IF 3.84
Lingling Lei,Zongze He,Huanle Chen,David Julian McClements,Bin Li,Yan Li
Antimicrobial emulgels were fabricated by cross-linking chitosan using cinnamaldehyde (CA) nanoemulsions. The influence of system composition and pH on the properties of the emulgels was characterized using electron and confocal fluorescence microscopy, dynamic shear rheology, and Fourier transform infrared spectroscopy (FT-IR). FT-IR confirmed the occurrence of a Schiff base reaction between chitosan and CA. Rheology measurements helped establish the optimum pH and system composition required to fabricate emulgels. Microscopy provided information about the network structure formed within lyophilized emulgels. The emulgels were shown to have strong antibacterial activity against E. coli and S. aureus.
研究领域:
食品科学
·
材料科学
·
微生物学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）