CHINESE JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 39
·期 3
·327-336
·
IF 3.154
Shi Zhen,Wang Qi,Li Gui-Fei,Shou Yu-Feng,Zong Hong-Jie,Yan Shi-Feng,Zhang Kun-Xi,Yin Jing-Bo
Self-healing hydrogels with the shear-thinning property are novel injectable materials and are superior to traditional injectable hydrogels. The self-healing hydrogels based on 2-ureido-4[1 H ]-pyrimidinone (UPy) have recently received extensive attention due to their dynamic reversibility of UPy dimerization. However, generally, UPy-based self-healing hydrogels exhibit poor stability, cannot degrade in vivo and can hardly be excreted from the body, which considerably limit their bio-application. Here, using poly (l -glutamic acid) (PLGA) as biodegradable matrix, branching α-hydroxy- ω -amino poly(ethylene oxide) (HAPEO) as bridging molecule to introduce UPy, and ethyl acrylate polyethylene glycol (MAPEG) to introduce double bond, the hydrogel precursors (PMHU) are prepared. A library of the self-healing hydrogels has been achieved with well self-healable and shear-thinning properties. With the increase of MAPEG grafting ratio, the storage modulus of the self-healing hydrogels decreases. The self-healing hydrogels are stable in solution only for 6 h, hard to meet the requirements of tissue regeneration. Consequently, ultraviolet (UV) photo-crosslinking is involved to obtain the dual crosslinking hydrogels with enhanced mechanical properties and stability. When MAPEG grafting ratio is 35.5%, the dual crosslinking hydrogels can maintain the shape in phosphate-buffered saline solution (PBS) for at least 8 days. Loading with adipose-derived stem cell spheroids, the self-healing hydrogels are injected and self-heal to a whole, and then they are crosslinked in situ via UV-irradiation, obtaining the dual crosslinking hydrogels/cell spheroids complex with cell viability of 86.7%±6.0%, which demonstrates excellent injectability, subcutaneous gelatinization, and biocompatibility of hydrogels as cell carriers. The novel PMHU hydrogels crosslinked by quadruple hydrogen bonding and then dual photo-crosslinking of double bond are expected to be applied for minimal invasive surgery or therapies in tissue engineering.
研究领域:
生物材料学
·
组织工程学
✓ 已验证
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Kai Huang,Jinshan Yang,Shaoming Dong,Qian Feng,Xiangyu Zhang,Yusheng Ding,Jianbao Hu
The research focuses on fabrication of graphene scaffolds by three-dimensional printing and their anisotropic properties. A novel strategy to prepare printable graphene ink is reported first, and three-dimensional scaffolds with high content (50 wt %) and aligned graphene are achieved by three-dimensional printing. Adequate shear thinning and rheology behavior are required for printable graphene ink to flow through the nozzle smoothly and self-support during the printing process. The scaffolds with different contents and printing parameters exhibit good resolution and good bonding between layers. The alignment of graphene sheets along the direction of flowing can be observed due to the shear stress in the nozzle. When the temperature rises up to 450 °C, electrical conductivities along transvers and longitudinal directions of 50 wt % are enhanced to 479.2 and 425.6 S/m, which are 6.7 and 8.4 times higher than that at room temperature, respectively. The alignment can contribute to the electrical anisotropy of three-dimensional graphene scaffolds. The electrical resistance variations under compression and electrical anisotropy demonstrate the potential application of the graphene scaffolds in electrical device, sensor, especially combined with three-dimensional printing.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiaofang Lv,Chang Li,Yang Liu,Mingguo Peng,Chuanshuo Wang,Qianli Ma,Shidong Zhou,Xiaoyan Li,Bohui Shi,Shangfei Song
Understanding the transportability of silica-sand-containing hydrate slurries is crucial for production safety of non-consolidated natural gas hydrate reservoirs, especially when solid-state fluidization technology is utilized. Despite some research on silica sand and marine sediments’ influence on hydrate formation kinetics, rheological studies are scarce for systems with silica sands. The formation process of cyclopentane hydrates under the coexistence of hydrophilic silica particles and surfactants were observed. The effects of the concentration and particle size of silica sands as well as the water cut and surfactant concentration of emulsion on the rheological properties of hydrate slurries were investigated using a rheometer. The results indicated: (1) Hydrophilic sand aggregates were entrapped in water droplets, indirectly affecting the oil–water contact area due to the increase in water droplet volume, which was conducive to the combination of alkanes and water molecules to form a hydrate shell; silica particles provided nucleation sites at the oil–water interface to promote the adsorption and aggregation of cyclopentane molecules. (2) The synergistic effect of silica sand and surfactants significantly shortened the induction time of hydrates and increased the viscosity of the slurry. As the concentration of silica sand (1 wt%, 5 wt%, 10 wt%) increased, the induction time of hydrate formation decreased by 44.8 min. Within the concentration range below 5 wt%, the viscosity of the slurry increased as the concentration increased, with an amplitude of 13830.7 mPa·s. The induction time of hydrate formation decreased with increasing silica sand particle size (2 μm, 6.5 μm, 12 μm), but the size of silica sand particles had no significant effect on the viscosity of the slurry. (3) Hydrate slurries in all systems exhibited shear-thinning behavior. There was no obvious relationship between the yield stress of slurry under different silica sand concentrations. However, the yield stress of the slurry was inversely proportional to the size of silica sand particles. The yield stress decreased by 141.13 Pa when the size of silica sand particles increased from 2 μm to 12 μm. Overall, this study highlighted the influence of silica sand presence on flow safety assurance in solid-state fluidization technology.
研究领域:
石油工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Hailong Liu,Nuo Zheng,Jiaqi Chen,Ding Yang,Junfeng Wang
The control of a droplet bouncing on a substrate is of great importance not only in academic research but also in practical applications. In this work, we focus on a particular type of non-Newtonian fluid known as shear-thinning fluid. The rebound behaviors of shear-thinning fluid droplets impinging on a hydrophobic surface (equilibrium contact angle θeq ≈ 108°and contact angle hysteresis Δθ ≈ 20°) have been studied experimentally and numerically. The impact processes of Newtonian fluid droplets with various viscosities and non-Newtonian fluid droplets with dilute xanthan gum solutions were recorded by a high-speed imaging system under a range of Weber numbers (We) from 12 to 208. A numerical model of the droplet impact on the solid substrate was also constructed using a finite element scheme with the phase field method (PFM). The experimental results show that unlike the Newtonian fluid droplets where either partial rebound or deposition occurs, complete rebound behavior was observed for non-Newtonian fluid droplets under a certain range of We. Moreover, the minimum value of We required for complete rebound increases with xanthan concentration. The numerical simulations indicate that the shear-thinning property significantly affects the rebound behavior of the droplets. As the amount of xanthan increases, the high shear rate regions shift to the bottom of the droplet and the receding of the contact line accelerates. Once the high shear rate region appears only near the contact line, the droplet tends to fully rebound even on a hydrophobic surface. Through the impact maps of various droplets, we found that the maximum dimensionless height Hmax* of the droplet increases almost linearly with We as Hmax* ∼ αWe. In addition, a critical value Hmax, c* for the distinction between deposition and rebound for droplets on the hydrophobic surface has been theoretically derived. The prediction of the model shows good consistency with the experimental results.
研究领域:
流体力学
·
材料科学
·
界面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICS OF FLUIDS
·
2024
·Vol. 36
·期 1
·
IF 4.1
Yu Jia-Jia,Jiang Lu-Yang,Huang Li,Li Gu-Yuan,Bake Maitiniyazi,Li You-Rong
Hydrodynamic cavitation, which occurs when the local pressure is below the saturated vapor pressure in hydrodynamic flow, is ubiquitous in fluid dynamics and implicated in a myriad of industrial and biomedical applications. Although extensively studied in isotropic liquids, corresponding investigations in anisotropic liquids are largely lacking. In this paper, the hydrodynamic cavitation in the bluff body bypass flow of nematic liquid crystal 5CB in the microchannel is experimentally investigated. By 5CB, we mean the thermotropic liquid crystal 4′-pentyl-4-biphenylcarbonitrile. When the Reynolds number is in the range of 3 × 10 −4 < Re < 1.2 × 10 −3 , a special flow phenomenon behind the bluff body is observed, namely, the disclination loop. The critical Reynolds number of cavitation inception varies with the shape of the bluff body, while the lowest value corresponds to the triangular bluff body. The hydrodynamic cavitation occurs in the Stokes flow regime with the Reynolds number significantly lower than 0.1 for all bluff bodies. There is a close relation between the oscillation behavior of cavitation domains and the structure of the bluff body. In addition, the pressure difference between the inlet and outlet of the microchannel shows linear relation with the Reynolds number rather than the quadratic relation for isotropic fluids, which proves the presence of shear thinning in the flow of nematic liquid crystals. The study in this paper on the hydrodynamic cavitation of nematic liquid crystal can broaden the research on providing new approaches for the enhancement of fluid mixing and heat transfer in microfluidic chips.
研究领域:
流体力学
·
材料科学
·
微流控技术
✓ 已验证
产品关联
DOI
高影响因子
KOREA-AUSTRALIA RHEOLOGY JOURNAL
·
2024
·
IF 2.2
Yang Ding,Chen Jiaqi,Shen Ao,Wang Junfeng,Liu Hailong
The spreading behavior of droplets impacting solid surfaces is of significant importance in numerous industrial and medical applications. This study specifically focuses on the droplet impact behaviors of shear-thinning fluids. Extensive impact experiments were conducted using high-speed visualization techniques. Image sequences in the DI water and xanthan gum solution droplets impact process are captured at a We range of around 3.2–388 and Re n of 18–8145. The morphologies of spreading droplets on hydrophilic, moderate, and hydrophobic surfaces was observed with temporal evolution. The experimental results showed that the spreading behavior of shear-thinning droplets varies with the impact velocity, surface wettability, and fluid concentration. The droplets spread more widely and rapidly at larger We with the time evolution of the spreading factor. In addition, the spreading of the droplets becomes suppressed on a hydrophobic surface or with a higher xanthan concentration. With the increase of We , the effect of fluid viscosity gradually surpasses the surface wettability. The fluid viscosity with the shear-thinning properties has more influence on the spreading behavior at high We . Furthermore, the experimental data of the maximum spreading factor could be scaled with the We and Re n at low and high We , respectively. Finally, the maximum spreading of shear-thinning droplets was correlated with a universal rescaling model. The correlation shows good accordance with the experimental results of droplet impact from this study and the literature in a wide range of impact conditions and shear-thinning properties. Graphical abstract
研究领域:
流体力学
·
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Linqiang Wang,Jiabao Feng,Hong Zhu,Yadong Lv,Qi Yang,Guangxian Li,Miqiu Kong
With the progression of electronic components toward high performance, miniaturization, integration, and increased power, efficient heat dissipation has become essential for maintaining performance and extending service life. To address this significant academic and industrial challenge, thermal interface materials (TIMs) with high thermal conductivity are indispensable. This study presents a bottlebrush polymer with a polymethylvinylsiloxane backbone grafted with octadecanethiol side chains (PMVS-ODT), utilized in conductive PMVS-ODT/Al 2 O 3 composites. These composites demonstrate superior thermal conductivity, improved thixotropy, and low contact thermal resistance ( R c ), outperforming conventional PDMS/Al 2 O 3 composites. The low-viscosity bottlebrush PMVS-ODT can compounded with Al 2 O 3 through a simple and scalable mechanical blending process, enabling Al 2 O 3 loadings as high as 87.8 vol.%. Strong interactions between PMVS-ODT and Al 2 O 3 , along with the compliance and thixotropic properties of PMVS-ODT/79.4 vol.% Al 2 O 3 composites, enhance the thermal conductivity to 8.181 W/(m·K) and reduce the R c to 20.9 mm 2 K/W (20 psi). These results represent increases of 79.9% and decreases of 64.6%, respectively, compared to traditional PDMS/Al 2 O 3 composites. Additionally, significantly enhanced thermal management performance is demonstrated for PMVS-ODT/Al 2 O 3 composites when applied as heat dissipation materials for computer CPUs and LED light modules. This matrix structure design offers an effective strategy for developing high-performance polymer-based TIMs suitable for next-generation advanced electronic applications.
研究领域:
材料科学
·
高分子化学
·
热管理工程
✓ 已验证
产品关联
DOI
高影响因子
EXPERIMENTAL THERMAL AND FLUID SCIENCE
·
2024
·
IF 2.8
Lijuan Qian,Liujun Xu,Chengbin Sun,Li Lv
The surface and droplet characteristics significantly affect the dynamic of droplet impact on solid surfaces. In present work, a platform is utilized to experimentally study the dynamic behavior of shear thinning fluid droplets impacting superhydrophobic spheres, where the effects of different concentrations, Weber numbers ( We ), particle size ratios on droplets impact are studied. The results showed that on the superhydrophobic sphere, as the shear thinning droplet concentration increases, the diffusion diameter increases, and the contact time decreases. For the same curvature, the contact time between the droplet and the sphere decreases with the increase of the We . When the We reaches 75 or above, the contact time remains constant with an increase in the We . For various curvature conditions, the contact time increases as the curvature increasing. When the diameter ratio of the sphere to the droplet is D ∗ ≥ 6 , the maximum diffusion coefficient remains almost constant. However, when D ∗ < 6 , the maximum diffusion dimensionless diameter significantly increases as the particle size ratio decreases. More importantly, a theoretical model considering gravity effect is presented to predict the maximum dimensionless diameter of shear thinning droplets on superhydrophobic spheres according to energy conservation. The predicted results are rationally agreement with experiments with the deviation within ±10 %.
研究领域:
流体力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Developments in the Built Environment
·
2025
·
IF 8.2
Jian Zhang,Zhenming Li,Wentao Wang,Yaxin Tao,Yubo Sun,Xiangsheng Chen
Alkali-activated materials (AAMs) emerge as a sustainable alternative to Portland cement binders. Despite their potential, the rheological properties of alkali-activated concrete, particularly their non-linear behaviors, remain underexplored. To bridge this gap, a comparative study was conducted to examine the flow characteristics and shear thinning/thickening tendencies of alkali-activated slag (AAS) concrete. The research began with a detailed evaluation of the setting times of AAS mixtures, optimizing activator compositions to identify formulations suitable for concrete productions. Employing the Bingham and Herschel-Bulkley models, it was observed that AAS concrete with a lower silicate modulus (Ms) predominantly exhibited shear-thinning behavior. As the Ms increased, a shift toward shear-thickening behavior occurred, becoming more pronounced with higher concentrations of alkaline compounds in the activators. Furthermore, the fresh properties of AAS concrete significantly improved with increased alkali dosages in the activators, resulting in reduced dynamic yield stress and plastic viscosity, along with enhanced workability retention over time.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2021
·Vol. 68
·期 1
·e17395
·
IF 3.993
Xiyang Liu,Ziwei Liu,Shaokun Jiang,Chunying Zhu,Youguang Ma,Taotao Fu
In this paper, the formation mechanism of droplets of shear-thinning non-Newtonian fluids in a step-emulsification microdevice is studied experimentally, by using aqueous solutions of sodium carboxymethyl cellulose (CMC) as the dispersed phase and cyclohexane as the continuous phase. According to the evolution of the front-end length of the dispersed thread over time, the droplet generation process is divided into three stages: the two-dimensional expansion stage, the three-dimensional rapid expansion stage, and the necking stage. The influence of the dispersed phase flow rate Q d and CMC concentration c on droplet formation is described. The results show that the addition of CMC in the aqueous solution increases the viscosity of the dispersed phase and slows down the evolution of the dispersed phase, thereby resulting in the increase of the droplet size. Finally, a droplet volume prediction model considering non-Newtonian characteristics is proposed, and the formation of satellite droplets is analyzed.
研究领域:
流体力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Ying Liu,Hengfei Liang,Zihong Zhang,Chengyao Hu,Hui Yan,Yawen Huang
The application of self-healing polymers in anti-corrosion coatings is restricted by their nonautonomous healing ability and poor long-term durability. In this paper, we propose a functional partition strategy assisted by the shear thinning effect to overcome the above restriction. The shear thinning effect was achieved by preparing a branched ethyl acrylate-acrylonitrile copolymer (B-PEA). The B-PEA coating exhibits multiple autonomous self-healability at room temperature (1.5 h) and in a salt solution (2 h), with a high adhesion strength of 3.4 MPa. To further improve the performance, a functional partition architecture combining superhydrophobic barrier and self-healing multilayers was constructed. The introduction of the superhydrophobic barrier layer largely increases the low-frequency impedance modulus | Z | f-0.01Hz and salt solution resistance time to 3.9 × 10 10 Ω⋅cm 2 and 3600 h, respectively, compared to a pristine B-PEA coating. The introduction of the B-PEA layer provides the barrier layer with room-temperature self-healing ability (2 h), and increases the long-term | Z | f-0.01Hz and salt solution resistance time in the presence of scratches to 7.7 × 10 9 Ω⋅cm 2 and > 3600 h, respectively. The as-prepared superhydrophobic anti-corrosion coating system combines long-term durability and room-temperature autonomous self-healability in harsh salt-solution environments, and thus has a high potential for anti-corrosion applications.
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
FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Yang Zhao,Qingcheng Wang,Tian Liu,Peipei Wang,Igor S. Makarov,Mohammad Rizwan Khan,Jiaqi Guo,Wenyuan Zhu,Huining Xiao,Junlong Song
An emulsion stabilization technique based on molecularly thin cellulose nanoribbons (CR) is described, demonstrating superior emulsifying capability at concentrations as low as 0.05 %. The results show that CR enables the stabilization of oil-in-water emulsions that remain stable for over 60 days, even at high oil-to-water ratios. Rheological assessment reveals a shear-thinning profile and dominance of storage modulus (G') over loss modulus (G"), signifying the emulsions' viscoelastic nature and resistance to structural breakdown. In particular, emulsions containing 0.5 % CR presented exceptional centrifugal stability at 8000 rpm without oil leakage or emulsion breakage. In contrast, emulsions stabilized by cellulose nanocrystals (CNC) and nanofibrils (CNF) exhibited significantly reduced stability and viscosity. This study underscores CR's potential in creating eco-friendly, high-performance food-grade emulsions that meet the burgeoning demands for environmentally friendly and healthy foods.
研究领域:
食品科学
·
材料科学
·
化学工程
✓ 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）