CEMENT AND CONCRETE RESEARCH
·
2023
·
IF 11.4
Xinming Wang,Jing Zhong
When GO suspension is mixed with cement, different GO dispersion states exist, including well-dispersed state (WDS), grain-adsorbed state (GAS), and self-agglomerated state (SAS). Although the seeding effect mechanism of GO in WDS is well accepted, how GO in GAS and SAS impacts hydration is still an open question. In this study, we selectively studied the effects of GAS and SAS on tricalcium silicate (C 3 S) hydration. The results revealed that GO in GAS limits the accessibility of reactant for hydration at early age, without notably affecting the subsequent hydration. Instead, GO in SAS strongly absorbs calcium ions from pore solution to significantly decrease its over-saturation degree, which results in more tightly compacted hydrates formed on C 3 S surface and thus inhibits hydration. These results lead to an improved understanding of GO in cement hydration , and help us unlock the potential of GO in cementitious materials .
研究领域:
材料科学
·
土木工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Zhaofu Wang,Rong Qi,Jin Wang,Shuhua Qi
The introduction of highly thermally conductive expanded graphite in polymers can functionally improve the thermal conductivity of epoxy resins. In this study, expanded graphite particles were thus introduced into an epoxy polymer matrix via solution blending method with ultrasonic procedure in order to improve the thermal conductivity of the epoxy matrix. The thermal conductivity of epoxy composites was analyzed by laser flash method. The dispersive status of the fillers was characterized by scanning electron microscope (SEM). The thermal stability of the composites was investigated through Thermo-gravimetric analysis (TGA). The results show that the thermal conductivity of epoxy resins increases significantly due to the addition of EG(expanded graphite) particles. As a matter of fact, the thermal conductivity of epoxy composites increases with the increase of EG particles loading from 0 wt% to 4.5 wt%. The distribution of EG particles in the matrix greatly affects the thermal conductivities of epoxy composites. The thermal conductivity of (KH550@EG)/epoxy composites is greatly improved compared with untreated EG/epoxy composites. The thermal conductivity value of the composites at 4.5 wt% loading obtained by experiment is 1.0 W/(m K) with a thermal decomposition temperature improved to 348 °C from 318 °C of pure epoxy.
研究领域:
材料科学
·
热物理学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Xiaomeng Li,Shuxue Zhou
Utilization of Ti 3 C 2 nanosheets for enhancing anticorrosion of epoxy resin coatings has been reported. But the epoxy coatings in real world are mainly pigmented coatings. Unfortunately, the anticorrosion behavior of Ti 3 C 2 nanosheets for the pigmented epoxy coatings is rarely concerned. In this work, both 0.5 wt% unmodified Ti 3 C 2 nanosheets (U-Ti 3 C 2 ) or 0.5 wt% (3-glycidyloxypropyl)trimethoxysilane-modified Ti 3 C 2 nanosheets (G-Ti 3 C 2 ) were introduced into solvent-based titania pigmented epoxy coatings. Corrosion resistance of coatings was evaluated by electrochemical impedance spectroscopy and salt spray tests. A titania concentration effect was interestingly exhibited for the anticorrosion behavior Ti 3 C 2 -containing pigmented coatings. Enhanced anticorrosion was only demonstrated when TiO 2 content was not above 10 wt% for U-Ti 3 C 2 or 5 wt% for G-Ti 3 C 2 . Moreover, the pigmented coatings with U-Ti 3 C 2 have better corrosion resistance than those with G-Ti 3 C 2 , being contrary to the phenomenon observed in pure epoxy resin coatings. The different anticorrosion behavior of Ti 3 C 2 nanosheets for epoxy coatings with various TiO 2 contents was mainly attributed to the different dispersion states of TiO 2 pigments, that is, improved dispersion at low TiO 2 content and deteriorated dispersion at high TiO 2 content, after addition of Ti 3 C 2 nanosheets.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2024
·
IF 2.6
Chen Wang,Li Wenxin,Jiang Jiahao,Yao Changyu,Li Li,Gao Hanyang
Silicon nanomaterials have received much attention due to their ability to adapt to large volume changes and thus avoid fragmentation. Studies have shown that two-dimensional flaky silicon particles (F–Si) have better mechanical stability than spherical silicon particles (S–Si), but the larger specific surface area of flaky silicon highlights the problem of chemical stability. A suitable binder can stabilize the surface of the silicon particles through interaction with the silicon particles. This work is a comparative study of various binder systems for S–Si and F–Si: sodium carboxymethyl cellulose (CMC), polyacrylic acid (PAA), and sodium alginate (SA). The relationships between the rheological properties of the electrode slurry, the functional group states of the silicon particles and electrode coatings, the state of the dried electrode surface, and the type of binder were investigated. The experimental analysis shows that CMC and SA as rigid binders exhibit better cycling performance in S–Si/F–Si electrodes due to their better dispersion states. The dispersion of S–Si electrodes with higher silanol (Si–OH) content is dominantly influenced by electrostatic repulsion, and that of F–Si electrodes with lower Si–OH content is dominantly influenced by bridging. The experimental analysis demonstrates that CMC and SA as rigid binders exhibit better cycling performance in S–Si/F–Si electrodes, respectively, due to their better dispersion states. The dispersion of S–Si electrodes with higher silanol Si–OH content is dominantly influenced by electrostatic repulsion, and that of F–Si electrodes with lower Si–OH content is dominantly influenced by bridging.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2014
·
IF 3.633
Yicheng Wu,Zhiqiang Yu
The incorporation of highly thermally conductive ceramic materials in polymers could improve effectively the thermal conductivity of polymer matrix . In this work, Zirconium diboride (ZrB 2 ) particles with high thermal conductivity were introduced into an epoxy polymer matrix by in situ synthesis method for the improvement of thermal conductivity of epoxy matrix . The thermal conduction of epoxy composites was investigated by laser flash method and numerical analysis. The dispersive status of the fillers was characterized by transmission electron microscopy (TEM). The results showed that the thermal conductivities of epoxy resin were increased significantly due to the addition of ZrB 2 particles. The thermal conductivity of epoxy composites increases with the increase of ZrB 2 particles loading ranging from 0 wt% to 16 wt%. The enhancement of thermal conductivity exhibited a little change when the particles content exceeded 12 wt%. The influence of the temperature on the improvement of thermal conductivity was inconspicuous. The thermal conductivity of ZrB 2 /epoxy composites increased slightly with the increase of temperatures in the range of 25–100 °C. The distribution of ZrB 2 particles in the matrix affected the thermal conductivities of epoxy composites greatly. In comparison, the composites with 12 wt% ZrB 2 particles loading presented better dispersion of the particles in the epoxy matrix than those of the other composites. The thermal conductivity values of the composites at 12 wt% loading obtained by finite-element analysis (FEA) were in good agreement with the experimental value.
研究领域:
材料科学
·
热传导工程
✓ 已验证
DOI
高影响因子
NANO
·
2015
·
IF 1.09
YAN WANG,YAOFENG ZHU,YAQIN FU
A novel shear thickening fluid (STF) obtained from a halloysite nanotube (HNT) and SiO 2 compounded system was successfully prepared using HNT and nano- SiO 2 as dispersed phases and polyethylene glycol 200 (PEG200) as the dispersion medium. The steady rheological behavior of the STF was investigated using a high-speed rotational rheometer, and the dispersion states of SiO 2 and HNT in PEG200 were characterized by field emission scanning electron microscopy and transmission electron microscopy. Results show that HNT and SiO 2 coexisted in the compounded system, and presented a special state that was both uniformly dispersed and partially enriched. The shear thickening effect of the STF was significantly enhanced by the enrichment of SiO 2 loaded on the surface of HNTs in the compounded system.
研究领域:
材料科学
·
流变学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Dongming Qi,Feng Gao,Zhijie Chen,Zhonglan Cui,Gang Wang,Ningning Wang,Yushan Zhang,Gan Qu,Zhihai Cao
Dispersion state of inorganic nanoparticles (NPs) in the composite films may significantly influence on the film properties. In the present study, polymer/SiO 2 nanocomposite particles (NCPs) with various SiO 2 grafting states (various grafting ratios, various linking patterns between SiO 2 NPs, and various types of grafted chains), were prepared through in situ emulsion or in situ miniemulsion technique. These NCPs were used as building blocks to prepare composite films. The microscopic observations and surface composition analyses of the composite films manifest that the spatial distribution of SiO 2 NPs in the composite films depends on the baking temperature, SiO 2 grafting state, and the compatibility between SiO 2 NPs and polymer matrix. The SiO 2 NPs might display a cluster-like distribution, homogenous one, or locally aggregated one. The results from this study demonstrate how the grafting state of inorganic NPs is effective in controlling dispersion state of inorganic NPs and further determining the properties of composite films.
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
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 6
·5149-5159
·
IF 2.993
Chen Kexu,Kang Ming,Lu Ai,Chen Lin,Song Lixian,Sun Rong
The internal dispersion structure of silica fillers in polymer matrix is significant for design and fabricating high-performance polymer composite. In order to explore the relationship between fillers spatial dispersion states and mechanical properties, we use superficial fluorescent labeling to achieve fillers visualization in polymer matrix with laser scanning confocal microscopy. Through the effect of fluorescent silane coupling agent, the uniform red fluorescence characteristics were shown on the silica surface. The 2D-planar and 3D-spatial dispersion states of silica fillers in rubber matrix can be accurately observed with fluorescence imaging technology. The results by Avizo software statistics show that high-content silica fillers in composite tend to undergo dissociation of aggregates. These dissociated small volume aggregates which facilitate the interaction between particles and rubber matrix to dissipate mechanical energy effectively and rapidly improve rubber toughness. This successful visualization method opens a new avenue in spatial dispersion description of fillers aggregates in organic–inorganic composite.
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
POLYMER COMPOSITES
·
2019
·Vol. 41
·期 4
·1605-1613
·
IF 2.268
Xiangmeng Lv,Ming Kang,Lu Yuan,Simin Shen,Rong Sun,Lixian Song,Shangjun Zeng,Meng Yin
The dispersion state of fillers in the polymer matrix is an important factor to determine the properties of the polymer composites. Here, a new method for the accurate quantitative evaluation dispersion state of fillers through three-dimensional (3D) visualization and fractal analysis is reported. First of all, the data model of the dispersed state of the fillers is obtained through 3D visualization techniques. Then the fractal dimensions of different samples are obtained by software based on the fractal theory. As the filler increases, the fractal dimension is firstly decreases to a minimum and then increases. Under this extreme point condition, the theoretical dispersion state of the fillers is uniform. The accurate quantitative description of the dispersion state provides a new basis for establishing the relationship between the dispersion state and the mechanical properties of the fillers in various composites.
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
MATERIALS AND STRUCTURES
·
2022
·Vol. 55
·期 1
·1-15
·
IF 4.285
Wang Xiaonan,Feng Decheng,Zhong Jing,Shi Xianming
The investigations on reduced graphene oxide (rGO) or graphene as an additive for cement reinforcement is relatively limited. Previous studies either employed thick graphene nanoplates, obscuring the flexible nature of graphene, or involved toxic agents, hindering their practical applications. Interestingly, in spite of the importance of uniform dispersion, there is still no method for quick and effective evaluation of the dispersion quality of rGO in both water and pore solution. Here, we prepare high-quality rGO by green chemical reduction of graphene oxide, followed by thorough washing without drying. The dispersion quality of rGO was assessed by dynamic light scattering, transmission electron microscopy, as well as morphological characterization of rGO film prepared by filtration. Because of water depletion by cement hydration, rGO agglomeration in pore solution is inevitable even for 0.05 wt% rGO/cement nanocomposites. This work shows that the compressive and flexural strength of a cement paste at 28 days were enhanced by 16.5% and 20.9% by admixing 0.05 wt% rGO, corresponding to very high reinforcement efficiency of 330% and 418%, respectively. Interestingly, the extremely low concentration (0.01 wt%) of rGO resulted in a decrease of flexural strength of cement paste. This is probably attributable to the flexibility of rGO nanosheets, which allows rGO to conformally wrap cement particles and affect its hydrated microstructure. Therefore, a minor level of rGO agglomeration is likely beneficial to the effective reinforcement of cementitious material by rGO, and the effect of nanosheets encapsulating the reactive particle or its matrix should be considered.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR SYMPOSIA
·
2025
·Vol. 414
·期 4
·e70085
·
IF 0
Chenjun Zhang,Xi Zhang,Xiaodan Liu,Yiheng Li,Xiaoqi Wang,Xu Jin,Man Shen,Lanqiong Zhang
Specialty engineering rubber has been put forward with more stringent requirements. In this paper, the material properties and reinforcing effects of several fillers were investigated, and polyamide was selected as the target reinforcing material to modify hydrogenated nitrile butadiene rubber (HNBR) in order to improve the temperature resistance of the system. It was concluded that the mechanical properties of PA1212/HNBR system were better than those of PC/HNBR system at 120°C. The optimum PA1212 additive amount was determined through the mechanical property test and dispersion state observation of the blended system, which proved that the PA1212 reinforcing system significantly improved the heat resistance and mechanical properties of HNBR. The modified HNBR has excellent tensile strength and elasticity, which effectively improves the reliability and service life of the sealing equipment under high temperature conditions, and provides experimental references and theoretical basis for the research and development of high-temperature resistant rubber.
研究领域:
材料科学
·
高分子科学
·
机械工程
·
化学工程
✓ 已验证
产品关联
DOI
Progress in Natural Science-Materials International
·
2018
·
IF 2.572
Ruijie Zhao,Jiale Xu,Peng Tao,Fenglei Shi,Fan Yu,Xiaoliang Zeng,Chengyi Song,Jianbo Wu,Wen Shang,Tao Deng
With the increased need for clean water and decreased supply of fresh water, purification of contaminated water can provide clean water that supplements the fresh water from nature. Physical adsorption, photo-degradation and solar-driven evaporation processes are promising ways to generate clean water with minimum environmental impact. However, different purification process requires different dispersion state of the treating agent to maximize its performance. Herein, we demonstrate that Fe 3 O 4 -reduced graphene oxide (MrGO) particles with switchable dispersion can be used as the multifunctional water treating agents to efficiently purify contaminated water through different processes. Under homogenously dispersed nanofluid mode, the MrGO particles have large exposed surface areas and can efficiently remove organic dye pollutants through physical adsorption. The uniform dispersion state also favors high contact efficiency facilitating decontamination of high concentration of organic compounds through solar-driven photocatalytic degradation by the MrGO particles. The excellent magnetic response of MrGO particles not only allows for easy collection of the treating agent from water but also enables assembly of MrGO at the air-water interface with external magnets. Under such interfacial assembled mode, clean water can be distilled out of the contaminated solution with high evaporation efficiency of 74.7% under simulated natural solar radiation. This work demonstrates that dispersion state can be used as another important means to optimize water purification performances.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）