JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2020
·Vol. 103
·期 11
·6505-6518
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IF 3.502
Pengkun Hou,Xinming Wang,Piqi Zhao,Kejin Wang,Shiho Kawashima,Qinfei Li,Ning Xie,Xin Cheng,Surendra P. Shah
In this paper, C 3 A-gypsum and C 3 A-C 3 S-gypsum model cement systems with and without nanosilica were studied. The effects of nanosilica on the early stage cement hydration, particularly C 3 A hydration, were assessed through the heat of hydration (isothermal calorimetry), phase assemblage (quantitative X-ray diffraction), zeta potential, ion concentration measurements, and morphology (scanning electron microscopy) examinations. The results indicate that while promoting C 3 S hydration, nanosilica retarded C 3 A hydration in both the systems studied. The retardation was caused by the adsorption and coverage of nanosilica on C 3 A surfaces through the electrostatic interaction, thus decreasing the C 3 A dissolution rate and hindering the precipitation of hydration products. Consequently, the reduced gypsum consumption rate and the seeding effect of nanosilica further promoted C 3 S hydration. These findings suggest that nanosilica and other silica-based nanoparticles can physicochemically influence hydration of cement-based materials, and a better understanding of these influencing mechanisms can help optimize performances of nanoparticle-modified cement-based materials.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 5
·1176-1185
·
IF 0.524
Lu Guosen,Deng Min,Mo Liwu
C3S pastes containing 0%, 5%, 10%, and 15% nano-SiO2 mixed with de-ionized water and alkali solutions were prepared. When C3S was completely hydrated, the pastes were ground into powders with a particle size less than 80 μm. Adsorption and desorption characteristics of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water immersed in alkali solutions and those in C 3 S-nano SiO 2 pastes mixed with alkali solutions, were investigated. Meawhile, the adsorption mechanisms of alkali ions were discussed. Results showed that the contents of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO 2 and/or the initial alkali concentrations. In C 3 S-nano SiO 2 pastes mixed with de-ionized water, each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration. No obvious difference between the adsorption capacity of a given paste for K + and Na + was observed. Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste, and charge compensation of C-S-H gel, mainly by electrostatic interactions. In C 3 S-nano SiO 2 pastes mixed with alkali solutions, alkali ions may enter the structure of C-S-H gel to replace a part of Ca 2+ in the interlayer. This assumption is supported by the structural characterization of C-S-H gel using 29 Si MAS NMR.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2024
·
IF 10.8
Aofei Guo,Danying Gao,Zhihui Sun,Hu Feng,Zhenyun Yu,Zeyu Guo,Hong Shang,Fengjuan Liu
Tricalcium silicate (C 3 S) is the primary ingredient in ordinary Portland cement (OPC). Understanding the hydration kinetics of C 3 S with cellulose nanocrystals (CNC) is the key to unveiling the intrinsic mechanism of CNC affecting OPC hydration . This study investigates the hydration interactions between C 3 S and CNC through extensive testing. Findings indicate that CNC incorporation can initially slow the hydration reaction and postpone the early-stage hydration of C 3 S. However, past the initial period (3 days in this study), CNC presence enhances the hydration pace and aids the hydration process , leading to an increase in the formation of calcium silicate hydrate (C–S–H) and calcium hydroxide (CH) without creating new phases. Further, the presence of CNC promotes the homogenous hydration of C 3 S, ensuring a homogenous distribution of hydration products . It also reduces the Ca/Si ratio in the C–S–H, without altering the C–S–H morphology. A correlation is made between heat flow and the thickness of hydration products enveloping C 3 S particles, confirming that CNC can intensify the inward water diffusion rate through C 3 S particles for the same hydration product thickness. Critically, it is found that the effect of CNC on C 3 S hydration is dependent on the water/C 3 S ratio. A low or moderate water/C 3 S ratio can promote C 3 S hydration but a very high water/C 3 S ratio diminishes the beneficial effects of CNC on C 3 S hydration. Finally, the study proposes a explanation for CNC's influence over the hydration of C 3 S with varying water/C 3 S ratios.
研究领域:
材料科学
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化学工程
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高影响因子
Materials
·
2024
·Vol. 17
·期 21
·5364
·
IF 3.1
Lihui Li,Kaiming Niu,Jianrui Ji,Panpan Zhang,Jilin Zhang
In order to impart the properties of cementitious material to the Tibetan Agar soil, two high-temperature activation mechanisms (HTMA, HTMB) were designed in this study, and the products and hydration-hardening properties of Tibetan Agar soil high-temperature activation mechanism were analyzed by means of SEM, XRD, and XRF. The results show that the main components of Tibetan Aga soil are calcite and quartz; Aga soil is activated by HTMA high-temperature activation, forming the main products of CaO, C2S, CaSiO3, and CaAl2Si2O8, and its products have both air-hardening and water-hardening characteristics; Aga soil is activated by HTMB high-temperature activation, and when the temperature reaches 1250 °C when the clinker is not found in the CaO, the generation of C2S, C3S, C3A, C4AF, and Mg2SiO4minerals with good water-hardening cementitious properties occurs when the temperature rises to 1350 °C, although the formation of some inert minerals that do not have the cementitious properties, but this temperature activation products of the thermodynamic properties of the best; Enhancing the value of lime saturation degree (KH) and silicon rate (SM) can promote the formation of the products of the C2S and C3S, increase the reactivity of the Aga soil activation products, and increase the hydration heat as well as compressive and flexural strength, combined with the results of the hydration heat and mechanical test, KH is recommended to be 0.9~0.94, SM is recommended to be 1.8~2.4, and alumina ratio (IM) is recommended to be 1.8~2.4 when Aga soil is used with raw materials.
研究领域:
材料科学
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土木工程
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DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Jihong Jiang,Han Wang,Junlin Lin,Zhiyong Liu,Laibo Li,Yali Li,Zongjin Li,Lingchao Lu,Yunjian Li,Zeyu Lu
Previous studies primarily considered TiO 2 as a nano-filler to accelerate cement hydration due to the nucleation site effect. However, hydroxyl free radicals (•OH), released from TiO 2 under UV irradiation, also exhibit great potential to accelerate cement hydration owing to their high nucleophilicity arising from unpaired electrons. This study is the first to reveal the accelerating mechanism of •OH generated by photoexcited nano-TiO 2 on cement hydration. Current experimental results indicated that 5.0 wt% addition of photoexcited nano-TiO 2 (under 6 h of UV irradiation during the early curing stage) improved the dissolution rate of tricalcium silicate (C 3 S) by 30 %, followed by a 35 % increase in the hydration degree of cement paste. More importantly, the polymerization degree and high-density content of C–S–H gels were also improved by 26 % and 13 %, accompanied by a 46 % reduction in porosity of the composites. All the aforementioned improvements were attributed to the presence of •OH generated by photoexcited nano-TiO 2 , which significantly accelerated cement hydration by accelerating C 3 S dissolution, facilitating faster nucleation and growth of C–S–H gels. In addition, the Density Functional Theory (DFT) calculations revealed that the accelerating effect of •OH on cement hydration may stem from the stronger interaction between •OH and the Ca ion on the C 3 S surface compared to the water molecule, and the increased surface nucleophilicity due to the dispersion of unpaired elections from •OH to all the O ions in the surface layer. These findings provide a high-efficiency approach to accelerate cement hydration by photoexcited nano-TiO 2 , thereby paving the way for the development of advanced and sustainable cement-based materials.
研究领域:
材料科学
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化学工程
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高影响因子
MATERIALS AND STRUCTURES
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2022
·Vol. 55
·期 7
·1-17
·
IF 4.285
Wang Xiaonan,Feng Decheng,Shi Xianming,Zhong Jing
Understanding the fundamental role of carbon nanomaterials is the key to unlocking their potential in enhancing the macroscopic engineering properties and performance of cementitious materials. There is significant debate over the hypothesis that carbon nanomaterials with high surface areas could promote cement hydration by providing nucleation sites (i.e., seeding effect). The seeding effect of carbon nanotubes (CNTs) for cement hydration has lacked direct experimental evidence, mainly due to the inability to directly observe the surface of CNTs after their full contact with the pore solution of cement and the complexity of hydration products at the nanoscale. Different from previous studies, we developed CNT sponge (CNTSP), a macro-scale assembly consisting of randomly oriented and entangled CNTs in three-dimension space, as the platform for discriminating the potential nucleating effect of CNTs. By design, the CNTSP features nano-sized interconnected pores that allow only the pore solution to penetrate through, thus separating the tricalcium silicate (C 3 S) particles and the pore solution of C 3 S in situ. The experimental results revealed that pristine and oxidized CNTs could barely act as seeding material for the nucleation of C 3 S hydration products. Relative to pristine CNT, oxidized CNT can promote the local formation of calcium hydroxide (CH) that is only loosely connected to the CNT, while depressing that of calcium silicate hydrate (C–S–H). The CNTSP was further employed as a platform to investigate the effects of superplasticizer on C 3 S hydration, revealing that the superplasticizer improves the CNT-hydrates binding. This work not only provides fundamental knowledge about the limited role of CNT in C 3 S hydration, but also demonstrates a novel experimental platform for investigating the interaction between carbon nanomaterials and cement hydration products.
研究领域:
材料科学
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土木工程
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纳米技术
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DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2022
·
IF 6.267
Liguo Wang,Yu Zhang,Le Guo,Fengjuan Wang,Siyi Ju,Shiyu Sui,Zhiyong Liu,Hongyan Chu,Jinyang Jiang
Studying the mechanism by which organic admixtures affect the hydration and dissolution of tricalcium silicate (C 3 S) reveals the effect of organic admixtures on ordinary Portland cement and enables target regulation of cement-based materials. In this study, the effects of citric-acid-modified chitosan (CAMC) on the hydration exotherm, hydration products, and microscopic morphology of C 3 S were investigated. The interface structures, ion adsorptions, and dissolution properties of CAMC and C 3 S were analyzed using a molecular dynamics simulation method. The results showed the presence of an attraction between the C 3 S surface and CAMC due to the existence of O p -H w , O p -Ca s , and H p -O w ion pairs. CAMC adsorbed most of the Ca ions released upon dissolution of C 3 S in the aqueous solution and the resulting pairs exhibited low solubilities. The Ca ions were located on the surfaces of C 3 S particles, preventing the dissolution of the particles and proving the interference effect of additives on the hydration of the cement silicate phase.
研究领域:
材料科学
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化学工程
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高影响因子
Materials
·
2024
·Vol. 17
·期 19
·4762
·
IF 3.1
Zhiyuan Song,Zainab Bibi,Sidra Chaudhary,Qinxiang Jia,Xiaoyong Li,Yang Sun
A water-soluble ternary copolymer bearing carboxyl, sulfonic, and amide functional groups was synthesized using ammonium persulfate-catalyzed free radical polymerization in water, resulting in high monomer conversion. This copolymer was then complexed with aluminum sulfate, forming an admixture containing Al(SO 4 )(OH)·5H 2 O, which was subsequently combined with silica gel. Characterization revealed that the synthesized copolymer formed a large, thin membrane that covered both the aluminum compounds and the silica gel blocks. The introduction of this complex admixture, combining the copolymer and aluminum sulfate, not only reduced the setting times of the cement paste but also enhanced the mechanical strengths of the mortar compared to using aluminum sulfate alone. The complex admixture led to the formation of katoite, metajennite, and C 3 A (tricalcium aluminate) in the mortar, demonstrating significant linking effects, whereas pure aluminum sulfate could not completely transform C 3 S within 24 h. Further addition of silica gel to the complex admixture further shortened the setting times of the paste, slightly reduced compressive strength, but improved flexural strength compared to the initial complex admixture. The silicon components appeared to fill the micropores and mesopores of the mortar, accelerating cement setting and enhancing flexural strength, while slightly decreasing compressive strength. This study contributed to the development of new cementing accelerators with improved hardening properties.
研究领域:
材料科学
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土木工程
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化学工程
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DOI
PubMed
高影响因子
MATERIALS AND STRUCTURES
·
2026
·Vol. 59
·期 6
·303
·
IF 3.9
Yin Jianhao,Liao Jiaxin,Kong Xiangming
The composition, moisture distribution, and microstructural evolutions of calcium-silicate-hydrate (C–S–H) in synthetic C–S–H (SynCSH) and hardened tricalcium silicate paste (HC 3 SP) during the first drying-resaturation (D-R) cycle were systematically compared using low-field 1 H-nuclear magnetic resonance (LF-NMR) and thermogravimetric analysis (TGA). The stoichiometric formulas of C–S–H in SynCSH and HC 3 SP were determined as C 0.9 SH 3.65 and C 2.0 SH 4.53 , respectively. Water contents of C–S–H quantified by TGA and LF-NMR exhibit good linear relationship. Three types of water, interlayer water, gel water and capillary water in C–S–H were identified by LF-NMR. Notable observations included the abnormal increase of interlayer water during the drying process and subsequent decrease during resaturation, along with irreversible decreases in capillary water and increases in gel water after D-R cycle, which were attributed to the rearrangement of C–S–H layered structures. SynCSH exhibited collapse of capillary pore structures following the D-R cycle, resulting in irreversible reductions in total water content. This finding confirms the validity of synthetic C–S–H as a model material for cementitious C–S–H research while highlighting its limitations in predicting the microstructural stability of real cement pastes under moisture cycling.
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高影响因子
Materials Today Chemistry
·
2025
·
IF 6.7
Meng Wu,Yucheng Zhou,Sichao Huang,Bixin Jiang,Peng Huang,Nan Liang,Laijun Xu
Preserving the vital pulp poses significant challenges in clinical pulp injury repair. Tricalcium silicate (C3S)-based cement has emerged as a successful pulp capping biomaterial. However, its efficacy in inducing pulp-dentin complex regeneration requires enhancement, and handling difficulties, poor anti-collapsible ability and inadequate self-setting performance remain significant obstacles, restricting its broader application in endodontics. In this study, a multifunctional SrCO 3 -doped C3S biocement (C3S-Sr/F127-nHA) reinforced by Pluronic® F127 thermoreversible hydrogel and nano hydroxyapatite (nHA) was developed to overcome the limitations of C3S-based cements. The thermoresponsive characteristic of F127 conferred the C3S pastes smart response behavior, allowing for optimal operability at room temperature and maintaining excellent anti-collapse properties at body temperature. C3S-Sr/F127-nHA exhibited an injectability rate of up to 93 %. nHA facilitated the hydration kinetics of C3S, resulting in reduced setting time and enhanced compressive strength. Furthermore, C3S-Sr/F127-nHA demonstrated excellent apatite mineralization ability, cytocompatibility, and potential for osteo/odontogenic induction. The inclusion of Sr 2+ ions and nHA promoted osteo/odontogenic differentiation of stem cells isolated from human exfoliated deciduous teeth (SHED). In vivo findings indicated that C3S-Sr/F127-nHA could stimulate the formation of a homogeneous dentin bridge. Consequently, C3S-Sr/F127-nHA is a promising biocement for use in regenerative endodontics.
研究领域:
牙科
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材料科学
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再生医学
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生物材料
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牙髓病学
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DOI
高影响因子
危险品化学品经营许可证（带存储）