scholarly journals Modifying Cement Hydration with NS@PCE Core-Shell Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Yue Gu ◽  
Qianping Ran ◽  
Wei She ◽  
Jiaping Liu
Keyword(s):  
Cement Hydration ◽  
Fine Particles ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Pozzolanic Reactivity ◽  
Characteristic Values ◽  
Core Shell Nanoparticles ◽  
The Impact

It is generally accepted that fine particles could accelerate cement hydration process, or, more specifically, this accelerating effect can be attributed to additional surface area introduced by fine particles. In addition to this view, the surface state of fine particles is also an important factor, especially for nanoparticles. In the previous study, a series of nano-SiO2-polycarboxylate superplasticizer core-shell nanoparticles (NS@PCE) were synthesized, which have a similar particle size distribution but different surface properties. In this study, the impact of NS@PCE on cement hydration was investigated by heat flow calorimetry, mechanical property measurement, XRD, and SEM. Results show that, among a series of NS@PCE, NS@PCE-2 with a moderate shell-core ratio appeared to be more effective in accelerating cement hydration. As dosage increases, the efficiency of NS@PCE-2 would reach a plateau which is quantified by various characteristic values. Compressive strength results indicate that strength has a linear correlation with cumulative heat release. A hypothesis was proposed to explain the modification effect of NS@PCE, which highlights a balance between initial dispersion and pozzolanic reactivity. This paper provides a new understanding for the surface modification of supplementary cementitious materials and their application and also sheds a new light on nano-SiO2 for optimizing cement-based materials.

Synthesis of SiO2-PCE Core-Shell Nanoparticles and its Modification Effects on Cement Hydration

2016 ◽  
Vol 711 ◽  
pp. 249-255 ◽  
Author(s):  
Yue Gu ◽  
Qian Ping Ran ◽  
Xin Shu ◽  
Cheng Yu ◽  
Hong Lei Chang ◽  
...  
Keyword(s):  
Cement Hydration ◽  
Cementitious Materials ◽  
Aqueous System ◽  
Core Shell ◽  
High Concentration ◽  
Shell Nanoparticles ◽  
Polycarboxylate Superplasticizer ◽  
Effective Dispersion ◽  
Concentration Of Ions ◽  
Core Shell Nanoparticles

NanoSiO2 was widely used to modify the property of cementitious materials, however, for nanoparticles used in cement-based materials, key problem is the effective dispersion. The surface modification technology can be introduced to promote dispersion of nanoparticles in aqueous system, especially in cement pore solution, which possess high concentration of ions. In this study, at first, NanoSiO2-polycarboxylate superplasticizer (SiO2-PCE) core-shell nanoparticle was synthesized from silanized polycarboxylate superplasticizer and colloidal nanoSiO2 by the “grafting to” method, then SiO2-PCE was testified by UV-Vis, FTIR, and TGA. Additionally, stability of SiO2-PCE and its effect on cement hydration were investigated. Results shows: SiO2-PCE possess higher stability in saturated calcium hydroxide solution compared to nanoSiO2, and heat development of cement hydration can be regulated by shell structure of SiO2-PCE. The research implied a new approach for nanoSiO2 to optimize cement-based composites.

Synthesis of nanoSiO2@PCE core-shell nanoparticles and its effect on cement hydration at early age

2016 ◽  
Vol 114 ◽  
pp. 673-680 ◽  
Author(s):  
Yue Gu ◽  
Qianping Ran ◽  
Xin Shu ◽  
Cheng Yu ◽  
Honglei Chang ◽  
...  
Keyword(s):  
Cement Hydration ◽  
Core Shell ◽  
Early Age ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Preparation of TiO2-g-Polystyrene Nanosphere and its Application in Toughening PS Matrix

2010 ◽  
Vol 97-101 ◽  
pp. 1677-1680 ◽  
Author(s):  
Xiao Ming Sang ◽  
Peng Wu ◽  
Gui Xiang Hou ◽  
Shou Wu Yu
Keyword(s):  
Impact Strength ◽  
Core Shell ◽  
Gravimetric Analysis ◽  
Nano Tio2 ◽  
Shell Nanoparticles ◽  
Maximum Value ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Core Shell Nanoparticles ◽  
The Impact

TiO2-g-Polystyrene(PS) nano-microspheres were prepared by grafted styrene monomer on the surface of nano-TiO2 particles via emulsion polymerization, and its surface and morphology were studied by Transmission electron microscopes(TEM), Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analysis(TGA). The results showed that the TiO2-g-PS nano-microsphere had a structure of sphericity composed of TiO2 and PS as core and shell respectively. The core-shell nanoparticles were subsequently used as filler in a PS matrix, and the impact strength of the TiO2-g-PS/PS composites were studied. The results showed that the impact strength of the composite material could be improved obviously, the maximum value of impacted strength of the TiO2-g-PS/PS was 1.75kJ/m2, which was 180% higher than that of pure PS. Drawing from the results, it could be confirmed that these core-shell TiO2-g-PS nanosphere fillers could toughen the PS matrix.

scholarly journals Designer Core–Shell Nanoparticles as Polymer Foam Cell Nucleating Agents: The Impact of Molecularly Engineered Interfaces

2021 ◽  
Vol 13 (14) ◽  
pp. 17034-17045
Author(s):  
Shanqiu Liu ◽  
Sissi de Beer ◽  
Kevin M. Batenburg ◽  
Hubert Gojzewski ◽  
Joost Duvigneau ◽  
...  
Keyword(s):  
Foam Cell ◽  
Core Shell ◽  
Nucleating Agents ◽  
Polymer Foam ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
The Impact

scholarly journals Iron Oxide–Silica Core–Shell Nanoparticles Functionalized with Essential Oils for Antimicrobial Therapies

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1138
Author(s):  
Cristina Chircov ◽  
Maria-Florentina Matei ◽  
Ionela Andreea Neacșu ◽  
Bogdan Stefan Vasile ◽  
Ovidiu-Cristian Oprea ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Essential Oils ◽  
Synthesis Method ◽  
Gas Chromatography Mass Spectrometry ◽  
In Vitro Tests ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Nanostructured Systems ◽  
Core Shell Nanoparticles ◽  
The Impact

Recent years have witnessed a tremendous interest in the use of essential oils in biomedical applications due to their intrinsic antimicrobial, antioxidant, and anticancer properties. However, their low aqueous solubility and high volatility compromise their maximum potential, thus requiring the development of efficient supports for their delivery. Hence, this manuscript focuses on developing nanostructured systems based on Fe3O4@SiO2 core–shell nanoparticles and three different types of essential oils, i.e., thyme, rosemary, and basil, to overcome these limitations. Specifically, this work represents a comparative study between co-precipitation and microwave-assisted hydrothermal methods for the synthesis of Fe3O4@SiO2 core–shell nanoparticles. All magnetic samples were characterized by X-ray diffraction (XRD), gas chromatography-mass spectrometry (GC-MS), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetry and differential scanning calorimetry (TG-DSC), and vibrating sample magnetometry (VSM) to study the impact of the synthesis method on the nanoparticle formation and properties, in terms of crystallinity, purity, size, morphology, stability, and magnetization. Moreover, the antimicrobial properties of the synthesized nanocomposites were assessed through in vitro tests on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. In this manner, this study demonstrated the efficiency of the core–shell nanostructured systems as potential applications in antimicrobial therapies.

Performance of cement mortar with waste ground clay brick

MRS Advances ◽  
2018 ◽  
Vol 3 (34-35) ◽  
pp. 2041-2050
Author(s):  
Mohammed Si-Ahmed ◽  
Said Kenai ◽  
Elhem Ghorbel
Keyword(s):  
Cement Hydration ◽  
Thermo Gravimetric Analysis ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Partial Substitution ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Cement Production ◽  
The Impact

ABSTRACTAn effective way to reduce the impact of cement production on the environment is to use supplementary cementitious materials (SCM) as a partial substitution to cement. In addition to the reduction in cost and energy saving, the use of SCM in cement for the manufacture of mortar and concrete offers technical advantages. In this paper, cement was partially substituted by fines obtained from crushed recycled bricks recovered from a brick plant. The level of substitution was either 0%, 5%, 10% or 15% by weight of cement. The results show that cement substitution by brick fines resulted in a slight loss of workability with the increase of the substitution rate. Substitutions rates of 5% and 10% produced at long-term comparable strength as control mortars. The differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) results show cement hydration improved significantly with different rates of substitutions at 28 and 180 days of age.

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