Influence of temperature rising inhibitor on nucleation and growth process during cement hydration

2019 ◽  
Vol 681 ◽  
pp. 178403 ◽  
Author(s):  
Hao Zhang ◽  
Xin Liu ◽  
Pan Feng ◽  
Lei Li ◽  
Wenbing Wang
Keyword(s):  
Growth Process ◽  
Cement Hydration ◽  
Nucleation And Growth ◽  
Influence Of Temperature

Fundamental Research into Thin Films in a Developing Country

1972 ◽  
Vol 30 ◽  
pp. 500-501
Author(s):  
J.A. Eades ◽  
E. Grünbaum
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Empirical Process ◽  
Nucleation And Growth ◽  
Research Groups ◽  
Film Research ◽  
Fundamental Research ◽  
Controlled Deposition ◽  
The One ◽  
The University

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

scholarly journals The role of graphene/graphene oxide in cement hydration

2021 ◽  
Vol 10 (1) ◽  
pp. 768-778
Author(s):  
Shaoqiang Meng ◽  
Xiaowei Ouyang ◽  
Jiyang Fu ◽  
Yanfei Niu ◽  
Yuwei Ma
Keyword(s):  
Graphene Oxide ◽  
Cement Paste ◽  
Cement Hydration ◽  
Isothermal Calorimetry ◽  
High Mobility ◽  
Nucleation And Growth ◽  
Early Hydration ◽  
Mobility Of Ions ◽  
Cement Surface

Abstract Graphene (G) and graphene oxide (GO) have been shown to significantly improve the mechanical properties of cement-based materials. In this study, the effect of the G/GO on cement hydration was investigated. First, the zeta potential of G/GO in simulated solutions was tested, and the interaction between G/GO’s surface and Ca2+ was explored. Subsequently, scanning electron microscopy was used to observe the morphology of C–S–H nucleation and growth on the cement surface in the cement paste containing G/GO. Furthermore, XRD and TGA analyses were carried out on the hydration products of the sample. At last, isothermal calorimetry was applied to investigate the influence of G/GO on the early hydration of cement. The results showed that the addition of G/GO significantly accelerates C–S–H nucleation and growth on the cement surface. It is indicated that the high mobility ions derived by G/GO in the cement paste dominate the reason for the accelerated hydration of cement. The presence of G, especially GO, facilitates the mobility of ions, especially Ca2+, thus enhances the interaction between the cement surface and the ions. This strong interaction promotes the C–S–H nucleation and growth, and therefore, the hydration of the cement.

Nucleation and growth of Al2O3/metal composites by oxidation of aluminum alloys

1991 ◽  
Vol 6 (9) ◽  
pp. 1964-1981 ◽  
Author(s):  
O. Salas ◽  
H. Ni ◽  
V. Jayaram ◽  
K.C. Vlach ◽  
C.G. Levi ◽  
...  
Keyword(s):  
Growth Process ◽  
Nucleation And Growth ◽  
Al Alloy ◽  
Oxide Growth ◽  
Spinel Layer ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
Continuous Formation ◽  
Initial Event ◽  
Al Composite

The nucleation and growth mechanisms during high temperature oxidation of liquid Al−3% Mg and Al−3% Mg−3% Si alloys were studied with the aim of enhancing our understanding of a new composite fabrication process. The typical oxidation sequence consists of an initial event of rapid but brief oxidation, followed by an incubation period of limited oxide growth after which bulk Al2O3/Al composite forms. A duplex oxide layer, MgO (upper) and MgAl2O4 (lower), forms on the alloy surface during initial oxidation and incubation. The spinel layer remains next to the liquid alloy during bulk oxide growth and is the eventual repository for most of the magnesium in the original alloy. Metal microchannels developed during incubation continuously supply alloy through the composite to the reaction interface. During the growth process, a layered structure exists at the upper extremity of the composite, consisting of MgO at the top surface, MgAl2O4 (probably discontinuous), Al alloy, and finally the bulk Al2O3 composite containing microchannels of the alloy. The bulk oxide growth mechanism appears to involve continuous formation and dissolution of the Mg-rich oxides at the surface, diffusion of oxygen through the underlying liquid metal, and epitaxial growth of Al2O3 on the existing composite body. The roles of Mg and Si in the composite growth process are discussed.

Nucleation and growth process of atomic layer deposition platinum nanoparticles on strontium titanate nanocuboids

2017 ◽  
Vol 28 (18) ◽  
pp. 185704 ◽  
Author(s):  
Chuandao Wang ◽  
Linhua Hu ◽  
Kenneth Poeppelmeier ◽  
Peter C Stair ◽  
Laurence Marks
Keyword(s):  
Atomic Layer Deposition ◽  
Strontium Titanate ◽  
Platinum Nanoparticles ◽  
Growth Process ◽  
Atomic Layer ◽  
Nucleation And Growth ◽  
Layer Deposition

scholarly journals Influences and Mechanisms of Nano-C-S-H Gel Addition on Fresh Properties of the Cement-Based Materials with Sucrose as Retarder

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2345 ◽  
Author(s):  
Deyu Kong ◽  
Guangpeng He ◽  
Haiwen Pan ◽  
Yuehui Weng ◽  
Ning Du ◽  
...  
Keyword(s):  
Cement Paste ◽  
Cement Hydration ◽  
Diffusion Rate ◽  
Protective Layer ◽  
Xrd Analysis ◽  
Nucleation And Growth ◽  
Fresh Properties ◽  
Retarding Effect ◽  
3D Network ◽  
Cement Based Materials

Influences and mechanisms of chemically synthesized nano-C-S-H gel addition on fresh properties of the cement-based materials with sucrose as a retarder were investigated in this study. The results showed that the flow value of the fresh cement paste was gradually but slightly reduced with increasing nano-C-S-H gel addition due to its fibrous but well-dispersed characteristic in both water and cement paste. The semi-adiabatic calorimetry testing results verified that incorporation of nano-C-S-H gel could greatly mitigate the retarding effect of sucrose on cement hydration. The total organic carbon (TOC) indicated that the addition of the nano-C-S-H gel helps to reduce adsorption of the sucrose molecules into the protective layer, thus the semi-permeability of the protective layer was less reduced and that is why the addition of the nano-C-S-H gel can mitigate the retardation caused by the sucrose. Through XRD analysis, it was found that the CH crystals are more prone to grow along the (0001) plane with larger size in the paste with nano-C-S-H addition before the induction period starts, because the C-S-H nanoparticles can form 3D network to slow down the diffusion rate of the released ions and eliminate the convection in the paste, thus suppress the 3D nucleation and growth of the CH crystals. The XRD analysis also indicated a refinement of the ettringite crystals in the paste with sucrose addition, but introduction of nano-C-S-H gel did not show further refinement, which was also verified by the SEM observation.

Direct observation of a nucleation and growth process on an atomic scale

1987 ◽  
Vol 181 (1-2) ◽  
pp. 403-411 ◽  
Author(s):  
E. Ritter ◽  
R.J. Behm ◽  
G. Pötschke ◽  
J. Wintterlin
Keyword(s):  
Direct Observation ◽  
Growth Process ◽  
Nucleation And Growth ◽  
Atomic Scale

scholarly journals XRPD study of photo-induced HS→LS relaxation of hydrated [Fe(pyrazine)Pt(CN)4]

2014 ◽  
Vol 70 (a1) ◽  
pp. C772-C772
Author(s):  
Teresa Delgado ◽  
Antoine Tissot ◽  
Céline Besnard ◽  
Laure Guénée ◽  
Philip Pattison ◽  
...  
Keyword(s):  
Growth Process ◽  
Room Temperature ◽  
Spin Transition ◽  
Nucleation And Growth ◽  
Test Case ◽  
Relaxation Behaviour ◽  
Time Resolved ◽  
Layer Compound ◽  
Xrd Pattern ◽  
Large Hysteresis

The 2D layer compound [Fe(pyrazine)Pt(CN)4] has received a lot of attention because of its spin transition with a large hysteresis at room temperature, the possibility of bidirectional light-switching, and its potential as sensor for various gases [1], and in a recent study it served as test case for time-resolved electron diffraction on the nano-second time scale [2]. The present study focuses on the photo-induced HS → LS relaxation of the hydrated compound monitored by synchrotron XRPD measurements at 10 K (Figure 1). For the title compound, the time evolution of the XRD pattern shows a complex relaxation behaviour, which can be modelled with an initial random relaxation followed by a nucleation and growth process.

Nucleation, growth, and structure of Al–Mn quasicrystalline thin films prepared by high-temperature vapor deposition

1992 ◽  
Vol 7 (5) ◽  
pp. 1115-1125 ◽  
Author(s):  
P.B. Barna ◽  
A. Csanády ◽  
U. Timmer ◽  
K. Urban
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Growth Process ◽  
Depth Profiling ◽  
Nucleation And Growth ◽  
Quasicrystalline Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Mn Diffusion ◽  
High Temperature Vapor

The nucleation and growth of quasicrystalline thin films during sequential vapor deposition of aluminum and manganese on various substrates have been studied at temperatures between 530 and 650 K. The films were analyzed by transmission electron microscopy, electron diffraction, energy dispersive x-ray analysis, replica techniques, and Auger depth profiling. The quasicrystalline phase is identified as icosahedral. It nucleates on the surfaces of the Al films. There is no indication of substantial bulk Mn diffusion. The growth process is governed by diffusion of Al to the quasicrystal surface where it reacts with the incident Mn.

scholarly journals Nucleation and growth process of sodalite and cancrinite from kaolinite-rich clay under low-temperature hydrothermal conditions

2013 ◽  
Vol 16 (2) ◽  
pp. 424-438 ◽  
Author(s):  
Carlos Alberto Ríos Reyes ◽  
Craig Williams ◽  
Oscar Mauricio Castellanos Alarcón
Keyword(s):  
Low Temperature ◽  
Growth Process ◽  
Nucleation And Growth ◽  
Hydrothermal Conditions
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