Effect of Preparation Parameters on the Structure and Property of Montmorillonite/Alkylammonium Complexes

2010 ◽  
Vol 158 ◽  
pp. 97-105
Author(s):  
Xian Jun Lu ◽  
Jun Qiu ◽  
Yu Qin Liu ◽  
Ping Chen
Keyword(s):  
Retention Time ◽  
Layer Structure ◽  
Structure And Property ◽  
Intercalation Reaction ◽  
Maximum Value ◽  
Interlayer Structure ◽  
Adsorption Amount

A series of montmorillonite/alkylammonium complexes were prepared by the intercalation reaction between montmorillonite and Octadecyltrimethylammonium chloride (OTA). The effects of OTA dosage and intercalation duration on the structure and gelating properties of the complexes were investigated. And, the correlation between the structure of complexes and their gel viscosities were discussed. Results indicate that the OTA dosage and retention time have remarkable influence on the structure and gelating properties of montmorillonite/alkylammonium complexes, and the gelating properties also relates to the arrangement of the alkylammonium molecules in the interlayers of montmorillonite. Along with the increase of the OTA dosage under the same retentation time, both the d001 value of the montmorillonite/alkylammonium complexes and the adsorption amount of OTA increase to some extent, and the layer structure of the complex tends to show an interstratification structure. However, maximum gel viscosity of the complex was obtained at a moderate OTA dosage of 1.1~1.3CEC. Along with the increase of the retentation time, the adsorption amount of the OTA shows little variations, but the interlayer structure of the complex prepared under longer retention time tends to form a stable monolayer structure from an unstable interstratification structure under shorter retention time, and the gel viscosity of the complex increases gradually to the maximum value.

Principle and structure of a multi-chamber piezoelectric pump with large flow rate integrated into printed circuit board

2022 ◽  
pp. 1045389X2110721
Author(s):  
Yun-Hao Peng ◽  
Dai-Hua Wang ◽  
Lian-Kai Tang
Keyword(s):  
Flow Rate ◽  
Compression Ratio ◽  
Layer Structure ◽  
Experimental Results ◽  
Processing Technology ◽  
Rate Model ◽  
Piezoelectric Pump ◽  
Central Deflection ◽  
Maximum Value ◽  
Large Flow

Parametric simulation of multi-chamber piezoelectric pump proposed by authors shows that its flow rate is positively correlated with chamber compression ratio when height of chamber wall is not less than central deflection of circular piezoelectric unimorph actuator (CPUA). Therefore, in this paper, principle and structure of multi-chamber piezoelectric pump with novel CPUAs with three-layer structure are proposed and realized, so as to improve its chamber compression ratio, and then improve its flow rate. Its processing technology compatible with PCB processing technology is studied and its flow rate model is established. Central deflection of CPUA with three-layer structure and the flow rate characteristics are tested. Experimental results show that when the central deflection of CPUA with three-layer structure reaches the maximum value of 106.8 μm, the chamber compression ratio and flow rate of multi-chamber piezoelectric pump reach the maximum value of 50% and 3.11 mL/min, respectively. The maximum flow rate is increased by 622% compared to unimproved pump. By comparing experimental results with numerical and finite element simulation results, the realized multi-chamber piezoelectric pump has large flow rate and the established flow rate model can predict its flow rate.

scholarly journals Raman Spectra Shift of Few-Layer IV-VI 2D Materials

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Minwoo Park ◽  
Jin Sik Choi ◽  
Li Yang ◽  
Hoonkyung Lee
Keyword(s):  
Raman Spectroscopy ◽  
Layer Structure ◽  
2D Materials ◽  
Vibrational Modes ◽  
Metal Atoms ◽  
Raman Modes ◽  
Interlayer Structure ◽  
Optical Applications ◽  
Few Layer Graphene ◽  
Bulk Structures

AbstractRaman spectroscopy is the most commonly used method to investigate structures of materials. Recently, few-layered IV-VI 2D materials (SnS, SnSe, GeS, and GeSe) have been found and ignited significant interest in electronic and optical applications. However, unlike few-layer graphene, in which its interlayer structures such as the number of its layers are confirmed through measurement of the Raman scattering, few-layer IV-VI 2D materials have not yet been developed to the point of understanding their interlayer structure. Here we performed first-principles calculations on Raman spectroscopy for few-layer IV-VI 2D materials. In addition to achieving consistent results with measurements of bulk structures, we revealed significant red and blue shifts of characteristic Raman modes up to 100 cm−1 associated with the layer number. These shifts of lattice vibrational modes originate from the change of the bond lengths between the metal atoms and chalcogen atoms through the change of the interlayer interactions. Particularly, our study shows weak covalent bonding between interlayers, making the evolution of Raman signals according to the thickness different from other vdW materials. Our results suggest a new way for obtaining information of layer structure of few-layer IV-VI 2D materials through Raman spectroscopy.

Interlayer structure of organically modified montmorillonites: Effect of surfactant loading

2005 ◽  
Vol 20 (2) ◽  
pp. 357-363 ◽  
Author(s):  
Qiang Zheng ◽  
Bo Xu ◽  
Yihu Song ◽  
Hongmei Yang ◽  
Yi Pan
Keyword(s):  
Ion Exchange ◽  
Conformational Disorder ◽  
Intercalation Reaction ◽  
Organically Modified ◽  
Interlayer Structure ◽  
Precipitate Layer

The surfactant cetyltrimethylammonium ion (CTA+) was confined within the galleries of montmorillonite (MMT) to obtain a series of organo-montmorillonites (C16-MMTs) through an ion-exchange intercalation reaction. The C16-MMT formed a single precipitate layer when CTA+ loading was 18.3 wt% but stratified at high loadings. The conformational disorder increased with increasing CTA+ loading. The upper precipitate was characterized by a larger gallery height and a higher surfactant loading in comparison with lower precipitate. The confined methylene chains adopted a lateral monolayer with a small percentage of conformation freedoms at CTA+ loading of 18.3 wt%. The intercalated methylene chains were arranged either in a lateral monolayer or in a tilted interdigitated bilayer at CTA+ loading of 24.7 wt% while in either a tilted interdigitated bilayer or a lateral bilayer at high CTA+ loadings. The different arrangements of methylene chains intercalated in the MMT galleries are believed to be the reason for the stratification.

Structure and Property Coating Modification by High Energy Density

2014 ◽  
Vol 1013 ◽  
pp. 153-157 ◽  
Author(s):  
Viktor A. Vlasov ◽  
Yurii F. Ivanov ◽  
Gennady Volokitin ◽  
Anton D. Teresov ◽  
Anatolii A. Klopotov
Keyword(s):  
Electron Beam ◽  
Layer Structure ◽  
Pure Titanium ◽  
High Energy ◽  
Substrate Material ◽  
High Energy Density ◽  
Commercially Pure Titanium ◽  
Structure And Property ◽  
Multi Phase ◽  
Arc Plasma Torch

The paper reviews the results of investigations of the surface layer structure and properties of type 35-L steel and commercially pure titanium modified by plasma flows (arc plasma torch with the powder blown into an arc), electro-explosive alloying of titanium specimens, and high energy electron-beam treatment performed on the vacuum electron-beam plant SOLO. It is shown that the surface treatments under review have lead to a multilayer and multi-phase structure formed by crystalline particles of sub-microsized and nanosized range, mechanical (microhardness) and tribological (wear resistance) properties of which exceed manifold that of the substrate material.

Controlling DOPA adsorption via interacting with polyelectrolytes: layer structure and corrosion resistance

Soft Matter ◽  
2020 ◽  
Vol 16 (21) ◽  
pp. 4912-4918
Author(s):  
Ting Chen ◽  
Hui Yang ◽  
Ming Yang ◽  
Fanghui Liu ◽  
Jiazhong Wu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Composite Materials ◽  
Protein Adsorption ◽  
Molecular Conformation ◽  
Layer Structure ◽  
Structure And Property ◽  
P Protein ◽  
Anticorrosion Performance

Protein adsorption on polyelectrolyte (PE) surfaces can be tuned by PE layer structure and property, which plays an important role in understanding the correlation between molecular conformation and anticorrosion performance of composite materials.

scholarly journals Study of Phase Transition in Bi3TiNbO9-BaBi2Nb2O9 Ceramics

2016 ◽  
Vol 61 (3) ◽  
pp. 1503-1510 ◽  
Author(s):  
M. Adamczyk ◽  
J. Kusz ◽  
W. Hofmeister ◽  
M. Zubko ◽  
L. Kozielski ◽  
...  
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Dielectric Permittivity ◽  
Layer Structure ◽  
Lead Free ◽  
Maximum Value ◽  
Average Grain Size ◽  
Wide Range ◽  
The Subject ◽  
And Shifts

Abstract The subject of the paper is lead free bismuth layer structure oxides (1-x)Bi3TiNbO9-xBaBi2Nb2O9 (x=0; 1; 2; 3 mol). The influence of Bi3TiNbO9/BaBi2Nb2O9 ratio on dielectric and structural properties was studied in a wide range of temperatures. Change in the ratio causes a decrease in the maximum value of dielectric permittivity and shifts the temperature of ε’max to low values, leading to linear decreasing of average grain size and linear increasing of ceramics density. These results indicate an augment of the packing degree and the participation of pores are significantly decreased with the increase of BaBi2Nb2O9 compound intake. Moreover, for 0.7Bi3TiNbO9-0.3BaBi2Nb2O9 ceramics the dielectric phase transition is broadened and the properties characteristic for the ferroelectric relaxor appear.

scholarly journals Layer-Edge Patterns Exploration and Presentation in Multiplex Networks: From Detail to Overview via Selections and Aggregations

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 387 ◽  
Author(s):  
Xitao Zhang ◽  
Lingda Wu ◽  
Shaobo Yu ◽  
Kang Li
Keyword(s):  
Real World ◽  
Topological Structure ◽  
Visual Analysis ◽  
Layer Structure ◽  
Real World Data ◽  
Multiplex Networks ◽  
Level Information ◽  
Interlayer Structure ◽  
High Level ◽  
Multiple Interactions

Multiplex networks have been widely used to describe the multi-type connections of entities in the real world. However, researches for multiplex networks visualization unilaterally focus on the presentation of topological structure, lacking of specific high-level information presentation for quantitative comparison of interlayer structure. Users cannot participate in the exploration and freely choose the layers (or sub-graphs, regions, etc.) of interest for structural comparison. Contraposing the layer-edge patterns visual analysis tasks of multiplex networks, this paper puts forward a novel solution for exploration and analysis that tightly couples topological structure and high-level patterns. It mainly contains a multi-force directed model to realize the balanced layout of nodes in multi-layer topology, as well as two kinds of high-level patterns of which the visual representations are, respectively, designed by a familiar metaphor—that is, the similar pattern representation based on the area-proportional Venn diagrams and the interaction pattern representation based on the directed arrows. Furthermore, views association is implemented through underlying data sharing and multiple interactions which can be used to gain insights through the creation of selections of interest and produce high-level infographic-style overviews simultaneously. The experiments on real-world data demonstrate the support of the proposed method for layer-edge patterns analysis tasks in multiplex networks and the effectiveness for analyzing the multi-layer structure of multiplex networks.

scholarly journals Preparation and Antiflame Performance of Expandable Graphite Modified with Sodium Hexametaphosphate

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Hongmei Zhao ◽  
Xiuyan Pang ◽  
Zhixiao Zhai
Keyword(s):  
Layer Structure ◽  
Sodium Hexametaphosphate ◽  
Expandable Graphite ◽  
Mass Ratio ◽  
Linear Low Density Polyethylene ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
Intercalation Reaction ◽  
Graphite Oxidation ◽  
Expansion Temperature

A kind of polyphosphate modified expandable graphite (EGp) was prepared in graphite oxidation and intercalation reaction with KMnO4 as oxidant, H2SO4 as intercalator, and sodium hexametaphosphate (SHMP) as assistant intercalator. The feasible mass ratio of C : KMnO4 : H2SO4 (98%) : SHMP was determined as 1.0 : 0.3 : 4.5 : 0.6, H2SO4 was diluted to 77 wt% before intercalation reaction, and the reaction lasted for 40 min at 40°C. Expanded volume and initial expansion temperature of the prepared EGp reached 600 mL/g (at 800°C) and 151°C, respectively. X-ray diffraction spectroscopy testified the intercalation and layer structure of EGp, and Fourier transform infrared spectroscopy illuminated the intercalated functional groups. Flame retardance of the prepared EGp and the referenced EG (with only H2SO4 as intercalator) for linear low density polyethylene (LLDPE) was also investigated. Addition of 30 wt% EGp to the polymer improved the limiting oxygen index (LOI) from 17.5 to 27.3%. On the other hand, the LOI of the same amount of the referenced EG was only 24.6%. Assistant intercalation of SHMP improved the dilatability and flame retardancy.

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