Fabrication of poly(β-cyclodextrin-co-citric acid)/bentonite clay nanocomposite hydrogel: thermal and absorption properties

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 82438-82449 ◽  
Author(s):  
Abolfazl Heydari ◽  
Hassan Sheibani
Keyword(s):  
Citric Acid ◽  
Bentonite Clay ◽  
Nanocomposite Hydrogel ◽  
Absorption Properties ◽  
Melt Intercalation ◽  
Intercalative Polymerization

A β-cyclodextrin (β-CD)/bentonite clay (BNC) nanocomposite hydrogel was prepared through combining in situ intercalative polymerization and melt intercalation methods.

scholarly journals Structure and swelling of polymer-clay composites

2016 ◽  
Vol 11 (3) ◽  
pp. 213 ◽  
Author(s):  
R.S. Iminova ◽  
Sh.N. Zhumagalieva ◽  
M.K. Beisebekov ◽  
Zh.A. Abilov ◽  
G.A. Mun
Keyword(s):  
Morphological Structure ◽  
Bentonite Clay ◽  
Physiological Solution ◽  
Cross Linking ◽  
Swelling Degree ◽  
Degree Of Swelling ◽  
East Kazakhstan ◽  
Complex Polymer ◽  
Intercalative Polymerization

<p>Composition gels on the basis of bentonite clay of Manrak deposit (East-Kazakhstan region) and nonionogenic polymers - poly-2-hydroxyethyl-acrylate and polyacrylamide were synthesized by radical intercalative polymerization in situ with various content o f cross-linking agent N,N-methylene-bisacrylamide and with time of intercalation about 8 hours. The morphological structure, the nature of interaction of components and the swelling ability of composition gels were studied by scanner electron microscopy, equilibrium swelling and IR- spectroscopy methods. By studying of morphological structure it was determined, that the polymer-clay composition gels, synthesized by intercalative polymerization, are most homogenous and interconsistency in case of “acrylamide-clay” composition in contrast with “2-hydroxyethylacrylate-clay” composition. For “acrylamide-clay” gels the swelling degree of gels was stated to decrease with the increase in the content of cross-linking agent and ionic strength, but “2-hydroxyethylacrylate -clay” compositions have the extremely character of swelling, where maximum degree of swelling account for gel with content of cross-linking agent 1*10<sup>-2</sup>М. Interaction of composition components was realized on account of hydrogen bonds with formation of chemically cross-linked complex polymer-clay. Decrease of swelling degree of compositions in physiological solution points to acquisition of polyelectrolyte nature of composition gels on account of combination of nonionogenic macromolecules of polymers with negatively charged particles of bentonite clay. For intercalated samples of polymer-clay compositions, the degree of swelling at all degrees of cross-linking is between those for pure polymers and pure clay, that in turn, agrees with the conclusion on the great composition homogeneity of samples with preliminary intercalation. As of results of holding investigation fit is safe to say, that obtained polymer-clay composition gels are potential sorbents and prolongated carriers of medicine</p>

scholarly journals Simultaneously controlling heat conduction and infrared absorption with a textured dielectric film to enhance the performance of thermopiles

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yunqian He ◽  
Yuelin Wang ◽  
Tie Li
Keyword(s):  
Heat Conduction ◽  
Infrared Absorption ◽  
High Performance ◽  
Performance Enhancement ◽  
Dielectric Film ◽  
Great Influence ◽  
Thermal Conductance ◽  
Molding Process ◽  
Absorption Properties

AbstractThe heat conduction and infrared absorption properties of the dielectric film have a great influence on the thermopile performance. Thinning the dielectric film, reducing its contact area with the silicon substrate, or adding high-absorptivity nanomaterials has been proven to be effective in improving thermopiles. However, these methods may result in a decrease in the structural mechanical strength and increases in the fabrication complexity and cost. In this work, a new performance-enhancement strategy for thermopiles by simultaneously controlling the heat conduction and infrared absorption with a TExtured DIelectric (TEDI) film is developed and presented. The TEDI film is formed in situ by a simple hard-molding process that is compatible with the fabrication of traditional thermopiles. Compared to the control FLat DIelectric (FLDI) film, the intrinsic thermal conductance of the TEDI film can be reduced by ~18–30%, while the infrared absorption can be increased by ~7–13%. Correspondingly, the responsivity and detectivity of the fabricated TEDI film-based thermopile can be significantly enhanced by ~38–64%. An optimized TEDI film-based thermopile has achieved a responsivity of 156.89 V·W−1 and a detectivity of 2.16 × 108 cm·Hz1/2·W−1, while the response time constant can remain <12 ms. These results exhibit the great potential of using this strategy to develop high-performance thermopiles and enhance other sensors with heat transfer and/or infrared absorption mechanisms.

Ti3C2MXenes modified with in situ grown carbon nanotubes for enhanced electromagnetic wave absorption properties

2017 ◽  
Vol 5 (16) ◽  
pp. 4068-4074 ◽  
Author(s):  
Xinliang Li ◽  
Xiaowei Yin ◽  
Meikang Han ◽  
Changqing Song ◽  
Hailong Xu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Wave ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Catalytic Chemical Vapor Deposition ◽  
Wave Absorption

Ti3C2TxMXenes modified within situgrown carbon nanotubes (CNTs) are fabricatedviaa simple catalytic chemical vapor deposition (CVD) process.

Relation Between CO2 Evolution and in situ Reduction of Nitrate in Wheat Leaves

1981 ◽  
Vol 8 (6) ◽  
pp. 515 ◽  
Author(s):  
MS Naik ◽  
DJD Nicholas
Keyword(s):  
Citric Acid ◽  
Nitrate Reduction ◽  
Citric Acid Cycle ◽  
Nitrate Assimilation ◽  
Co2 Evolution ◽  
In Situ Reduction ◽  
Acid Cycle ◽  
Nitrite Production ◽  
Wheat Leaves

In wheat leaf discs the evolution of 14CO2 from exogenously supplied 14C-labelled citric acid cycle intermediates was stimulated during the in situ anaerobic reduction of nitrate in the dark. Under these conditions, however, [1,4-14C]succinate was not metabolized. Similarly, when leaves were allowed to assimilate 14CO2 in the dark, thus producing endogenously labelled organic acids, the subsequent evolution of 14CO2 from discs prepared from these leaves was strongly dependent on nitrate reduction. A 1 : 1 stoichiometry between nitrite production and CO2 evolution was recorded during this in situ reduction of nitrate. The in situ reduction of nitrate was inhibited by malonate and D-malate and this effect was reversed by fumarate, probably by generating L-malate within the mitochondria. Mitochondrial NAD-malic enzyme (decarboxylating) (EC 1.1.1.38) was similarly inhibited competitively by malonate and D-malate, but not by succinate. These results indicate that the citric acid cycle dehydrogenases which generate CO2 supply NADH for nitrate reduction in wheat leaves. It is likely that, under anaerobic conditions, nitrate acts as an alternative oxidant to O2 for the NADH generated by the citric acid cycle dehydrogenases resulting in simultaneous evolution of CO2. This ensures that the citric acid cycle operates at the required rate for nitrate assimilation.

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