Synthesis of small Fe2O3 nanocubes and their enhanced water vapour adsorption–desorption properties

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 84587-84591 ◽  
Author(s):  
Feng Cao ◽  
Duanyang Li ◽  
Ruiping Deng ◽  
Lijian Huang ◽  
Daocheng Pan ◽  
...  

Uniform ordered Fe2O3 nanocubes showed an excellent humidity-controlling ability, due to their appropriate pore size distribution near the condensation critical radius.

2016 ◽  
Vol 30 (3) ◽  
pp. 375-381 ◽  
Author(s):  
Alicja Szatanik-Kloc

Abstract The plant reactions on Al-stress include i.a. change of the surface area of the roots, which in the physicochemistry of plants characterizes the transport of water and ions through the root. The object of this study is the specific surface area of the roots of plants which are tolerant to aluminium, such as rye. Plants of rye were grown in a nutrient solution for 14 days at pH 4.5 in the presence of Al3+ ions of concentration 10, 20, and 40 mg dm−3. The control plants were grown continuously at pH 7 or pH 4.5 without Al3+. The apparent surface area and adsorption energy of the plants roots were determined from water vapour adsorption – desorption data. The apparent surface area of roots growing in the aluminium was (with respect to control) statistically significantly lower. There were no statistically significant differences in the apparent surface area of the roots which grew in pH 7, pH 4.5 without Al3+. The average water vapour adsorption energy of the root surface, under stress conditions decreased. In the roots grown in the presence of Al+3, there was a slight decrease in high energy adsorption centres and an increase in the amount of low-energy centres.


Clay Minerals ◽  
2002 ◽  
Vol 37 (3) ◽  
pp. 451-456 ◽  
Author(s):  
F. Ohashi ◽  
S.-I . Wada ◽  
M. Suzuki ◽  
M. Maeda ◽  
S. Tomura

AbstractThe amorphous aluminosilicate allophane was synthesized by rapid mixing of inorganic solutions with high initial concentrations (10 – 100 mmol/l) followed by hydrothermal treatment. X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed homogeneous products having a hollow spherical amorphous structure with a particle diameter of 3 – 5 nm. The amorphous products had a high BET specific surface area (490 – 552 m2/g) in comparison with natural allophane and had a narrow pore-size distribution (2 – 5 nm in diameter). The results of water vapour adsorption isotherm studies showed a gradual increase over the range of relative water vapour pressure of 0.6 – 0.9 and reached a maximum of ∼85 wt.%. The synthetic allophane shows promise as an adsorbent material because of its high adsorption-desorption capacity and its unique structure.


2015 ◽  
Vol 1126 ◽  
pp. 87-92
Author(s):  
Olga Koronthalyova

An effect of the presence of sodium chloride on water vapour adsorption/desorption loop was quantified for two types of commonly used ceramic bricks with different hygroscopic ability. The measurements were carried out for salt free materials and saline materials contaminated with sodium chloride solutions of two different concentrations. It was found out that at relative humidity higher than deliquescence point, the hysteretic effects of the saline bricks were similar or less significant as the ones of the salt free bricks. In this range of relative humidity the desorption moisture contents did not exceed the values predicted using the simply additive model. However, for the relative humidity lower than deliquescence point the hysteretic effects of the saline bricks were more significant than the ones of the salt free bricks. The effect was of importance in the case of hygroscopic ceramic brick where obtained desorption moisture contents of the saline bricks were noticeably higher than for the salt free brick.


2016 ◽  
Vol 315 ◽  
pp. 42-51 ◽  
Author(s):  
Masoud Jahandar Lashaki ◽  
John D. Atkinson ◽  
Zaher Hashisho ◽  
John H. Phillips ◽  
James E. Anderson ◽  
...  

1995 ◽  
Vol 12 (3) ◽  
pp. 203-209 ◽  
Author(s):  
R.N. Nickolov ◽  
D.R. Mehandjiev

Water vapour adsorption on activated carbon has been investigated by an analysis of the nitrogen isotherms determined on carbon samples after their initial wetting at the same relative pressure followed by freezing. The simplified equation for micropore size distribution has been used. A relatively narrow range of pre-adsorbed water values has been found, within which the microporous space of the initial activated carbon changes as a result not only of filling but also of elimination (blocking) of parts of the texture.


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