scholarly journals Anomalous effect of Cu2O and CuO deposit on the porosity of a macroreticular anion exchanger

2021 ◽  
Vol 23 (6) ◽  
Author(s):  
Elżbieta Kociołek-Balawejder ◽  
Ewa Stanisławska ◽  
Irena Jacukowicz-Sobala ◽  
Marek Jasiorski
Keyword(s):  
Anion Exchanger ◽  
Mercury Intrusion Porosimetry ◽  
Copper Oxides ◽  
Anomalous Effect ◽  
Copper Compounds ◽  
Freeze Dried ◽  
Contraction Effect ◽  
Adsorption Desorption ◽  
Desorption Method ◽  
Pure Resin

AbstractWhen synthesizing copper compounds containing polymeric adsorbents, it was found that the two copper oxides, Cu2O and CuO, deposited in the skeleton of a strongly basic macroreticular anion exchanger (An) radically diminished the porosity of the obtained composites in relation to the host material. In order to investigate this phenomenon more closely, An/Cu2O and An/CuO (both based on the commercial anion exchanger Amberlite IRA900Cl), containing 8.6 and 8.2 wt% Cu, respectively, were subjected to scrutiny. The porous characteristics of the thermally dried and freeze-dried samples were determined using the N2 adsorption–desorption method and mercury intrusion porosimetry. The thermally dried samples lost their porosity and increased their bulk density in relation to the pure resin indicated a significant reduction in their volume. It was found that during drying, the grains shrank as much as the pores collapsed. The decay of the porous structure resulted from the surface morphology of the Cu2O and CuO particles and their tendency to agglomerate. Both freeze-dried samples retained the porous characteristics typical for macroporous anion exchangers. In contrast to the most popular hybrid ion exchangers containing hydrated polyvalent metal oxides (such FeOOH), An/Cu2O and An/CuO showed markedly strong volume contraction effect in relation to moisture content. Graphical abstract

Preparation, Characterization and Photocatalytic Activity of F, Fe-Codoped Nano-TiO2

2013 ◽  
Vol 448-453 ◽  
pp. 169-173
Author(s):  
Chun Yan Yan ◽  
Wen Tao Yi
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Hydrothermal Process ◽  
Neutral Red ◽  
Reaction Model ◽  
X Ray Diffraction ◽  
Pseudo First Order Reaction ◽  
Adsorption Desorption ◽  
Desorption Method

Pure and F, Fe-codoped TiO2 were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO3)2·6H2O and NH4F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO2. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO2 had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

Modeling of the Adsorption/Desorption Characteristics and Properties of Anthocyanins from Extruded Red Cabbage Juice by Macroporous Adsorbent Resin

2019 ◽  
Vol 15 (1-2) ◽  
Author(s):  
Pingjing Zhang ◽  
Liping Wang ◽  
Sheng Fang
Keyword(s):  
Adsorption Process ◽  
Fixed Bed ◽  
Order Kinetic ◽  
Adsorption And Desorption ◽  
Red Cabbage ◽  
Macroporous Resins ◽  
Freeze Dried ◽  
Order Kinetic Model ◽  
Color Density ◽  
Adsorption Desorption

AbstractThe adsorption/desorption characteristics, modeling and properties of anthocyanins from extruded red cabbage juice by macroporous resins were investigated. The static adsorption and desorption capacities of red cabbage anthocyanins on five macroporous resins were measured and compared. The X-5 resin showed the best capacities and was selected for the adsorption kinetics, isotherms and elution studies. The pseudo-second-order kinetic model and Langmuir isotherm model were used to describe the adsorption process and mechanism. Dynamic adsorption and desorption tests were performed on a fixed-bed column, and the loading and eluent conditions were optimized. The purity of anthocyanins in freeze-dried purified powder by the resin adsorption process is 21.3 ± 0.9 wt % and shows better stability in the air than the unpurified one. Finally, the antioxidant activity and color properties including color density, color intensity, color tonality and degradation index of the purified powders were measured.

Binding of cadmium by montmorillonite humic acid mixtures - Miscible displacement experiments

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 391 ◽  
Author(s):  
GD Campbell ◽  
HF Galicia ◽  
PW Schindler
Keyword(s):  
Humic Acid ◽  
Miscible Displacement ◽  
Cd Uptake ◽  
Freeze Dried ◽  
Humic Materials ◽  
Displacement Experiments ◽  
Poorly Soluble ◽  
Solute Interactions ◽  
Displacement Approach ◽  
Adsorption Desorption

By means of the miscible-displacement approach, investigations have been carried out on cadmium adsorption-desorption by mixtures of freeze-dried montmorillonite and freshly precipitated humic acid. Low Cd surface loadings were employed and acidic (pH 4.5-5) solution conditions were maintained during both adsorption and desorption cycles. Compared with montmorillonite, Cd adsorption by humic acid was much greater so that clay-humic mixtures containing only a few per cent w/w humic acid removed appreciably more Cd from solution than that by clay alone. However, this greater Cd uptake by humic acid was offset by the susceptibility of bound Cd to desorb once the supply of Cd in the column ihput solutions was removed. Thus, both montmorillonite and undissolved humic acid had a limited ability to fix Cd, a result which may have some implication to mechanisms of Cd binding by natural clay-humic mixtures in acidic soil environments. The miscible-displacement approach appears to be well suited to examining solute interactions with poorly soluble, high molecular weight soil humic materials.

scholarly journals Influence of Nanoparticle Pretreatment on the Thermal, Rheological and Mechanical Properties of PLA-PBSA Nanocomposites Incorporating Cellulose Nanocrystals or Montmorillonite

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Wissam Abdallah ◽  
Amin Mirzadeh ◽  
Victor Tan ◽  
Musa Kamal
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanocrystals ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Butylene Succinate ◽  
Freeze Dried ◽  
Organically Modified ◽  
Spray Freeze Drying ◽  
Adsorption Desorption ◽  
Quaternary Ammonium Chloride

Nanoparticles based on cellulose nanocrystals (CNC) and montmorillonite clay (MMT) were prepared using spray freeze-drying. The nanoparticles were then used as reinforcement to prepare nanocomposites with poly(lactic acid) (PLA) as the polymer matrix. The effect of spray freeze-dried CNC (SFD-CNC) and spray freeze-dried MMT (SFD-MMT) on the rheological and mechanical properties of PLA and its blends with poly[(butylene succinate)-co-adipate)] (PBSA) were investigated. An epoxy chain extender was used during preparation of the blends and nanocomposites to enhance the mechanical properties of the products. Different methods such as scanning electron microscopy, X-ray diffraction and adsorption/desorption analyses were used to characterize the prepared nanoparticles and their localization in the blends. Dynamic oscillatory shear behavior, elongational viscosity and mechanical characteristics of the nanocomposites of PLA and the blends were evaluated. The results obtained for nanocomposites filled with unmodified SFD-MMT were compared with those obtained when the filler was a commercial organically modified montmorillonite nanoclay (methyl-tallow-bis(2-hydroxyeethyl) quaternary ammonium chloride) (C30B), which was not spray freeze-dried.

The Study of Three Capture Agents with High Efficiency for Hydrogen Sulfide

2013 ◽  
Vol 295-298 ◽  
pp. 590-593
Author(s):  
Shou Zhong Wang ◽  
Jian Zhao Qin ◽  
Yao Qing Chen ◽  
Tong Zhang ◽  
Zhi Feng Yang ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
High Efficiency ◽  
Ambient Conditions ◽  
N2 Adsorption ◽  
Removal Method ◽  
Grain Sizes ◽  
Rapid Removal ◽  
Adsorption Desorption ◽  
Desorption Method

A rapid removal method of hydrogen sulfide (H2S) gas is studied in the present paper at ambient conditions. These capture agents are powers of grain sizes and convenient for injection on H2S gas at the site of accident. The agents are characterized by SEM and N2 adsorption-desorption method, etc. The test on capturing H2S was experimented and the result indicated that the prepared agents can reduce the H2S concentration in the air to a harmless level rapidly.

Adsorption–desorption of CO2 on different type of copper oxides surfaces: Physical and chemical attractions studies

2013 ◽  
Vol 2 ◽  
pp. 8-15 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Zatil Amali Che Ramli ◽  
Mohamad Wafiuddin Ismail ◽  
Khomah Ismail ◽  
Rahimi M. Yusop ◽  
...  
Keyword(s):  
Copper Oxides ◽  
Adsorption Desorption ◽  
Physical And Chemical

Study on Porous Structure and Fractal Characteristics of Oil Shale and Semicoke

2013 ◽  
Vol 868 ◽  
pp. 276-281
Author(s):  
Li Mei Zhao ◽  
Jie Liang ◽  
Lu Xin Qian
Keyword(s):  
Porous Structure ◽  
Pore Structure ◽  
Oil Shale ◽  
Fractal Dimensions ◽  
Isothermal Adsorption ◽  
The Matrix ◽  
Fractal Characteristics ◽  
Adsorption Desorption ◽  
Desorption Method ◽  
Skeleton Structure

In order to find the change rule of porous structure of oil shale during pyrolysis, the Huadian oil shale samples were heated to final temperature of 300°C400°C500°C600°C700°C. The pore structure and pore size distribution of oil shale and produced semi-cokes were measured by N2 isothermal adsorption/desorption method. The fractal characteristics and other parameters of porous structures were then analyzed in detail. The results indicate that the pores in oil shale were open at one direction while the pores in semi-cokes could be observed from two or even four directions. The pore sizes of semi-cokes were mostly between 3-5 nm; and the pore volume increased at a quickest rate when pyrolysis temperature increased from 400 to 600 °C. Oil shale and its semi-cokes all showed obvious fractal characteristics, whereas oil shale and the semi-coke from 600 °C gave the lowest fractal dimensions; this means that the matrix of oil shale tended to keep its original skeleton structure and the pore structure of semi-cokes from high temperatures became regular after devolatilization during the pyrolysis.

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