Preparation and Characterization of Chitosan/Hdroxy-Aluminium Pillared Montmorillonite Nanocomposites

2007 ◽  
Vol 334-335 ◽  
pp. 825-828 ◽  
Author(s):  
Wei Tan ◽  
Yi He Zhang ◽  
Yau Shan Szeto ◽  
Li Bing Liao

It was shown that chitosan and hydroxy-aluminum pillared montmorillonites were excellent materials for the removal of dyes and metal ions from effluent of dying and finishing. Chitosan/ hydroxy-aluminum pillared montmorillonite nanocomposites are expected to play a multiplex role in the treating process. In this study, the nanocomposite was prepared by incorporating hydroxy-aluminum pillared montmorillonite into chitosan solution that diluted acetic acid was used as solvent for dissolving the chitosan. The ratio of chitosan to the cationic exchange capacity of the montmorillonite was about 1:1, 2:1, 3:1, 4:1 and 6:1, respectively. The nanocomposites were characterized by XRD (X-ray diffraction), SEM (Scanning Electron Microscopy). The experimental results indicated that the presence of hydroxy-aluminum cation was in favor of the chitosan intercalation and the interlayers of MMT was intercalated with the bilayers of chitosan sheets. and they can be used in absorption of organic and metal ions for dying and finishing effluent.

2012 ◽  
Vol 510 ◽  
pp. 757-761 ◽  
Author(s):  
Shu’e Duan ◽  
Yun Hui Zhai ◽  
Ying Juan Qu

In this paper a novel colorless and salt-tolerant silver-histidine complex doped montmorillonite (Na-MMT) antibacterial agent (SHMMT) power was synthesized by ion exchange reaction using silver-histidine complex ion [Ag (his)] + as precursor, and characterized by atomic absorption spectrophotometer (AAS) and power X-ray diffraction (XRD). The antibacterial activities against Pseudoalteromonas carrageenovora were examined by a modified broth dilution test and the plate counting method. The salt-tolerant property was determined by the antibacterial activities of the sea water soaked SHMMT. The results showed that the Ag loading amount of SHMMT powder reached 1.7mmol/g, far more than the cationic exchange capacity (CEC) of Na-MMT. SHMMT powder had high bacterial activity eventhough it was soaked in the sea water for 30 days. 1


2011 ◽  
Vol 299-300 ◽  
pp. 764-769
Author(s):  
Ming Liang Yuan ◽  
Liang Yu ◽  
Jia Hua Tao ◽  
Cong Song

Natural zeolites combined with the magnetic iron oxides are prepared by a chemical coprecipitation process. A detailed characterization of our magnetically modified zeolite (MMZ) is given, including powder X-ray diffraction (XRD), nitrogen adsorption and vibrating sample magnetometer (VSM). The results reveal that in comparison with Na-zeolite, the structure of MMZ has no obvious change but its surface area increases from 25.13 m2g-1to 100.90 m2g-1. The adsorption properties of MMZ to Pb2+and Cu2+were studied. The results show that the maximum loading capacities for Pb2+and Cu2+in the initial concentration range are 123.74 and 14.633 mg g-1, respectively. The MMZ can be used as an adsorbent for removal of heavy metal ions from industrial effluents or municipal waters, and the saturated adsorbent is separated from the medium by a simple magnetic process.


2012 ◽  
Vol 727-728 ◽  
pp. 1591-1595 ◽  
Author(s):  
Aline Cadigena Lima Patrício ◽  
Marcílio Máximo da Silva ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues

Cationic surfactants, such as quaternary ammonium cations, have been used, in order to ameliorate the oil sorption capacity of inorganics materials, such as clays. Clays modified with quaternary ammonium cations (organoclays) have better performance in sorption, remove oil and grease from water at seven times the rate of activated carbon, as well as they can be used like perforation fluids of oil wells to the oil base, lubricants, among others industries. This work aims characterize the Cloisite 30B using various techniques: X-Ray Diffraction (XRD), Specific Surface Area (BET) and Cation Exchange Capacity. Different organic solvents, namely gasoline, diesel and kerosene were used in order to investigate the clays compatibility after orgophilization.


2015 ◽  
Vol 820 ◽  
pp. 51-55
Author(s):  
I.A. Silva ◽  
I.D.S. Pereira ◽  
W.S. Cavalcanti ◽  
F.K.A. Sousa ◽  
Gelmires Araújo Neves ◽  
...  

The State of Paraíba has gained prominence in the production of raw bentonite in Brazil, where a new deposit has been found in the town of Sossego-PB, besides the deposit in the town of Boa Vista-PB. With the raise in the demand, the traditional reserves are depleting after several years of exploration, and this fact may result in a higher dependence on imported clays, thus existing a great interest in the discovery and characterization of new deposits, also guaranteeing technological improvements for the region. So, the objective of this work is to characterize the new deposits of the State of Paraíba, aiming at analyzing the characteristics the prove their classification as smectitic clays. The characterization was made through the analysis of chemical composition by X-ray fluorescence (EDX), X-ray diffraction (XRD), thermogravimetric analysis and thermal differential analyses (TG and DTA), cation-exchange capacity (CEC) and specific area (SA). The results prove that the studied samples presented, in their mineralogical composition, smectite, kaolinite and quartz, besides thermal and chemical behavior typical smectitic clays.


2015 ◽  
Vol 820 ◽  
pp. 56-59
Author(s):  
F.K.A. Sousa ◽  
I.A. Silva ◽  
W.S. Cavalcanti ◽  
Gelmires Araújo Neves ◽  
Heber Carlos Ferreira

Used in various branches of the industry, bentonitic clays are considered a valuable mineral, used specially in the petroleum industry for manufacturing of fluids used the drilling of petroleum wells in long depth. Recently, a deposit of this valuable mineral was discovered in the town of Olivedos-PB. There are data that prove that this is a very poor and underdeveloped town. So, this work aims at the physico-mineralogical characterization of clays recently discovered and, this way, verify if they present similar characteristics which allow them to replace the clays from Boa Vista-PB, and if they can be used by the industry, thus bringing social development for that town. The characterization was made by means of the analysis of chemical composition by X-ray fluorescence (EDX), thermogravimetric and thermal differential analyses (TG and DTA), X-ray diffraction (XRD), cation-exchange capacity (CEC) and specific area (SA). The results show that the clays recently discovered in Olivedos-PB are polycationic clays, presenting MgO, CaO and K2O content, and that they are constituted by smectitic clay mineral, by quartz and kaolinite.


2012 ◽  
Vol 557-559 ◽  
pp. 1629-1632
Author(s):  
Xing Shun Cong ◽  
Min Li

A set of pillared montmorillonite (PILM) catalysts were prepared by exchanging Na+ with iron pillars, chromium pillars, complexes pillars of iron and chromium with different proportion, as well as complexes pillar of silica sol and iron and chromium, respectively. X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetry (TG) and differential thermal analysis (DTA) were used to characterize the catalysts. The XRD results reveal that Fe-Cr complexes pillared montmorillonites (Fe/Cr-PILM) have the basal spacing of about 2.04 nm after calcination at 300 °C for 2 h, while sole metal PILM have that of about 1.0 nm; in particular, the basal spacing of silica sol complexes pillared montmorillonite (Fe-Cr-Si-PILM) are expanded up to 4.33 nm. The TG-DTA results show that both Fe-Cr-PILM and Fe-Cr-Si-PILM have high thermal stability up to 640 °C. Catalytic activity of Fe/Cr-Si-PILM in Longkou lignite (LL) and ShengLi coal residue (SCR) liquefaction was studied, which showed that PILM had a good catalytic performance in coal conversion field.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Omnia A. A. El-Shamy ◽  
Ragaa E. El-Azabawy ◽  
Olfat. E. El-Azabawy

Superparamagnetic magnetite-alginate nanoparticles (M-AlgNPs) were synthesized utilizing a coprecipitation method. Then, the prepared M-AlgNPs were characterized via Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy (XRD) to affirm the formation and the crystallinity of this composite. In addition, the surface morphology of the prepared nanoparticles was inspected by transmission electron microscopy (TEM) which revealed well-dispersed nanoparticles of Fe3O4 into alginate. The adsorption characteristics of the synthesized nanoparticles for removing Ni+2 and Co+2 from wastewater were evaluated via atomic absorption measurements (AAS). The elimination efficiency of the M-AlgNPs was detected at pH=7 in 100 ppm (initial concentration) of Ni+2 and Co+2, separately. The M-AlgNPs provided the maximum equilibrium uptake percentage for Ni+2 and Co+2 of 97.88 and 95.01%, respectively. The adsorption of Ni+2 and Co+2 onto the M-AlgNP surface was found to fit the Langmuir model with R2 values higher than that obtained from the Freundlich model for both metal ions. Moreover, RL “separating factor” for the adsorption process was assessed and found to be less than unity; this expresses the higher ability of the investigated metal ions to be adsorbed onto the M-AlgNP surface. The adsorption method was discovered to be pH-dependent and well-suited to the isothermal equations of Langmuir and Freundlich. For regeneration studies, M-AlgNPs have been investigated and results confirmed that it could be reused with effective sorption capacity over three cycles.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 902F-902
Author(s):  
Mana Libran ◽  
David J. Williams

Leca clay pebbles were characterized and tested as a possible growing-medium for use in floriculture production systems that recycle irrigation water. Leca clay pebbles are light porous particles made by heating clay. X-ray diffraction tests indicate that high manufacturing temperatures (1100C) result in final particles composed primarily of quartz. Water-holding capacity was determined by pressure plate apparatus at eight pressures. Leca particles that were 4 to 8 mm retained more water than particles sized 12 to 18 mm. The bulk density of the particles were 0.43 and 0.37 g/cc for the 48-mm and the 12- to 18-mm particles, respectively. The pH of the leca particles was 7.77. The cation exchange capacity of the leca particles was relatively low compared to a standard soilless growing medium of 1 pine bark: 1 peat: 1 perlite (by volume). Leca particles have a CEC of o.82 me/100 g Ca and 6.36 me/100 g K, where the CEC of the previously mentioned soilless.medium was 24.21 me/100g Ca and 30.08 me/100 g K. Leca clay pebbles were tested as growing medium for the production of geraniums (Pelargonium hortorum) stock plants.


2017 ◽  
Vol 76 (8) ◽  
pp. 2232-2241 ◽  
Author(s):  
Jock Asanja Alexander ◽  
Abdulsalam Surajudeen ◽  
El-Nafaty Usman Aliyu ◽  
Aroke Umar Omeiza ◽  
Muhammad Abbas Ahmad Zaini

The present work was aimed at evaluating the multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) ions onto natural bentonite. The bentonite clay adsorbent was characterized for physical and chemical properties using X-ray diffraction, X-ray fluorescence, Brunauer–Emmett–Teller surface area and cation exchange capacity. The column performance was evaluated using adsorbent bed height of 5.0 cm, with varying influent concentrations (10 mg/L and 50 mg/L) and flow rates (1.4 mL/min and 2.4 mL/min). The result shows that the breakthrough time for all metal ions ranged from 50 to 480 minutes. The maximum adsorption capacity was obtained at initial concentration of 10 mg/L and flow rate of 1.4 mL/min, with 2.22 mg/g of lead(II), 1.71 mg/g of cadmium(II) and 0.37 mg/g of manganese(II). The order of metal ions removal by natural bentonite is lead(II) > cadmium(II) > manganese(II). The sorption performance and the dynamic behaviour of the column were predicted using Adams–Bohart, Thomas, and Yoon–Nelson models. The linear regression analysis demonstrated that the Thomas and Yoon–Nelson models fitted well with the column adsorption data for all metal ions. The natural bentonite was effective for the treatment of wastewater laden with multi-metals, and the process parameters obtained from this work can be used at the industrial scale.


1965 ◽  
Vol 2 (4) ◽  
pp. 299-308 ◽  
Author(s):  
R. S. La Venture ◽  
B. P. Warkentin

Measurements of soluble components, and characterization of the charge on the mineral surfaces, are reported for five samples of the Champlain Sea sediments. Large amounts of magnesium, beyond the amount of dolomite present, were slowly released in solution from the broken surfaces of the minerals. Amorphous aluminosilicates made up less than 6% of the sample weight, and their removal did not improve the X-ray diffraction patterns or alter significantly the chemical properties of the sediments. Of the cation exchange capacity of 20 to 30 meq/100 g at pH 7, from 50 to 75% was found to be due to pH-dependent charge, which leads to preferential adsorption of monovalent ions. In equilibrium with artificial seawater, the samples had from 50 to 25% exchangeable sodium.


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