Influence on Stucture of Layered Double Hydroxides with Different Methods Synthesis

2010 ◽  
Vol 160-162 ◽  
pp. 656-660
Author(s):  
Hong Bo Yu ◽  
Bing Xu ◽  
Ling Xi Bian ◽  
Hong Gao
Keyword(s):  
Crystallite Size ◽  
Hydrothermal Method ◽  
Layered Double Hydroxides ◽  
Target Material ◽  
Basal Spacing ◽  
Mechanochemical Method ◽  
Ft Ir ◽  
Double Hydroxides

This paper compares two methods for synthesizing a carbonate compound, Mg-Al-CO3 (Mg:Al=2:1), which is a layered double hydroxides (LDHs). The methods are mechanochemical method and hydrothermal method. The products characterized by XRD、SEM、FT-IR and TG-DTA. The results indicated that the target material was synthesized by different methods. The two kinds of well-crystallized materials with the same basal spacing d003=0.77nm, but their morphology were not same. The crystallite size of hydrothermal was larger than mechanochemistry.

Adsorption Property of MgAl-NO3 Layered Double Hydroxides to Methyl Orange

2013 ◽  
Vol 750-752 ◽  
pp. 1738-1741
Author(s):  
Jian Hui Yan ◽  
Lu Hong Zhang ◽  
You Gen Tang ◽  
Li Zhang
Keyword(s):  
Methyl Orange ◽  
Adsorption Capacity ◽  
Hydrothermal Method ◽  
Layered Double Hydroxides ◽  
Adsorption Property ◽  
Molar Ratio ◽  
Adsorption Performance ◽  
Ft Ir ◽  
Double Hydroxides

MgAl-NO3 LDHs were prepared by hydrothermal method. The as-prepared samples were characterized by SEM, XRD and FT-IR. The adsorption performance of MgAl-NO3 LDHs to methyl orange (MO) was studied. The effects of Mg/Al molar ratio on the adsorption performance of MgAl-NO3 LDHs were investigated. The results showed that the highest adsorption capacity of 499.98mg/g was obtained when the Mg/Al molar ratio was at 2.5:1.

Behavior of Layered Double Hydroxides Having Different Divalent Transition Metal Groups

2014 ◽  
Vol 563 ◽  
pp. 94-101 ◽  
Author(s):  
Mazidah Mamat ◽  
Tei Tagg ◽  
Wan Mohd Khairul ◽  
Mohd Aidil Adhha Abdullah ◽  
Norhayati Mohd Tahir ◽  
...  
Keyword(s):  
Weight Loss ◽  
Transition Metal ◽  
Layered Double Hydroxides ◽  
Divalent Cations ◽  
Precipitation Method ◽  
Basal Spacing ◽  
Highest Weight ◽  
Ft Ir ◽  
Co Precipitation ◽  
Double Hydroxides

The layered double hydroxides (LDHs) with different divalent transition metal groups and nitrate as a counter anion were investigated. Three d-block divalent metals namely cobalt (Co), nickel (Ni) and copper (Cu) were selected. The cobalt/aluminium (CoAN)-, nickel/aluminium (NiAN)- and copper/aluminium (CuAN)-layered double hydroxides were successfully synthesized via co-precipitation method. All the obtained LDHs were characterized by PXRD, FT-IR, ICP-OES, CHNS and TGA/DTG analysis. Interestingly, behavior of the LDHs was dependent on the size of divalent cations. PXRD showed the basal spacing decrease in the order NiAN (0.88nm)> CuAN (0.87nm) > CoAN (0.74nm), and in a linear correlation with the increasing radii of the divalent cations. Similar trend is observed for the weight loss of LDHs, where NiAN has the highest weight loss (53%), followed by CuAN (43%) and CoAN (34%). Further elemental analysis showed the content of trivalent metal cations, nitrate anions and water molecules in the LDHs decrease with the increasing radii.

Characterization of Chromate-Intercalated Layered Double Hydroxides

2006 ◽  
Vol 514-516 ◽  
pp. 1541-1545 ◽  
Author(s):  
Margarita del Arco ◽  
Daniel Carriazo ◽  
Cristina Martín ◽  
Amalia M. Pérez Grueso ◽  
Vicente Rives
Keyword(s):  
Layered Double Hydroxides ◽  
Thermal Analyses ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
Exchange Method ◽  
X Ray ◽  
Ft Ir ◽  
Double Hydroxides

PXRD (powder x-ray diffraction), FT-IR (Fourier Transform infrared), N2 adsorption at - 196 °C and TG/DTA (thermogravimetric and differential thermal analyses) techniques have been used for characterisation of MgAl- and ZnAl-CrO4 LDHs, which had been prepared by the ion exchange method from the corresponding chloride LDH (layered double hydroxides) precursors. The results indicates that the oxometalate intercalation in both systems produces interlayer microporosity and a basal spacing of 8.7 Å; This gallery height decreases when the samples are calcined in the temperature range 100-300 °C, due to a grafting process. A larger thermal stability is detected for MgAl-CrO4 sample than for the zinc-containing one.

scholarly journals A Comparative Study on The Adsorption Behavior of Congo Red on to ZnAl and ZnCr Layered Double Hydroxides

2020 ◽  
Vol 9 (2) ◽  
pp. 108-116
Author(s):  
Tarmizi Taher ◽  
◽  
Nyanyu Ummu Hani ◽  
Neza Rahayu Palapa ◽  
Risfidian Mohadi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Surface Area ◽  
Adsorption Kinetics ◽  
Layered Double Hydroxides ◽  
Congo Red ◽  
Adsorption Process ◽  
Bet Surface Area ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Double Hydroxides

In this work, two synthetic layered double hydroxides (LDH) consists of Zn2+ as M2+ cation with different M3+ cation, i.e., Al3+ and Cr3+ were used as an adsorbent for Congo Red removal aqueous solution. Both Zn-Al and Zn-Cr LDH were characterized by X-ray diffraction, FT-IR, and BET surface area analyzer. The effect of contact time, initial dye concentration, and temperature were evaluated in a batch technique in order to investigate the characteristic of Congo Red adsorption onto both adsorbents. The experimental data were assessed according to the parameter of adsorption kinetics, isotherm, and thermodynamics. The results of LDH characterization showed that Zn-Al LDH has a higher interlayer distance than Zn-Cr LDH, although Zn-Cr LDH has a higher surface area. The FT-IR analysis indicated the interlayer space of both Zn-Cr and Zn-Al LDH was dominated by CO32- as the interlayer anion species. The adsorption kinetics study of Congo Red on both LDH revealed that the adsorption process followed the pseudo-second-order model. For the adsorption isotherm, the experimental data fit well with the Freundlich model rather than the Langmuir model. The thermodynamic study indicated that the adsorption process that occurred on both adsorbents was spontaneous with exothermic nature.

scholarly journals Fumonisin B1 Interaction with Mg-Al and Mg-Fe Layered Double Hydroxides: Removal Efficiency and Mechanisms

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4344
Author(s):  
Jakub Matusik ◽  
Youjun Deng
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Layered Double Hydroxides ◽  
Lower Layer ◽  
Fumonisin B1 ◽  
Xrd Analysis ◽  
Layer Charge ◽  
Basal Spacing ◽  
Co Precipitation ◽  
Double Hydroxides

Mycotoxins in feed and food are highly toxic and pose a serious danger even at very low concentrations. The use of bentonites in animal diet can reduce toxin bioavailability. However, some mycotoxins like fumonisin B1 (FB1) form anionic species which excludes the use of negatively charged clays. Layered double hydroxides (LDH) with anion-exchange properties, in theory, can be perfect candidates to adsorb FB1. However, fundamental research on the use of LDH for mycotoxins removal is scarce and incomplete. Thus, the presented study was designed to explore such a possibility. The LDH materials with differing chemistry and layer charge were synthesized by co-precipitation both from metal nitrates and chlorides and were then tested for FB1 removal. XRD, FTIR, XPS, and chemical analysis were used for the LDH characterization and to obtain insight into the removal mechanisms. A higher adsorption capacity was observed for the Mg/Al LDH samples (~0.08–0.15 mol/kg) in comparison to the Mg/Fe LDH samples (~0.05–0.09 mol/kg) with no difference in removal efficiency between Cl and NO3 intercalated LDH. The adsorption capacity increased along with lower layer charge of Mg/Al and was attributed to the lower content of bonded carbonates and the increase of non-polar sites which led to matching between the adsorption domains of LDH with FB1. The FTIR analysis confirmed the negative effect of carbonates which hampered the adsorption at pH 7 and led to the highest adsorption at pH 5 (FB1 content ~15.8 ± 0.75 wt.%). The fast surface adsorption (1–2 min) was dominant and XRD analysis of the basal spacing indicated that no FB1 intercalation occurred in the LDH. The XPS confirmed a strong interaction of FB1 with Mg sites of LDH at pH 5 where the interaction with FB1 carboxylate moieties COO− was confirmed. The research confirmed a high affinity and selectivity of LDH structures towards anionic forms of FB1 mycotoxin.

scholarly journals Evaluation of Mg/Al Layered Double Hydroxides as Adsorbent Material for Adsorptive Removal of Congo Red (Acid Red 28) Azodye from Aqueous Solution

2020 ◽  
Vol 32 (9) ◽  
pp. 2381-2388
Author(s):  
LAM VAN TAN ◽  
HONG THAM NGUYEN THI ◽  
TO UYEN DAO THI ◽  
VAN THUAN TRAN
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxides ◽  
Congo Red ◽  
Organic Dyes ◽  
Synthesis Temperature ◽  
Inorganic Layer ◽  
Adsorptive Removal ◽  
Ft Ir ◽  
Ir Analysis ◽  
Double Hydroxides

The use of inorganic layer compounds as adsorbents for organic dyes in water treatment is of increasing interest. In this study, an attempt is made for the synthesis of Mg/Al LDHs by the hydrothermal method. The synthesis temperature was found to significantly affect to the structure of layered double hydroxides (LDHs), as pointed out by FT-IR analysis. In addition, an adsorption capacity of the synthesized LDHs against Congo red in aqueous solutions was investigated and also compared the adsorption results with other dyes such as methylene blue and methyl orange.

scholarly journals Modification of nano-sized layered double hydroxides by long-chain organic aliphatic surfactants

2008 ◽  
Vol 73 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Ramasamy Anbarasan ◽  
Wanduc Lee ◽  
Seung Soon
Keyword(s):  
Thermal Stability ◽  
Layered Double Hydroxides ◽  
Exchange Process ◽  
Xrd Analysis ◽  
Basal Spacing ◽  
Ion Exchange Process ◽  
Dodecanedioic Acid ◽  
Double Hydroxides ◽  
Thermal Stability Of ◽  
Long Chain

The inter-layer anion of layered double hydroxides (LDH) with a hydrotalcite (HT)-like structure was ion-exchanged with various organic surfactants, particularly with long chain aliphatic surfactants. After the ion-exchange process, the basal spacing of the LDH was increased and the increase of the basal spacing depended on various factors, such as the intercalation capacity functionality and orientation capability of the surfactant. Of the employed surfactants, stearic acid intercalated LDH showed the highest increase of the basal spacing, which was confirmed by XRD analysis. FTIR results supported the interaction of the surfactants with the LDH. In addition, an increase in the thermal stability of the dodecanedioic acid intercalated HT was evidenced by the TGA method.

scholarly journals Synthesis Of Magnesium-Aluminum Layered Double Hydroxides By Mechanochemical Method And Its Solid State Reaction Kinetics

2015 ◽  
Vol 60 (2) ◽  
pp. 1455-1457 ◽  
Author(s):  
Y. Hongbo ◽  
C. Meiling ◽  
W. Xiuhui ◽  
G. Hong
Keyword(s):  
Diffusion Process ◽  
Reaction Kinetics ◽  
Layered Double Hydroxides ◽  
Inductively Coupled Plasma ◽  
Physical Adsorption ◽  
Activation Process ◽  
Mechanochemical Method ◽  
Inductively Coupled ◽  
Xrd Patterns ◽  
Double Hydroxides

Abstract A mechanochemical method is developed in preparing magnesium-aluminum-layered double hydroxides (MgAl-LDHs). This approach includes activation process and diffusion process. In order to verify the LDHs structure and study the reaction kinetics, X-ray diffraction (XRD) patterns, inductively coupled plasma(ICP) and physical adsorption instrument were characterized. The results show that activation time can change the surface of particles and affect the reaction grade. During the diffusion process, reaction time is the most important factor. The reaction energy (ΔQ) was calculated that is 6kJ/mol.

scholarly journals Synthesis and release behavior of layered double hydroxides–carbamazepine composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ma. F. Peralta ◽  
S. N. Mendieta ◽  
I. R. Scolari ◽  
G. E. Granero ◽  
M. E. Crivello
Keyword(s):  
Layered Double Hydroxides ◽  
Release Kinetics ◽  
Sodium Cholate ◽  
Basal Spacing ◽  
Reconstruction Method ◽  
Formal Charge ◽  
Axis Parallel ◽  
Double Hydroxides ◽  
Ray Patterns ◽  
Kinetics Of

AbstractCarbamazepine (CBZ) was incorporated into layered double hydroxides (LDH) to be used as a controlled drug system in solid tumors. CBZ has a formal charge of zero, so its incorporation in the anionic clay implies a challenge. Aiming to overcome this problem, CBZ was loaded into LDH with sodium cholate (SC), a surfactant with negative charge and, for comparison, without SC by the reconstruction method. Surprisingly, it was found that both resultant nanocomposites had similar CBZ encapsulation efficiency, around 75%, and the LDH-CBZ system without SC showed a better performance in relation to the release kinetics of CBZ in simulated body fluid (pH 7.4) and acetate buffer simulating the cellular cytoplasm (pH 4.8) than the system with SC. The CBZ dimensions were measured with Chem3D and, according to the basal spacing obtained from X-ray patterns, it can be arranged in the LDH-CBZ system as a monolayer with the long axis parallel to the LDH layers. Fourier transform infrared spectroscopy and solid state NMR measurements confirmed the presence of the drug, and thermogravimetric analyses showed an enhanced thermal stability for CBZ. These results have interesting implications since they increase the spectrum of LDH application as a controlled drug system to a large number of nonionic drugs, without the addition of other components.

Room-temperature efficient NO2 gas sensors fabricated by porous 3D flower-like ZnAl-layered double hydroxides

2020 ◽  
Vol 44 (42) ◽  
pp. 18469-18480
Author(s):  
Ye Hong ◽  
Di Wang ◽  
Chong Lin ◽  
Shuiting Luo ◽  
Qingjiang Pan ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Hydrothermal Method ◽  
Gas Sensors ◽  
Layered Double Hydroxides ◽  
Room Temperature ◽  
Sodium Dodecyl ◽  
Three Dimensional ◽  
One Step ◽  
No2 Gas Sensors ◽  
Double Hydroxides

Three-dimensional (3D) flower-like zinc and aluminum-sodium dodecyl sulfate-layered double hydroxides (ZnAl-SDS-LDHs) intercalated by anions were prepared using a simple one-step hydrothermal method.

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