Stabilization of Dicalcium Silicate-Zn Composite Approaching Layered Double Hydroxide Structure for Bioactive Cement Applications

2022 ◽  
Author(s):  
Hind Agourrame ◽  
Amine Belafhaili ◽  
Nisrine El Fami ◽  
Nacer Khachani ◽  
Mohamed Alami Talbi ◽  
...  
Keyword(s):  
Acid Solution ◽  
Layered Double Hydroxide ◽  
S Phase ◽  
Dicalcium Silicate ◽  
Metal Salts ◽  
Basic Solution ◽  
Silicate Phase ◽  
Edax Analysis ◽  
Co Precipitation ◽  
Double Hydroxide

Layered Double Hydroxide (LDH) is ionic clay that is characterized by the union of metal cations and OH- hydroxides. LDH composites exhibit considerably high releasing and recharging capacity and have applications as bioactive cements. They can be prepared by direct co-precipitation of metal salts at controlled pH. The preparation is carried out from an acid solution of Zn (NO3)2.6H2O, Al (NO3)3.9H2O and a basic solution of Na2CO3 and NaOH, with a Zn/Al ratio = 3, the pH is stabilized between 9 and 9.5 at a constant temperature of 45°C. The objective of this study is to incorporate Zinc and Aluminum elements at different percentages in dicalcium silicate phase to produce C2S phase incorporating LDH composite. The characterizations of the developed phases by XRD and SEM indicate the formation of stoichiometric LDH phases Zn6Al2(OH)16CO3.4H2O and non-stoichiometric Zn0.61Al0.39 (OH)2(CO3)0.195.xH2O, the incorporation of Zn in the belitic C2S phase and not Al. The obtained micrographs by SEM(EDAX) analysis show new morphology of the stabilized composite.

scholarly journals Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana, and Feldspar: Batch experiments

2011 ◽  
Vol 17 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Aiman Al-Rawajfeh ◽  
Khaldoon Al-Whoosh ◽  
Dwairi Al ◽  
Ahmad Al-Maaberah ◽  
Amer Tarawneh
Keyword(s):  
Layered Double Hydroxide ◽  
Metal Ion ◽  
Raw Materials ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Considerable Potential ◽  
Ion Concentrations ◽  
Pre Treatment ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, composites of layered double hydroxide (LDH) with three Jordanian natural raw materials; Tripoli (T), Pozzolana (P) and Feldspar (F) were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ?Go were negative and within 21 to 26 KJ/mol, while the values of ?Ho and ?So were positive and within the range of 0.1 to 25 KJ/mol. The values of ?H?, ?S?, and ?G? indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

An elegant synthesis of chitosan grafted hydrotalcite nano-bio composite material and its effective catalysis for solvent-free synthesis of jasminaldehyde

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94562-94570 ◽  
Author(s):  
Jacky H. Adwani ◽  
Noor-ul H. Khan ◽  
Ram S. Shukla
Keyword(s):  
Composite Material ◽  
Layered Double Hydroxide ◽  
Solvent Free ◽  
Precipitation Method ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Solvent Free Synthesis

A novel nano-bio composite of chitosan and a layered double hydroxide elegantly synthesized by a co-precipitation method had effectively and selectively catalysed the jasminaldehyde synthesis.

Cu/Al Layered Double Hydroxide by Co-precipitation with High Anti-UV Performance in Waterborne Varnish

2019 ◽  
Vol 48 (8) ◽  
pp. 866-869
Author(s):  
Xiuxiu Han ◽  
Shuhua Zhang ◽  
Jingjing Lu ◽  
Yingying Ma ◽  
Nengshuo Fu ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Co Precipitation ◽  
Double Hydroxide

scholarly journals Structural Stability of Ni/Al Layered Double Hydroxide Supported on Graphite and Biochar Toward Adorption of Congo Red

2021 ◽  
Vol 6 (2) ◽  
pp. 85-95
Author(s):  
Patimah Mega Syah Bahar Nur Siregar ◽  
Neza Rahayu Palapa ◽  
Alfan Wijaya ◽  
Erni Salasia Fitri ◽  
Aldes Lesbani
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Layered Double Hydroxide ◽  
Congo Red ◽  
High Performance ◽  
Precipitation Method ◽  
First Order ◽  
Xrd Diffraction ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, Ni/Al layered double hydroxide (LDH) was modified by using co-precipitation method to generate Ni/Al-graphite (Ni/Al-GF) and Ni/Al-biochar (Ni/Al-BC). The adsorbents were applied to remove Congo Red from aqueous solution. The obtained samples were characterized by using XRD, FTIR, BET and TG-DTA. The XRD diffraction pattern of Ni/Al LDH, Ni/Al-GF, and Ni/Al-BC presented the formation of composite with decreasing crystallinity. The surface area modified LDHs was higher than the pristine materials, which was obtained 15.106 m2/g, 21.595 m2/g and 438.942 m2/g for Ni/Al-LDH, Ni/Al-GF, Ni/Al-BC respectively. The adsorption of Congo Red on the materials was tested at diferent parameters and the results exhibited that Congo Red adsorption on LDHs were pseudo-first-order (PFO) kinetic, spontaneous, endothermic and followed Langmuir model. The adsorbents removed Congo Red by high performance stability with adsorption capacity was 116.297 mg/g for Ni/Al-GF and 312.500 mg/g for Ni/Al-BC. These adsorption capacity was higher than the pristine LDH (61.728 mg/g). The regeneration process which carried out for five cycles showed that Ni/Al-GF and Ni/Al-BC have stable structures as reuse adsorbents for Congo Red from aqueous solution.

scholarly journals CONVERSION OF STYRENE INTO BENZALDEHYDE AND STYRENE EPOXIDE OVER MgCoAl-LDH CATALYSTS

2017 ◽  
Vol 55 (4) ◽  
pp. 403 ◽  
Author(s):  
Nguyen Tien Thao ◽  
Dang Van Long ◽  
Dinh Minh Hoan
Keyword(s):  
Active Sites ◽  
Styrene Oxide ◽  
Metal Salts ◽  
Experimental Conditions ◽  
Cobalt Ions ◽  
Styrene Epoxide ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Very High ◽  
Styrene Conversion

Co-containing hydroxides have been successfully synthesized by the co-precipitation of starting-metal salts. The obtained materials were characterized by some physical means including XRD, EDS, BET… It is found that Co2+ ions are present in the layered double hydroxide (LDH) sheets. The presence of cobalt ions in LDH plays as active sites for the oxidation of styrene with air. The catalysts exhibited a very high activity in the conversion of styrene into two main products (benzaldehyde and styrene oxide). The highest styrene conversion is about 90-95% and the total selectivity to benzaldehyde and styrene oxide is in the range of 80-85% under reported experimental conditions.

scholarly journals Photodecolourization of congo red dye in presence of Ni3+ layered double hydroxide

2021 ◽  
Vol 30 ◽  
pp. 02010
Author(s):  
Irina Ryltsova ◽  
Evgenia Tarasenko ◽  
Olga Lebedeva
Keyword(s):  
Layered Double Hydroxide ◽  
Congo Red ◽  
Uv Light ◽  
Order Kinetic ◽  
X Ray ◽  
Congo Red Dye ◽  
Order Kinetic Model ◽  
Co Precipitation ◽  
Red Dye ◽  
Double Hydroxide

Layered double hydroxide containing Ni3+ (Mg/AlNi-LDH) was successfully synthesized by co-precipitation in an oxidizing media. The resulted product was characterized using X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry. The activity of Mg/AlNi-LDH in the process of photodegradation of Congo red dye using UV light irradiation was evaluated. The initial rate of photodegradation of the dye in the presence of LDH is 1.6 times higher than that of UV irradiated solution. The kinetic data obtained for photodegradation process can be adequately described by pseudo-first-order kinetic model. The presence of Mg/AlNi – LDH leads to increased photodegradation yield compared to destruction only by UV irradiation.

Fabrication of TiO2@ZnAl-layered double hydroxide based anode material for dye-sensitized solar cell

RSC Advances ◽  
2016 ◽  
Vol 6 (13) ◽  
pp. 10912-10918 ◽  
Author(s):  
Leila Jafari Foruzin ◽  
Zolfaghar Rezvani ◽  
Kamellia Nejati
Keyword(s):  
Solar Cell ◽  
Anode Material ◽  
Layered Double Hydroxide ◽  
Dye Sensitized Solar Cell ◽  
Precipitation Method ◽  
Dye Sensitized ◽  
Co Precipitation ◽  
Double Hydroxide

A TiO2@ZnAl-layered double hydroxide nanocomposite was prepared by the co-precipitation method; then, the product was calcined in order to obtain the TiO2@MMO nanocomposite, and use as anode material in dye-sensitized solar cell (DSSC).

Structural, thermal and mechanical properties of polymer nanocomposites based on organosoluble polyimide with naphthyl pendent group and layered double hydroxide

2016 ◽  
Vol 29 (8) ◽  
pp. 951-959 ◽  
Author(s):  
Mohammad Dinari ◽  
Ahmad Reza Rajabi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Layered Double Hydroxide ◽  
In Situ Polymerization ◽  
Zinc Nitrate ◽  
Precipitation Reaction ◽  
Nitrate Hexahydrate ◽  
Pendent Group ◽  
Co Precipitation ◽  
Double Hydroxide

In this study, a soluble aromatic polyimide (PI) with naphthyl pendent group was initially synthesized by the reaction of pyromellitic dianhydride (PMDA) with 5-methyl- N,N-bis(4-nitrophenyl)naphthalen-1-amine. Then, via co-precipitation reaction of zinc nitrate hexahydrate and chromium nitrate nonahydrate, Zn/Cr-layered double hydroxide (LDH) was synthesized using hydrothermal techniques. Finally, different novel nanocomposites (NCs) based on PI and Zn/Cr-LDH (1, 2, 4 wt%) were produced through in situ polymerization. The resulting materials were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetry analysis (TGA), field emission scanning electron microscopy, transmission electron microscopy, and mechanical testing. According to the TGA results, the prepared NCs showed high thermal stability at higher temperature due to the good dispersion and homogeneity of Zn/Cr-LDH in polymeric matrix. Consequently, the mechanical properties of the synthesized NCs were enhanced by the incorporation of 2 wt% Zn/Cr-LDH in the polymer matrix.

scholarly journals Oxidation of Cysteinate Anions Immobilized in the Interlamellar Space of CaAl-Layered Double Hydroxide

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1202
Author(s):  
Zita Timár ◽  
Truong Ngoc Hung ◽  
Cora Pravda ◽  
Zoltán Kónya ◽  
Ákos Kukovecz ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Room Temperature ◽  
Precipitation Method ◽  
Confined Space ◽  
Oxidation Reactions ◽  
Sulfenic Acid ◽  
X Ray ◽  
Mild Conditions ◽  
Co Precipitation ◽  
Double Hydroxide

L-Cysteinate-intercalated CaAl-layered double hydroxide (LDH) was prepared by the co-precipitation method producing highly crystalline hydrocalumite phase with a well-pillared interlayer gallery. The obtained materials were characterized by X-ray diffractometry, IR as well as Raman spectroscopies. By performing interlamellar oxidation reactions with peracetic acid as oxidant, oxidation of cysteinate to cystinate in aqueous and cysteinate sulfenic acid in acetonic suspensions occurred. The oxidations could be performed under mild conditions, at room temperature, under neutral pH and in air. It has been shown that the transformation pathways are due to the presence of the layered structure, that is, the confined space of the LDH behaved as molecular reactor.

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