Preparation and Characterization of Aluminum Lithium Hydroxide Carbonate Hydrate Obtained From Basic Aluminum Sulfate

2012 ◽  
Vol 1372 ◽  
Author(s):  
César A. C. Soto ◽  
Aurora P. Delgado ◽  
Esthela R. Ramírez ◽  
Veridiana R. Zamudio
Keyword(s):  
Electron Microscopy ◽  
Aluminum Sulfate ◽  
Homogeneous Solution ◽  
Lithium Carbonate ◽  
Sodium Aluminate ◽  
Lithium Hydroxide ◽  
Transmission Electron ◽  
Aluminum Lithium ◽  
Double Hydroxide ◽  
Basic Aluminum

ABSTRACTAluminum lithium hydroxide carbonate hydrate, also known as Al-Li double hydroxide or Al-Li hydrotalcite-like compound [Al2Li(OH)6]2CO3•nH2O, was prepared from basic aluminum sulfate. This compound was prepared by precipitation in homogeneous solution of an aluminum bisulfite solution. A sodium aluminate aqueous solution was prepared by dissolving basic aluminum sulfate in 1M sodium hydroxide. The Al-Li double hydroxide was obtained after addition of lithium carbonate satured solution to the sodium aluminate solution, at 60 °C. The synthesized powder was characterized by thermal analysis (TG, DTG and DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By this method crystalline Li-Al hydrotalcite like compound with composition near to Al4Li2(OH)12CO3 •3H2O was obtained.

Preparation of Lithium Aluminum Layered Double Hydroxide from Ammonium Dawsonite and Lithium Carbonate

2012 ◽  
Vol 1481 ◽  
pp. 29-36
Author(s):  
C. A. Contreras Soto ◽  
E. Ramos-Ramírez ◽  
V. Reyes Zamudio ◽  
J. I. Macías
Keyword(s):  
Layered Double Hydroxide ◽  
Lithium Carbonate ◽  
Lithium Hydroxide ◽  
Lithium Aluminum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Aluminum Lithium ◽  
Different Temperatures ◽  
Double Hydroxide

ABSTRACTAluminum lithium hydroxide carbonate hydrate, also known as Al/Li layered double hydroxide or Al-Li hydrotalcite-like compound [Al2Li(OH)6]2CO3•nH2O, was prepared by reaction of lithium carbonate with ammonium dawsonite [NH4Al(OH)2CO3]. The reaction of ammonium dawsonite with a lithium carbonate satured solution at different temperatures and lithium carbonate concentrations was studied. The obtained solids were characterized by differential thermal analysis (DTA), thermogravimetry (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). By this method, crystalline Li/Al LDH [Al2Li(OH)6]2CO3·3H2O can be obtained at 60 °C and 4 h reaction time.

scholarly journals Preparation and Characterization of Polyhydroxybutyrate/Polycaprolactone Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Cha Ping Liau ◽  
Mansor Bin Ahmad ◽  
Kamyar Shameli ◽  
Wan Md Zin Wan Yunus ◽  
Nor Azowa Ibrahim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Basal Spacing ◽  
Cooh Group ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Ion Exchange Reaction ◽  
Transmission Electron ◽  
Matrix Enhancement ◽  
Double Hydroxide

Polyhydroxybutyrate (PHB)/polycaprolactone (PCL)/stearate Mg-Al layered double hydroxide (LDH) nanocomposites were prepared via solution casting intercalation method. Coprecipitation method was used to prepare the anionic clay Mg-Al LDH from nitrate salt solution. Modification of nitrate anions by stearate anions between the LDH layers via ion exchange reaction. FTIR spectra showed the presence of carboxylic acid (COOH) group which indicates that stearate anions were successfully intercalated into the Mg-Al LDH. The formation of nanocomposites only involves physical interaction as there are no new functional groups or new bonding formed. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the mixtures of nanocomposites are intercalated and exfoliated types. XRD results showed increasing of basal spacing from 8.66 to 32.97 Å in modified stearate Mg-Al LDH, and TEM results revealed that the stearate Mg-Al LDH layers are homogeneously distributed in the PHB/PCL polymer blends matrix. Enhancement in 300% elongation at break and 66% tensile strength in the presence of 1.0 wt % of the stearate Mg-Al LDH as compare with PHB/PCL blends. Scanning electron microscopy (SEM) proved that clay improves compatibility between polymer matrix and the best ratio 80PHB/20PCL/1stearate Mg-Al LDH surface is well dispersed and stretched before it breaks.

Enhanced Specific Heat of Silica Nanofluid

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Donghyun Shin ◽  
Debjyoti Banerjee
Keyword(s):  
Electron Microscopy ◽  
Specific Heat ◽  
Unit Volume ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Carbonate ◽  
Sem Image ◽  
Surface Energies ◽  
Transmission Electron ◽  
The Stability

Silica nanoparticles (1% by weight) were dispersed in a eutectic of lithium carbonate and potassium carbonate (62:38 ratio) to obtain high temperature nanofluids. A differential scanning calorimeter instrument was used to measure the specific heat of the neat molten salt eutectic and after addition of nanoparticles. The specific heat of the nanofluid was enhanced by 19–24%. The measurement uncertainty for the specific heat values in the experiments is estimated to be in the range of 1–5%. These experimental data contradict earlier experimental results reported in the literature. (Notably, the stability of the nanofluid samples was not verified in these studies.) In the present study, the dispersion and stability of the nanoparticles were confirmed by using scanning electron microscopy (SEM). Percolation networks were observed in the SEM image of the nanofluid. Furthermore, no agglomeration of the nanoparticles was observed, as confirmed by transmission electron microscopy. The observed enhancements are suggested to be due to the high specific surface energies that are associated with the high surface area of the nanoparticles per unit volume (or per unit mass).

scholarly journals Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yun Zhao ◽  
Fenfei Xiao ◽  
Qingze Jiao
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Layered Double Hydroxide ◽  
Hydrothermal Reaction ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Double Hydroxide ◽  
Scanning Electron

Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al LDHs could be obtained when the pH value was about 10.0 with a long reaction time (12–18 h) at 180°C.

Polyoxometalate and copolymer-functionalized ionic liquid catalyst for esterification

2011 ◽  
Vol 84 (3) ◽  
pp. 541-551 ◽  
Author(s):  
Huan Li ◽  
Jizhong Chen ◽  
Li Hua ◽  
Yunxiang Qiao ◽  
Yinyin Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ionic Liquid ◽  
Fourier Transform ◽  
Room Temperature ◽  
Homogeneous Solution ◽  
Imidazolium Cation ◽  
Transmission Electron ◽  
Ft Ir ◽  
Halogen Free

A new room-temperature ionic liquid (RTIL) consisting of a polyoxometalate (POM) anion and tri-block copolymer (P123)-functionalized imidazolium cation was synthesized and utilized as a halogen-free catalyst for esterification. The catalytic system was a homogeneous solution at the beginning of the reaction, but an emulsion formed during the course of the reaction, and a progressive phase separation of the catalyst occurred at 0 °C over the course of 3 h. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier transform/infrared spectroscopy (FT/IR) have been used to characterize the properties of the IL during the reaction. The new IL catalyst was found to be highly efficient in the esterification of various alcohols and can be recycled at least seven times.

Tunable Morphologies of Co2+-Doped Zno/Znal2O4 Composite Films Derived from Co2+-Substituted Layered Double Hydroxide Single Source Precursor

2012 ◽  
Vol 455-456 ◽  
pp. 825-829
Author(s):  
Rui Yin ◽  
Lan Yang ◽  
Sai Long Xu
Keyword(s):  
Electron Microscopy ◽  
Layered Double Hydroxide ◽  
Composite Films ◽  
Single Source ◽  
Subsequent Transformation ◽  
Transmission Electron ◽  
Single Source Precursor ◽  
Doped Zno ◽  
Double Hydroxide ◽  
Deposited Film

Co2+-doped ZnO/ZnAl2O4 composite films have been prepared by facile calcination of a single-source CoIIZnIIAlIII-layered double hydroxide (CoIIZnIIAlIII-LDH) precursor. The preparation was performed initially by cast aqueous precursor slurry on quartz glass substrate and subsequent transformation to a network-like film via calcination. The surface morphology and composition of the resulting films were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and XPS analyses. The results clearly indicated that the as-deposited film is composed of Co2+-doped ZnO and ZnAl2O4, and also large ZnO single crystals are homogeneously incorporated into small ZnAl2O4 particle matrix. The influence of Co2+-doping concentration on microstructure and also on optical properties of the composite films was also investigated.

scholarly journals The Influence of the Electrodeposition Parameters on the Properties of Mn-Co-Based Nanofilms as Anode Materials for Alkaline Electrolysers

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2662
Author(s):  
Karolina Cysewska ◽  
Maria Krystyna Rybarczyk ◽  
Grzegorz Cempura ◽  
Jakub Karczewski ◽  
Marcin Łapiński ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Nickel Foam ◽  
Catalytic Performance ◽  
X Ray ◽  
Synthesis Conditions ◽  
Β Phase ◽  
Metal Nitrates ◽  
Transmission Electron ◽  
Double Hydroxide

In this work, the influence of the synthesis conditions on the structure, morphology, and electrocatalytic performance for the oxygen evolution reaction (OER) of Mn-Co-based films is studied. For this purpose, Mn-Co nanofilm is electrochemically synthesised in a one-step process on nickel foam in the presence of metal nitrates without any additives. The possible mechanism of the synthesis is proposed. The morphology and structure of the catalysts are studied by various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analyses show that the as-deposited catalysts consist mainly of oxides/hydroxides and/or (oxy)hydroxides based on Mn2+, Co2+, and Co3+. The alkaline post-treatment of the film results in the formation of Mn-Co (oxy)hydroxides and crystalline Co(OH)2 with a β-phase hexagonal platelet-like shape structure, indicating a layered double hydroxide structure, desirable for the OER. Electrochemical studies show that the catalytic performance of Mn-Co was dependent on the concentration of Mn versus Co in the synthesis solution and on the deposition charge. The optimised Mn-Co/Ni foam is characterised by a specific surface area of 10.5 m2·g−1, a pore volume of 0.0042 cm3·g−1, and high electrochemical stability with an overpotential deviation around 330–340 mV at 10 mA·cm−2geo for 70 h.

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