Aluminum Nitrate Research Articles

Improved Electroactive β Phase Nucleation and Dielectric Properties of P(VDF-HFP) Composite with Al(NO3)3·9H2O Fillers

In this study, the poly (vinylidene fluoride-hexafluoropropylene) P(VDF-HFP) film is facilely prepared by the solution casting technique. The effect of aluminum nitrate nonahydrate (Al(NO3)3·9H2O) on the crystalline phase and dielectric behavior of P(VDF-HFP) composite films is systematically investigated. Experimental results founded that the P(VDF-HFP) composite films exhibit the micro-pores structure on the top surface. Addition of the Al(NO3)3·9H2O filler is found to enhance the electroactive β phase by about 20%. Furthermore, the dielectric constants of pure P(VDF-HFP) and P(VDF-HFP)/1.5 wt.% Al(NO3)3·9H2O films are derived as 8 and 28, respectively. These results indicate that the Al(NO3)3·9H2O hydrated salt acts as the nucleation agent to produce the crystallization of the β phase resulted in improved dielectric constant in P(VDF-HFP) composite films.

Microstructure and phase formation of mullite-Pr6O11 composite prepared by spark plasma sintering

The present work investigates the effect of high praseodymium oxide (Pr6O11) content on the microstructure and phase formation of mullite (3Al2O3·2SiO2) precursor by means of the spark plasma sintering process. 30 wt% Pr6O11 was added to a mullite precursor consisting of aluminum nitrate nonahydrate and tetraethyl orthosilicate through a high energy mixer mill in ethanol media. The spark plasma sintering was performed at a temperature of 1200 °C under 23 Pa vacuum conditions by applying initial and final pressure of 10 and 30 MPa, respectively. XRD analysis confirms the existence of mullite, alumina, Pr6O11, Pr2O3 and quartz as the only crystalline phases. FESEM images reveal an interesting deposition of hexagonal-shaped Al2O3 particles on polished surfaces and complex oxide phases of the fiber network adhering to alumina particles in the form of tails seen on the fracture surfaces. Moreover, the bending strength of 213 ± 21 MPa, Vickers hardness of 9.3 ± 0.1 MPa and fracture toughness of 6.21 ± 0.12 MPa ·m1/2 are obtained for the prepared composite.

Utilizing a Long Short-Term Memory Algorithm Modified by Dwarf Mongoose Optimization to Predict Thermal Expansion of Cu-Al2O3 Nanocomposites

This paper presents a machine learning model to predict the effect of Al2O3 nanoparticle content on the coefficient of thermal expansion in Cu-Al2O3 nanocomposites prepared using an in situ chemical technique. The model developed is a modification of Long Short-Term Memory (LSTM) using dwarf mongoose optimization (DMO), which mimics the behavior of DMO to find its food for predicting the behavior of the composite. The swarm of DMO consists of three groups, namely the alpha group, scouts, and babysitters. Each group has its own behavior to capture the food. The preparation of the nanocomposite was performed using aluminum nitrate that was added to a solution containing scattered copper nitrate. After that, the powders of CuO and Al2O3 were obtained, and the leftover liquid was removed using thermal treatment at 850 °C for 1 h. The powders were consolidated using compaction and sintering processes. The impact of Al2O3 contents on the thermal properties of the Cu-Al2O3 nanocomposite was investigated. The results showed that the Thermal Expansion Coefficient (TEC) decreases with increasing Al2O3 content due to the increased precipitation of Al2O3 nanoparticles at the grain boundaries of the Cu matrix. Moreover, the good interfacial bonding between Al2O3 and the Cu may participate in this decrease in TEC. The proposed machine learning model was able to predict the TEC of all the produced composites with different Al2O3 content and was tested at different temperatures with very good accuracy, reaching 99%.

Performance analysis of aqueous Al-ion electrolyte based dye sensitized solar cell

Photovoltaic performance of the aqueous Al-ion electrolyte-based dye-sensitized solar cells (DSSCs) was investigated by varying the aluminium nitrate concentration, ranging from 0.02 to 0.1 M and using Eosin-Y (EY) sensitized antimony-doped tin oxide (ATO) photoanode with platinum (Pt) as counter electrode. Photoconversion efficiency (PCE) peaks for 0.1 M using the source of 100 mW cm−2 with AM 1.5G (standard) solar simulator under ambient condition, photocurrent density (JSC) reaches 3.76 mA/cm2 and efficiency (PCE, η) 3.17%. Most of the work that exist in literature with (K, Na, Co, Li, etc. based) aqueous electrolyte quoted the maximum efficiency 1.55% whereas, the present work with pure aqueous Al-ion electrolyte gives 50% of higher efficiency over the quoted value. Moreover compared to the undoped tin oxide photoanode, this work with Sb doped tin oxide shows an enhancement of efficiency about 80%.

Synthesis and characterization of nano α-alumina by an inorganic sol–gel method

This work aimed at the synthesis of nano α-alumina by an inorganic sol–gel method and subsequent calcination at 1,200 °C. The concentration of the precipitating agent (sodium hydroxide) and the order of reaction were varied, resulting in aluminum hydroxide. Aluminum chloride and aluminum nitrate were used as precursors. After synthesis, the samples were calcined at 1,200 °C for 1 h to obtain the desired nano alumina phase. The alumina powders were analyzed by DSC/TG, XRD, DLS, zeta potential, FTIR, FESEM and BET techniques. As a result, the use of 12 M NaOH and aluminum chloride and nitrate dripped simultaneously yielded 89 % Al(OH)3 and 58 % Al2O3 after calcination. Nano α-alumina was obtained by a simple method using salts as precursors and a final calcination.

Solution-Processed Organic Photodetectors with Renewable Materials.

An organic photodetector prepared by a simple solution method based on renewable citrus pectin with an optimized concentration of aluminum nitrate (AlC05) is introduced herein. The effects of different concentrations of aluminum nitrate on the morphology and optical properties were investigated through various characterization methods. An AlC concentration of 0.5 mg/mL was found to provide the highest on/off ratio and acceptable rise and decay times. Also, the optimized device (Al/AlC0.5/ITO) exhibited good stability and repeatability at a 0.1 V bias under 440 nm visible light. Based on these results, citrus pectin materials were successfully used to fabricate an organic photodetector with a simple and cost-efficient fabrication process, while taking into account environmental commitments.

Effects of Aluminum Oxide Addition on Electrical and Mechanical Properties of 3 mol% Yttria-Stabilized Tetragonal Zirconia Electrolyte for IT-SOFCs.

Composite tetragonal zirconia (3Y-TZP) sinters with Al2O3 contents of 0, 1, 5, 10 and 15 mol% were obtained from a 3-YSZ powder prepared using the gelatin method, and the influence of alumina addition on the mechanical and electrical properties of the obtained sinters was investigated. Al2O3 was added via two different methods, namely during the preparation of the 3-YSZ powder and via impregnation using an alcohol solution of aluminum nitrate. The obtained green bodies were sintered for 2 h in air at 1773 K. The structure and morphology of the two series of sinters were investigated using XRD and SEM-EDS, their electrical properties were determined using impedance spectroscopy, and their hardness and critical stress intensity factor were measured using the Vickers indentation test. We established that both the amount of alumina and the method used to introduce it into the 3Y-TZP matrix significantly affect the physicochemical properties of the obtained polycrystalline material. The 3-YSZ/10 mol% Al2O3 sinter that had Al2O3 introduced during the preparation of the 3-YSZ powder was found to exhibit the most advantageous mechanical and electrical properties while still having sufficiently low porosity.

Fabrication of AZO and FAZO films using low-cost spin-coating method

This paper proposes a spin coating method to investigate the use of Al-doped ZnO (AZO) and F, Al co-doped ZnO (FAZO) films using zinc acetate as a zinc source and aluminum nitrate and ammonia fluoride as the dopant. Different processing temperatures have been conducted in-depth research on the AZO and FAZO thin film structures, morphology and photoelectric properties. The results show that for the AZO film, the intensity of the (002) diffraction peak (DP) first increases and then decreases with temperature, while the intensity of the (002) DP of the FAZO film gradually increases with temperature, effectively improving the thermal stability of the prepared AZO film. With the incorporation of F, the optimum growth of ZnO films along the c-axis perpendicular to the substrate surface is promoted, and the grain size on the film surface increases. Meanwhile, the introduction of F inhibits the generation of interstitial Zn atoms, O vacancy, and Zn vacancy; reduces the adsorption of –CO3, H2O, OH−, and O2 on the surface; and significantly improves the film stability. The optimum electrical resistivity (ρ) values of FAZO and AZO films prepared at 450 °C are 3.32 × 10−3 Ωcm and 5.66 × 10−3 Ωcm, respectively, and the average transmittance (TA) within the range of 380–1600 nm is 92.84% and 88.65%, respectively.

Impact of the aluminum species state on Al pairs formation in the ZSM-5 framework

The aluminum (Al) pairs in the ZSM-5 zeolite framework are recognized as an important acid site for a variety of reactions. However, knowledge of how to prepare ZSM-5 zeolites with adjustable Al pairs contents is still lacking. In this work, the impact of the Al species state and concentration on the content of the Al pairs in the preparation of ZSM-5 zeolite was studied. First, we prepared ZSM-5 zeolites with the same SDA (TPAOH), Si source (TEOS), and crystallization condition but with different Al sources (aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum hydroxide, and sodium aluminate). The Raman spectra indicated that the state of the Al species in the silicon aluminum mixture differs for Al[(OH2)6]3+ and Al(OH)4–. Although the prepared ZSM-5 zeolites have similar Si/Al molar ratios, the silicon aluminum mixture with Al(OH)4– is more likely to form Al pairs than the silicon aluminum mixture with Al[(OH2)6]3+ (74% vs. 52%). This conclusion was further proven by well-designed control experiments. For experiments with the same Al source (aluminum sulfate), SDA (TPAOH), Si source (TEOS), and crystallization condition, the conversion of the Al species from Al[(OH2)6]3+ to Al(OH)4– was achieved by the addition of NaOH. Under similar Si/Al molar ratios, ZSM-5 zeolites with Al pairs contents ranging from 44% to 82% were prepared. In addition, ZSM-5 zeolites were synthesized under different water contents. The lower the water content, the more Al pairs were formed (68% vs. ∼78%). In summary, the state of the Al species is an important factor in determining the content of the Al pairs when preparing ZSM-5 zeolites.

Facile auto-combustion synthesis of calcium aluminate nanoparticles for efficient removal of Ni(II) and As(III) ions from wastewater

ABSTRACT We herein report the synthesis of monoclinic calcium aluminate (CaAl2O4) nanoparticles via a facile auto-combustion method followed by calcination. We performed the auto-combustion method using aluminium nitrate and calcium nitrate as oxidants and different fuels as reductants such as urea, glycine, and a mixture of urea and glycine, with various fuel-to-oxidant equivalence ratios . Then, the combusted samples were calcined at different temperatures; 600 and 800 °C. The products were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, field-emission scanning electron microscope, and high-resolution transmission electron microscope. CaAl2O4 nanoparticles with an average crystallite size of 40.4, 38.8, and 33.7 nm were obtained after calcination at 800 °C using the aforementioned fuels, respectively. TEM images revealed that CaAl2O4 nanoparticles tend to form partially sintered aggregates owing to the high thermal treatment temperature, so they have non-uniform shapes. The produced CaAl2O4 nanoparticles exhibited good absorptivity toward Ni(II) and As(III) ions form aqueous media. The maximum sorption capacities (qm) of CaAl2O4 for the removal of Ni(II) and As(III) were found to be 58.73 and 43.9 mg.g−1, at pH 7 and 5, respectively. The equilibrium isotherms and adsorption kinetics studies revealed that the adsorption data fitted well Freundlich isotherm and pseudo-second-order models, respectively. Besides, the adsorption of Ni(II) and As(III) ions on CaAl2O4 nanoparticles is physisorption. Overall, the obtained results indicated that calcium aluminate nano-adsorbent is a good candidate for the removal of Ni(II) and As(III) ions from wastewater, due to its high efficiency, stability, and re-usability.

In situ growth process and corrosion resistance of a layered double‐hydroxide film on an LA103Z magnesium–lithium alloy

AbstractA layered double‐hydroxide (Mg–Al LDH) film was grown in situ on an LA103Z magnesium alloy in an aluminum nitrate solution at 90°C by adjusting the hydrothermal reaction time. The Mg–Al LDH film comprised Mg–Al LDH and Mg(OH)2, which was obtained after hydrothermal treatment for 24 h, and was thick and dense, with a uniform and compact LDH sheet growing perpendicular to the surface. The LDH sheet showed the best corrosion resistance, and both the Rp and icorr values were two orders of magnitude higher than those of the LA103Z substrate. Nevertheless, the corrosion resistances of the LDH films obtained after treatment for 12 and 30 h were poor owing to the small film thickness and the loose film structure, respectively. Therefore, an appropriate extension of the hydrothermal reaction time can promote the nucleation and growth of LDH and improve the corrosion resistance of the film. When the hydrothermal reaction time exceeded 24 h, the LDH began to dissolve, and the corrosion resistance of the film decreased.

Development and performance analysis of novel in situ Cu–Ni/Al2O3 nanocomposites

Cu–Ni/Al2O3 nanocomposite powders were manufactured using an in situ chemical reaction technique. This technique provides improved wettability and adhesion between the matrix and reinforcement phases. Aluminum nitrate, copper nitrate and nickel nitrate were used as start materials for the production of the composites. The powders were sintered in a hydrogen environment at 900 °C for 2 h after being cold pressed at 700 MPa. To determine the effect of Al2O3 on electrical and thermal conductivities and thermal expansion behaviors, the Cu–Ni matrix was supplemented with 3, 5, and 8 wt% Al2O3. The findings revealed that Al2O3 nanoparticles (20 nm) were dispersed uniformly throughout the copper-nickel matrix. Microhardness was improved from 53.3 HV for Cu–Ni matrix to 92.7 HV for Cu–Ni/8%Al2O3 nanocomposites. The electrical and thermal conductivities and thermal expansion coefficient were reduced as the amount of Al2O3 in the Cu–Ni matrix increased. The electrical conductivity was reduced by 38.7% by addition 5% Al2O3 nanoparticles to Cu–Ni matrix. The high interfacial bonding between Cu–Ni and Al2O3 nanoparticles was the main reason of the hardness improvement and maintaining relatively good electrical and thermal properties.

Structural, magnetic and adsorptive properties of nano spinel of cobalt aluminate doped with nickel for Cr(VI) removal

Nanocrystallines of cobalt aluminate spinel doped with Nickel (MAl2O4; M = Co+2, Ni+2) were synthesized by sol-gel method. The MAl2O4 samples were prepared by using aluminum nitrate; cobalt nitrate, nickel nitrate, citric acid and diethylene glycol mono ethyl ether as precursor materials. The nanocrystallines spinel were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD), Thermal gravimetric (TGA), Scanning electron microcopy (SEM) with the energy dispersive X-ray spectroscopy (EDX) methods. The Specific surface area of the synthesized powders was measured with a Brunauer-Emmet-Teller (BET) apparatus using N2 adsorption. According to obtained XRD patterns the formation of single phase MAl2O4 completed up 800 °C. The average crystallite's sizes spinel and specific surface area at 800 °C were estimated about 11.07 nm and 154 m2 g−1, respectively. The results of SEM analysis show that the nanoparticles shape are as spherical shape, uniform and a little agglomerated. The magnetic behavior of spinels showed the magnetization decreased with increasing nickel ions. Adsorption of Cr(VI) by as prepared spinels were considered. The highest percent of Cr(VI) adsorption was occurred at contact time of 45 min, pH 7.0, and adsorbent dose of 2 g L−1. The order of adsorption capacity of sorbent samples for Cr(VI) removal was as follow: Ni0.5Cu0.5Al2O4 >Ni0.7Cu0.3Al2O4 >Ni0.3Cu0.7Al2O4>NiAl2O4> CoAl2O4. Kinetic studies indicated that the adsorption process follows by pseudo second-order model. Thermodynamic results revealed that the adsorption of Cr(VI) is endothermic, spontaneously process and feasible in the range of 298–338 K.

Supramolecular Assemblies of Sulfonatomethylated Calix[4]resorcinarenes with Aquated Sodium(I), Cesium(I), and Aluminum(III) Ions

AbstractInteractions of C‐iso‐butyl‐calix[4]resorcinarene (1) with sodium sulfite and formaldehyde solution gave a new water‐soluble sulfonatomethylated calix[4]resorcinarene (C4RS) 2 in a quantitative yield. Treatment of 2 with NaOH in a mixture of water, acetonitrile, and methanol afforded complex [Na4(C4RS‐4H)(CH3CN)(H2O)6]2⋅CH3OH (3). Reaction of 2 with NaOH aqueous solution, followed by addition of cesium chloride, led to isolation of complex Cs4Na[(C4RS)2‐5H)](H2O)2 (4). Cation exchange of aluminum nitrate hydrate with complex 3 afforded complex {Al3(H2O)5[(C4RS)2‐9H)]}2⋅(C2H5OH)2⋅(H2O)4 (5). The three new coordination complexes 3–5 were characterized by single crystal X‐ray diffraction analysis. Complexes 3 and 4 display a two‐dimensional bilayer structure through bridging of the sulfonate groups by sodium/cesium cations. The aluminum sulfonatomethylated calix[4]resorcinarene sheets in complex 5 are associated in a one‐dimensional bilayer arrangement and further connected by hydrogen bonds to form a two‐dimensional network.

A simple polyacrylamide gel route for the synthesis of MgAl2O4 nanoparticles with different metal sources as an efficient adsorbent: Neural network algorithm simulation, equilibrium, kinetics and thermodynamic studies

• A polyacrylamide gel method have been used to synthesize the MgAl 2 O 4 nanoparticles. • An artificial neural network model of phase purity of MgAl 2 O 4 was constructed. • The microstructure and adsorption performance of MgAl 2 O 4 nanoparticles were compared. • An adsorption mechanism of MgAl 2 O 4 nanoparticles was proposed. The MgAl 2 O 4 nanoparticles with different particle sizes prepared by a polyacrylamide gel method with different metal salts as raw materials which was used to study its efficiency as an adsorbent for removal of Congo red, acid orange 7 and acid fuchsin from wastewater. It was difficult to obtain pure MgAl 2 O 4 nanoparticles with basic magnesium carbonate or aluminum acetate coupled with other metal salts. Based on the molecular weight, coordination number, ion radius and the number of water of crystallization for the metal salt and the phase purity of the target product, a neural network prediction model was established to predict the effect of synthesis parameters on the phase purity of MgAl 2 O 4 . The microstructure characterization confirmed that the minimum particle size of MgAl 2 O 4 nanoparticles prepared with aluminum nitrate and magnesium sulfate as metal salts was about 22 nm, and the maximum particle size of MgAl 2 O 4 nanoparticles prepared with aluminum nitrate and magnesium chloride as metal salts was about 50 nm. Adsorption experiments of MgAl 2 O 4 nanoparticles were performed as a function of process parameters: various dyes including Congo red, acid orange 7 and acid fuchsin, adsorption time, particles size, initial dye concentration, initial adsorbent concentration, pH value and reaction temperature. The thermodynamic studies showed that the adsorption of MgAl 2 O 4 nanoparticles for removal of Congo red from wastewater is an exothermic and spontaneous process. The maximum adsorption capacity of 89.043 mg/g for the MgAl 2 O 4 nanoparticles was found at 1 g/L of initial adsorbent concentration, 100 mg/L of initial dye concentration, 6.9 of pH, and 299.8 K of temperature for removal of Congo red from wastewater. The adsorption of Congo red, acid orange 7 and acid fuchsin can be assigned to the synergistic effect of electrostatic interaction, pore filling and ion exchange. This present work provides a technical reference for the synthesis of other metal oxide nanoparticles using metal salts with different acid groups.

Investigation of Fe3O4@boehmite NPs as efficient and magnetically recoverable nanocatalyst in the homoselective synthesis of tetrazoles.

Magnetic boehmite nanoparticles (Fe3O4@boehmite NPs) were synthesized from a hybrid of boehmite and Fe3O4 nanoparticles. At first, boehmite nanoparticles (aluminum oxide hydroxide) were prepared via a simple procedure in water using commercially available materials such as sodium hydroxide and aluminum nitrate. Then, these nanoparticles were magnetized using Fe3O4 NPs in a basic solution of FeCl2·4H2O and FeCl3·6H2O. Fe3O4@boehmite NPs have advantages of both boehmite nanoparticles and Fe3O4 magnetic materials. Magnetic boehmite nanoparticles have been characterized by various techniques such as TEM, SEM, EDS, WDX, ICP, FT-IR, Raman, XRD and VSM. SEM and TEM images confirmed that particles size are less than 50 nm in diameter with a cubic orthorhombic structure. Then, Fe3O4@boehmite NPs were applied as a homoselective, highly efficient, cheap, biocompatibility, heterogeneous and magnetically recoverable nanocatalyst in the synthesis of 5-substituted 1H-tetrazole derivatives. Fe3O4@boehmite NPs can be recycled for several runs in the synthesis of tetrazoles. Also, all tetrazoles were isolated in high yields, which reveals high activity of Fe3O4@boehmite NPs in the synthesis of tetrazole derivatives. Fe3O4@boehmite NPs shows a good homoselectivity in synthesis of 5-substituted 1H-tetrazole derivatives.

Structural, optical and electrical properties of undoped and doped (Al, Al + Mn) ZnO nanoparticles synthesised by green combustion method using terminalia catappa seed extract

This paper presents the synthesis of undoped and doped (Al, Al + Mn) ZnO nanoparticles by green combustion method using Terminalia Catappa seed extract as a novel fuel and Zinc nitrate as a precursor, Aluminum nitrate and Magnesium chloride was used as dopant. Synthesized undoped and doped ZnO nanoparticles were characterized by XRD, FESEM, FTIR, UV-visible spectroscopy and impedance spectroscopy. The XRD study of undoped and doped (Al, Al + Mn) ZnO nanoparticles exhibits hexagonal wurtzite structure with high crystallinity. The crystallite size increases from 37.5 nm to 39 nm for Al doping and decreased to 30.5 nm for Al + Mn doped ZnO nanoparticles. Mean grain size of undoped ZnO nanoparticles was found to be 32.5 nm. For Al doped ZnO nanoparticles mean grain size increases (42.9 nm) and then decreases (21.25 nm) for Al + Mn doped ZnO nanoparticles. FTIR studies confirms the formation of Zn-O bond at 462, 455 and 439 cm−1 for both undoped and doped ZnO nanoparticles. The optical band gap was found to be 3.25, 3.2 and 2.54 eV for undoped and doped (Al , Al + Mn) ZnO nanoparticles respectively. The dielectric properties and conductivity studies were carried for undoped and doped (Al, Al + Mn) ZnO nanoparticles at various fixed temperatures (50 to 350 °C) by varying frequency from 10 Hz to 8 MHz. Dielectric constant increases with rise in temperature and, dielectric constant decreases with rise in frequency and remains constant at higher frequency. At lower frequencies AC conductivity was constant and increases as the frequency increases. Grain and grain boundary resistance for the synthesised ZnO nanoparticles were studied by complex impedance analysis and result exhibits a decrease in grain resistance with rise in temperature. The ZnO nanoparticles doped with Al shows improved microstructural properties, decreased optical band gap and activation energy. Hence these nanoparticles are suitable material for sensors and optoelectronics applications.

Green processing of alumina nanomaterial for thermal application

The morphological parameter such as shape, size has a significant contribution to thermal applications in different industries which depends on the method adopted for the synthesis of nanoparticles. The green technique of synthesis of nanoparticles from natural extracts has practical importance for a wide range of nanomaterials. The present work included the synthesis of alumina nanoparticles from aluminium nitrate with a bio-based, low-cost green method. Thermal conductivity of the nanofluids varies from 0.5378 W/mK – 0.7299 W/mK with enhancement of 1.8% − 21.44% for 0.01–0.05 vol% in temperature range 30 °C − 50 °C. With the increase of sonication time, thermal conductivity also increases.

Importance of Dynamic Mechanical Analysis to Predict Performance of the Polyvinyl Acetate Wood Adhesives in Summer Season

Conventionally available Polyvinyl acetate (PVAc) wood glues are polyvinyl alcohol (PVA) stabilized, with drawbacks like poor strength at high humidity, poor strength at high temperature and workability at low-temperature. PVAc is non-resistant to high humidity, and if such adhesive bonds are exploited in a highly humid environment, its strength substantially decreases. Sufficiently water-resistant adhesive bonds are achieved by modifying PVAc dispersion with special chemicals like acrylic acid (AA) and N-methylol acrylamide (NMA) as a co-monomer, Silanes, and ethylene modified PVA. The Lewis acids like aluminium chloride and aluminium nitrate are used as cross-linkers. So PVAc adhesives are classified as reactive and non-reactive glue. Application of non-reactive D1 (as per EN 204-205) and reactive D2 and D3 (as per EN 204-205) adhesives for bonding laminate on plywood is a regular practice in the Indian market. In summer time, Crack formation was seen in laminate bonded with reactive D2 and D3 adhesives in regions where the room temperature was above 45°C. However, if the same laminate substrates were bonded with non-reactive D1, no cracks were seen. To analyse the above phenomenon, we have done Dynamic mechanical analysis of non-reactive D1, reactive D2 and D3 adhesive.

How do layered double hydroxides evolve? First in situ insights into their synthesis processes.

Despite the importance of layered double hydroxides (LDHs) in catalysis, medicine and water treatment, the crystallisation process of these materials is seldom investigated. In this study, in situ characterisation techniques granted unprecedented experimental access to the formation dynamics of carbonate-intercalated Mg2+/Al3+ LDHs as model system when applying the most relevant co-precipitation approaches by exploring the effects of temperature and concentration of reactants. For this purpose, a combinatorial multi-modal characterisation approach was applied involving in situ measurements of pH, ion conductivity and light scattering, as well as synchrotron-based in situ X-ray diffraction (XRD). Shortly after beginning the addition of basic solutions (i.e., sodium carbonate and sodium hydroxide) to the solutions of magnesium nitrate hexahydrate and aluminium nitrate nonahydrate, a stable pH was reached due to the uptake of hydroxyl ions for nuclei formation. Shortly after, crystal growth phase was detected by an increase in the light scattering signal and confirmed via in situ XRD. Increasing the concentration of reactants accelerated the onset of crystal growth by 70% without significantly changing the crystallite size. On the other hand, increasing the temperature up to 65 °C showed a smaller influence on the reaction kinetics but resulted in a two-fold increase in crystallite size. Adding the solution of metal precursors to the basic solution, saturation was rapidly reached, without an induction period, favouring the formation of very small crystallites of approximately 10 nm.