Thermogravimetric Differential Thermal Analysis Research Articles

Titanium Source Choice Affects the Nonhydrolytic Sol‐Gel Synthesis and Morphology of Fe2TiO5

AbstractFe2TiO5 powders are synthesized via nonhydrolytic sol‐gel method, and the effects of titanium sources on the synthesis and morphology of Fe2TiO5 powders are investigated via differential thermal analysis‐thermogravimetric (DTA‐TG), X‐ray diffraction (XRD), Transmission Electron Microscope (TEM), Field Emission‐Scanning Electron Microscope (FE‐SEM) and Fourier Transform Infrared (FT‐IR). It is beneficial for the low‐temperature synthesis of Fe2TiO5 to form Fe−O−Ti bonds when TiCl4 and Ti(OC4H9)4 are used as titanium source. But it is difficult to synthesize pure Fe2TiO5 phase and the powders synthesized are seriously agglomerated, when TiCl4 is used as titanium source. When Ti{OCH(CH3)2}4 is used as the titanium source, Fe2TiO5 phase can not be synthesized until 800 °C, which is due to Fe−O−Ti bond does not form in the xerogels. Fe2TiO5 powders prepared with Ti(OC4H9)4 as titanium source are small in particles size of 100–200 nm with high dispersion and element uniformity.

Layered Double Hydroxide Catalysts Preparation, Characterization and Applications for Process Development: An Environmentally Green Approach

The adage of new generation of fine chemicals process is the best process applied in the absence of conventional methods. However, many methods use different reaction parameters, such as basic and acidic catalysts, for example oxidation, reduction, bromination, water splitting, cyanohydrin, ethoxylation, syngas, aldol condensation, Michael addition, asymmetric ring opening of epoxides, epoxidation, Wittig and Heck reaction, asymmetric ester epoxidation of fatty acids, combustion of methane, NOx reduction, biodiesel synthesis, propylene oxide polymerization. Layered Double Hydroxides (LDHs) have received considerable attention due their potential applications in flame retardant and has excellent medicinal property for reducing acidity. These catalysts are characterized using analytical techniques, such as: X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Raman spectroscopy, Thermogravimetric-Differential Thermal Analyzer (TG-DTA), Scanning electron microscope (SEM), Transmission electron microscopes (TEM), Brunauer-Emmett-Teller (BET) surface area, N2 Adsorption-desorption, Temperature programmed reduction (TPR), X-ray photoelectrons spectroscopy (XPS), which gives its overall picture of its structure, porosity, morphology, thermal stability, reusability, and activity of catalysts. LDHs catalysts have proven to be economic and environmentally friendly. The above discussed applications make these catalysts unique from Green Chemistry point of view since they are reusable, and eco-friendly catalysts. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Nanostructured nickel doped zinc oxide material suitable for magnetic, supercapacitor applications and theoretical investigation

This Paper describes the synthesis of nickel doped ZnO is planned by chemical co-precipitation techniques. The prepared nanostructured nickel doped zinc oxide samples were analyzed by thermogravimetric differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infra red (FTIR), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), electron paramagnetic resonance (EPR), and cyclic voltametry (CV). Nanostructure nickel doped ZnO materials have developed as promising for the basis of its broad range of employing in diverse areas. The attractive properties of nickel doped ZnO materials are highly demanded in high-energy potential applications. The nickel doped zinc oxide materials are hexagonal wurtzite arrangement is confirmed by XRD. The morphological -features of FE-SEM show nickel doped zinc oxide NPs are the structure of spherical type with agglomeration. The calculated particle size 11 nm is confirmed by HR-TEM. EPR spectra of nickel doped zinc oxide nanoparticles are ferromagnetic nature. Further, CV studies of Ni doped ZnO materials of the specific capacitance value is 133 Fg-1 at the scan rate 10 mVs−1 it is suitable for super capacitor application. The quantum chemical calculations were done by using DFT techniques through B3LYP/LANL2DZ level of basis set.

Slow Phase Transition-Induced Scan Rate Dependence of Spin Crossover in a Two-Dimensional Supramolecular Fe(III) Complex

Slow Phase Transition-Induced Scan Rate Dependence of Spin Crossover in a Two-Dimensional Supramolecular Fe(III) Complex

Conjugation of triphenylantimony(V) with carvacrol against human breast cancer cells.

The organoantimony derivative of formula trans-O,O-[Ph3SbV(Carv)2] (TPAC) (CarvH = carvacrol) is obtained by the oxidation of triphenylstibine (Ph3SbIII) with hydrogen peroxide in the presence of carvacrol (CarvH). Physical methods such as X-ray Fluorescence (XRF) spectroscopy, single crystal and powder X-ray diffraction analysis (XRD and PXRD), Attenuated Total Reflection Fourier Transform Infra-red (ATR-FTIR) spectroscopy, Thermogravimetric Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DTG/DSC), confirm the retention of the formula of TPAC throughout the sample mass in solid state, while UV-Vis spectroscopy in the solution. TPAC is the first example of carvacrol (the main ingredient of oregano) covalently bonded to any metal ion. Only the trans-O,O-[Ph3Sb(Carv)2] isomer was isolated suggesting stereo-selectivity of the preparation route. TPAC inhibits in vitro both human breast adenocarcinoma cell lines: MCF-7 (positive to hormones receptor (HR +)), MDA-MB-231 (negative to hormones receptor (HR-)) stronger than normal human fetal lung fibroblast cells (MRC-5). The MCF-7 cells morphology, DNA fragmentation, Acridine Orange/Ethidium Bromide (AO/EB) Staining, cell cycle arrest and mitochondrial membrane permeabilization tests suggest an apoptotic pathway for cell death, especially, through the mitochondrion damage. The binding type of TPAC toward the calf thymus CT-DNA was initially deduced ex vivo from the differentiation of the DNA solution viscosity. Fluorescence spectroscopy confirms the interaction mode suggested. Spectroscopic evidence (FTIR, UV-Vis) suggest that glutathione (GSH) (a tripeptide over-expressed in tumor cells) induces conversion of non-active pentavalent antimony, which is contained in TPAC, to active trivalent one, providing a new strategy for the development of targeted chemotherapeutics.

Chip-Based MEMS Platform for Thermogravimetric/Differential Thermal Analysis (TG/DTA) Joint Characterization of Materials

Combined use of thermal analysis techniques can realize complementarity of different characterization methods. Comprehensive thermal analysis with both thermogravimetric analysis and differential thermal analysis (TG/DTA) can measure not only mass change of a sample but also its temperature change during programmed heating-induced reaction or phase transition processes, thereby obtaining multiaspect thermal information of the material such as dehydration, structural decomposition, phase change and thermal stability. This study proposes and develops a MEMS chip-based TG/DTA microsystem that integrates both programmed heating and detecting elements into a TG chip and a DTA chip to enable the microinstrument performing TG/DTA joint characterization under microscope observation. The TG chip contains a self-heating resonant microcantilever to measure heating-induced mass change of a sample and the DTA chip is with a microheater and a temperature-detecting thermopile integrated on a suspended thermal-insulating diaphragm. Only nanogram and microgram-level samples are needed for the TG and DTA chips, thereby achieving safe measurement to energetic materials such as strong oxidants. The chip-based microinstrument surpasses the state-of-the-art commercial TG/DTA instruments that have, in the long term, suffered from large sample-amount (milligram level) requirements and have been unable to measure energetic materials. Compared with commercial instruments, the chip-based microinstrument is advantageous given its more accurate analysis, much higher heating rate, much smaller instrument volume and much lower power consumption, etc. The microinstrument has been fabricated by using wafer-level MEMS techniques. Testing results show that the mass-detection sensitivity of the TG-chip is as high as 0.45 Hz/pg in air and the temperature sensitivity of the DTA chip achieves 2.9 mV/K under the high heating rate of 25 °C/s. The strong oxidant of KMnO4 is analyzed with the TG/DTA joint characterization under microscopic observation. At the same time as microscope observation of the thermal decomposition phenomena, two-step thermal decomposition process of KMnO4 is identified and the thermal decomposition temperatures are obtained. The TG/DTA microinstrument is promising to be applied for study of various materials.

Synthesis, crystal structure, and optical properties of benzyl isoquinolinium dibromo-bis(isothiocyanate)zinc(II)

The title inorganic-organic hybrid material containing a mixed anion, [BzIQl]2[Zn(NCS)2Br2] (1) (BzIQl = benzyl isoquinolinium, NCS− = isothiocyanate), crystallizes with a benzyl isoquinolinium cation and half of a bis(bromo)-bis(isothiocyanate)zinc(II) anion in the asymmetric unit. It was characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), electrospray ionization mass spectrometry (ESI-MS), and powder and single crystal X-ray diffraction (PXRD and SC-XRD). The organic cation exhibits a Λ-shaped configuration in which two aromatic rings form an inclined dihedral angle of 90.12°. The ZnII ion in the anion is coordinated by two Br ions and two isothiocyanate ions, and two contiguous anions forms a dimer through S···Br interactions. The thermal stability of the hybrid crystal analyzed by thermogravimetric-differential thermal analysis (TG-DTA) reveals that the title crystal was stable up to 170 °C. The PXRD study confirms the phase purity of the crystalline sample. The band gap energy between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) explains the eventual charge transfer interaction that take place mainly between the anion and [BzIQl]+ cation, and the low value (0.46 ev) indicates the suitability of the crystal for optical application. The first hyperpolarizability predicted using density functional theory (DFT) is more than 720 times that of the reference potassium dihydrogen phosphate crystal (KDP).

Effects of Dioctyl Phthalate on Performance of Asphalt Sealant

Dioctyl phthalate (DOP) was introduced into asphalt-based sealant as a plasticizer in this work. Four kinds of sealants with different DOP content were prepared, and thermal stability and low-temperature performance of five samples with asphalt as a control group were evaluated by fluidity test, softening point test, thermogravimetric-differential thermal analysis (TG-DTA), low-temperature tensile test, and differential scanning calorimeter (DSC), respectively. Furthermore, the mechanism of DOP on sealant properties was analyzed by Fourier transform infrared spectroscopy (FTIR) and fluorescence microscope. Results show that DOP can significantly improve the low-temperature performance of sealant, but slightly deteriorate the high-temperature performance. This is because DOP can supplement the light component of sealant and enhance the fluidity of the internal components. On the one hand, DOP reduces the apparent activation energy of sealant and lowers the barrier to chemical reactions, indicating that DOP is slightly detrimental to the thermal stability of sealant. On the other hand, DOP greatly reduces the glass transition temperature of sealant and improves its low-temperature performance. However, there is no evident chemical reaction between DOP and sealant, and physical effects play a major role in the effects of DOP on sealant properties. In addition, DOP can promote the expansion and cross-linking of the polymer in the sealant and ultimately enhance the compatibility between asphalt and polymer molecules. In short, DOP is recommended as a plasticizer to prepare asphalt sealants with excellent properties.

Optimum conditions and application of one-step fluorescent cyanoacrylate fuming method for fingermark development based on PolyCyano UV

Cyanoacrylate fluorescent staining has become a common method for developing latent fingermarks on light-coloured or white objects. The method requires two steps and skilled operation, and the handling process has the risk of damaging the ridge details or even biological samples. To take full advantage of the high-sensitivity fluorescence, recent research efforts on fluorescent cyanoacrylate have aimed to avoid rinsing after staining, add fluorescence to the cyanoacrylate, increase the fluorescence intensity and broaden the fluorescence spectral range. PolyCyano UV is a novel product that can be used to overcome the disadvantages associated with progressing to one-step fuming to directly develop fingermarks. To explore the optimal development conditions and application effects of PolyCyano UV, thermogravimetric differential thermal analysis, fluorescence spectroscopy and control variable analysis are used to determine and analyse the best conditions for using the reagent, including temperature, fluorescence excitation band, relative humidity and fuming concentration. The temperature range of the one-step fuming development method is 212.14 °C–275.16 °C, the wavelength range of the excitation light source is 235–580 nm, the relative humidity is 60%–80%, the concentration of the fume is 1–3 g/m3 and the specific value is related to the surface properties of the object and the aged time of the fingermarks. Additionally, fluorescence spectroscopy shows that the excitation wavelength range of the light source is 235–580 nm. Based on the best fuming condition, many common objects were selected to proceed to the application experiments, which allowed for a comparison with the traditional visualisation method, namely the Cyanobloom reagent + dyeing two-step development method. The comparison showed that latent fingermarks on most non-porous smooth surfaces, especially on light-coloured or white objects, were developed successfully. In addition, a comparative study with the conventional cyanoacrylate glue–fluorescent staining experiments showed that the effect of dyeing afterwards with Rhodamine 6 G is better than the one-step method. The effect of dyeing with BBD is basically the same as that of the one-step method. Key points: One-step fluorescent cyanoacrylate fuming can be a promising alternative for fingermarks developing based on PolyCyano UV in forensic science. The optimum application conditions of PolyCyano UV will provide guidance for fingermark examiners. The one-step fuming method based on PolyCyano UV has many advantages over the secondary dyeing method.

Optimization of polyvinyl alcohol binder on PANI coated pencil graphite electrode in doubled chamber microbial fuel cell for glucose biosensor

In this study, a cost-effective and environmentally friendly polyvinyl alcohol (PVOH) binder was studied by binding Polyaniline (PANI) on pencil graphite (PG) to form a PANI/PG electrode. The physicochemical properties of in-situ chemically synthesized PANI were characterized by ultraviolet-visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric-differential thermal analyzer (TGA-DTA), X-ray diffractometer (XRD), and Scanning electron microscopy-energy dispersive X-ray analyzer (SEM-EDX). The electrochemical properties of PANI coated on PG with different PVOH binder ratios were addressed by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). In addition to power production and wastewater treatment, microbial fuel cells (MFC) are also a promising technology for biosensor applications. This study contributes to the MFC self-powered biosensor activity and its optimizations. For these optimizations, a two-factor, four-level Central Composite design model was performed for the optimization of PVOA binder loading influence on PANI-modified PG anode two-chambered MFC fed by glucose. From the statistically designed model, the two independent factors were developed to correlate them with MFC sensitivity. Thus, for this model, values of R-squared and adjusted R-squared were 0.9916 and 0.9776, respectively, and this demonstrates that the proposed model was significant. The optimum values of maximum glucose-fed MFC sensitivity were observed at a mass of PVOH and initial glucose concentration values of ~15.293 wt% and ~ 0.718 mM, respectively. The result shows the achievement of 4.464 μA mM−1 cm−2 sensitivity, which is significant compared with values of 4.443 μA mM−1 cm−2 of sensitivity obtained after four experimental runs. Their sensitivity difference was found to be 0.021 (2.1%), and the model prediction was adequate to sense glucose in MFC.

Low Temperature H2S Removal by Adsorbent Prepared using Water Treatment Sludge

Water treatment sludge (WTS), hydrothermally synthesized powder (HSP) using the WTS, and CuO added HSP (CuHSP) after heat treatment at 500℃ were prepared and its hydrogen sulfide (H₂S) removal properties were investigated. The physicochemical properties of adsorbents were studied by N₂ adsorption-desorption, scanning electron microscope, x-ray diffraction, and thermogravimetric-differential thermal analysis. The specific surface area for the WTS was 42.7㎡/g and was increased by 78.1㎡/g after the hydrothermal reaction and was maximized by 168.7㎡/g after the heat treatment at 500℃ for 1 h. The breakthrough time of the WTS, HSP, and CuHSP for H₂S removal at 25℃ was measured for 10 min, 20 min, and 170 min, respectively, thus demonstrating an effective application of WTS as the catalytic carrier for low temperature H₂S removal.

Different Plant Sporopollenin Exine Capsules and Their Multifunctional Usage.

Sporopollenin exine capsules (SECs) are highly resistant to heat and various acids and bases. They are also cheap, highly porous, eco-friendly polymer biomaterials with stable microencapsulation capacity. Due to their strong and uniquely shaped exine layers, they can allow growth on metal oxide materials, as a biotemplate for use in different applications. In this study, first, a single SEC extraction method was applied to three different pollens from Pinus, Fraxinus excelsior, and Tilia. Scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and thermogravimetric/differential thermal analysis (TGA/DTA) measurements both before and after the extraction process were performed to observe changes in surface area, morphology, porous structure, and degradation properties. The protein content and removal were analyzed by elemental and spectrophotometric analyses. Then, SECs were loaded by passive and centrifuge loading for drug delivery, and the loading capacities were analyzed by Fourier transform infrared spectroscopy and spectrophotometry. The method was successful in opening the pores and maintaining the structural integrity of SECs. It was determined that the morphology and porosity affected the encapsulation efficiency. According to the loading capacities, Tilia SECs were the most efficient SECs for both loading methods. In addition, three different SECs were hydrothermally coated with cobalt and then heat-treated to obtain a metal oxide structure. A CO3O4 supercapacitor electrode constructed using CO3O4-F. excelsior SEC powder had the best surface area parameters. The electrode showed a maximum specific capacity of 473 F/g for over 3000 continuous cycles of galvanostatic charge–discharge (GCD).

Synthesis, structural characterization, antibacterial activity, DFT computational studies and thermal analysis of two new thiocyanate compounds based on 1-phenylpiperazine

Two hybrid materials, (HPhPip)2[Co(NCS)4] (I) and (HPhPip)(NCS)•PhPip (II), were grown using the slow evaporation method. The characterization of both compounds was accomplished by means of different analytical techniques such as IR, TGA–DTA, and single X-ray diffraction. XRD showed that compounds (I) and (II) crystallized into triclinic and noncentrosymmetric orthorhombic systems, respectively. In Compound (I), the Co(II) ion is surrounded by four NCS−anions and shows a distorted tetrahedral coordination geometry. Crystal packing analysis indicates that the [Co(NCS)4]2−anion and 1-phenylpiperazinium cation are linked together through N–H…S to form a graph set. Compound (II) presents an interesting 3-D network via N–H…N, C–H…S, and C–H•••π intermolecular interactions between HPhPip+, NCS−, and PhPip, consolidating the stacking of the crystal. FT-IR was used to explore the modes of vibration of the different functional groups present in two compounds. A theoretical investigation has also been performed via DFT on the molecular structure of compounds, allowing the determination of the Mulliken charge distribution, the Molecular Electrostatic Potential maps, and the HOMO–LUMO diagrams. The Hirshfeld surface, two-dimensional fingerprint plots and enrichment ratio were investigated to indicate the important role of intermolecular interactions. The robust thermal stability of the two crystals was ensured by thermogravimetric–differential thermal analysis. Finally, the bacterial potency of two compounds has been surveyed.

Growth, spectroscopic and Hirshfeld surface analysis on pyridine urea single crystal

Organic single crystal pyridine urea (PYUA) was synthesized using the slow evaporation solution growth method at room temperature. Structural characteristics of the crystal were studied through crystal X-ray diffraction, Fourier transform infrared (FT-IR), and UV-vis-NIR spectral analyses. The thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques was used to investigate the thermal stability of the PYUA crystal. The Vickers hardness study confirmed the PYUA as a soft crystal constructed by H-bonds and π…π interactions of average strength. The DFT calculations with the B3LYP method and Gaussian 09 software were used to perform computational analyses in a gaseous state. Hirshfeld investigations reveal H-H interactions demonstrating the largest contribution in the molecular packing.

The novel and facile electrolysis method for removing the cobalt binder phase from large diameter polycrystalline diamond compacts

The thermal stability, wear resistance and impact toughness of polycrystalline diamond compact (PDC) are the primary determining variables in determining the performance. The cobalt binder contributes significantly to the PDC's thermal stability and wear resistance. To increase the thermal stability of the PDC, this paper used electrolysis to remove the cobalt binder from the polycrystalline diamond (PCD) layer of the PDC with a diameter of 62 mm. The optimal process parameters for cobalt removal via electrolysis were determined by examining the electrolyte concentration, the electrolytic voltage, and the electrolytic time. The cobalt removal impact was evaluated using a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), an X-ray diffraction (XRD), and thermogravimetric analysis-differential thermal analysis (TG-DTA). In addition, the abrasion ratio of the PDC samples were tested. The experimental results indicated that the optimal electrolysis parameters for cobalt removal were obtained when the concentration of cobalt sulphate was 4 g/100 mL, the electrolysis voltage was 2.5 V, and the electrolysis time was 10 h; in this case, the cobalt removal rate from the PCD layer exceeded 80%, and the cobalt removal depth was 372 μm. TG-DTA analysis revealed that the thermal stability of PDC was significantly enhanced as a result of the initial graphitization temperature of the cobalt removal sample being increased from 1071 °C to 1113 °C, but the abrasion ratio rose by more than 20%. It was discovered that electrolysis may efficiently remove the cobalt binder phase from the PCD layer, therefore improving the thermal stability and wear resistance of PDC.

Layered ammonium vanadate nanobelt as efficient adsorbents for removal of Sr2+ and Cs+ from contaminated water

In this study, a layered ammonium vanadate (NH4V4O10) nanobelt adsorbent was synthesized by a facile hydrothermal method to remove Sr2+ and Cs+ from contaminated water. The NH4V4O10 nanobelt was texturally and morphologically characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman, thermogravimetric differential thermal analyzer (TG-DSC), Brunauer– Emmett–Teller (BET), and X-ray photoelectron spectroscopy (XPS) both before and after adsorbing Sr2+ and Cs+. The results showed that the NH4V4O10 nanobelt exhibited the optimal morphological structure with a 2:1 ratio of NH4VO3:dipropylamine. In the lattice of the adsorbent, the horizontal distance between oxygen atoms was 0.55 nm, the vertical distance between vanadium was 0.35 nm, and the layer distance of the adsorbent was 0.931 nm. The structure characterization indicated the VO6 octahedron formed a basic framework through sharing connected vertices. Adsorption mechanism studies indicated that ion exchange was the main adsorption mechanism for removing Sr2+ and Cs+. Batch experiments revealed that the adsorption capacity for Sr2+ was 192.52 mg/g under a pH of 2. Similarly, the adsorption capacity for Cs+ was 251.09 mg/g when the pH was 5. The adsorption kinetics and adsorption isotherms data were in accordance with the pseudo-second-order kinetic model and Langmuir model, respectively. Adsorption isotherms results also indicated that the adsorption of Sr2+ and Cs+ was endothermic (ΔHSr0 = 3.6 kJ/mol, ΔHCs0 = 29.1 kJ/mol) and increased entropy (ΔSSr0 = 29.15 J/molK, ΔSCs0 = 160.38 J/molK). Finally, the structure of the adsorbent, the adsorption performance and mechanism, and the interpretation of selective adsorption were also calculated by DFT method at the molecular level and the results were consistent with the experimental data.

Hydrophobic coatings prepared using various dipodal silane-functionalized polymer precursors

This study introduces synthetic methodology to develop hydrophobic surfaces. Hydrophobic surfaces are fabricated via cross-linking of inorganic-organic hybrids, prepared from dipodal alkoxysilane-functionalized urethane precursors (AFUS). The inorganic-organic (I-O) hybrids are synthesized by co-hydrolysis and co-condensation of various precursors. The hybrid solutions are then used to fabricate hydrophobic coatings through spin coating method. The coatings exhibited water contact angle greater than 90°. The properties of the hydrophobic coatings are analysed and characterized using scanning electron microscopy (SEM) and contact angle measurement (CA). The precursors are characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric-differential thermal analysis (TG-DTA) and gel permeation chromatography (GPC). These environment-friendly inorganic-organic hybrid coatings have shown great potential in replacing the toxic fluorinated alkylsilane based coatings.

Influence of hydrothermal synthesis conditions and carbonation on physical properties of xonotlite-based lightweight material

This paper investigates the effect of the hydrothermal synthesis conditions on the formation of xonotlite and the change of xonotlite-based lightweight material’s (Xo_AAC) physical properties under carbonation. Experiments included: quantitative X-ray diffraction, scanning electron microscopy, thermogravimetric differential thermal analysis, drying shrinkage, carbonation shrinkage, compressive strength, mercury intrusion porosimetry, thermomechanical analysis, solid-state nuclear magnetic resonance, water vapor absorption isothermal, and nanoindentation test. The pure crystalline xonotlite was formed at 230 °C for the autoclaving time of more than 18 h and at short heating time (2 h). The drying shrinkage and dimensional change rate of Xo_AAC were smaller than that of autoclaved aerated concrete (AAC). The compressive strength of Xo_AAC was slightly increased after carbonation. The carbonation of Xo_AAC occurred more quickly than AAC containing silicone oil. However, the amount of carbonation shrinkage was almost the same for both Xo_AAC and AAC in a later period.

Synthesis, Characterization and Application of Chitosan-TPP-ZnO Nanocomposite for Efficient Treatment of Effluent Containing Sulphur Dye

In this present study, an attempt has been made to synthesize Chitosan-TPP (sodium tripolyphosphate)-ZnO (CT/ZnO) nanocomposite for wastewater treatment to enhance the degradation of dyes and harmful compounds in effluent water. CT/ZnO nanocomposite was synthesized by a very facile method of chemical precipitation at room temperature. The structural, morphological, optical, elemental and thermal properties of CT/ZnO nanocomposite were studied using X-ray Diffraction (XRD), High-Resolution Scanning Electron Microscopy (HRSEM), UV–visible-Diffuse Reflectance Spectroscopy (UV–vis-DRS), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA) and Differential Scanning Calorimetry (DSC). XRD analysis showed the crystalline nature of CT/ZnO nanocomposite and confirmed the crystal structure as hexagonal primitive. The average crystallite size calculated using Debye Scherrer’s formula was found to be 42 nm. HRSEM images revealed the agglomeration of nanoparticles which resulted in increased particle size. Energy Dispersive X-ray Spectroscopy (EDAX) performed along with HRSEM confirmed the purity of CT/ZnO nanocomposite. UV–vis-DRS analysis displayed peaks corresponding to chitosan and ZnO nanoparticles in the UV region, which suggests that ZnO nanoparticles had dispersed well into the chitosan nanoparticle system. This nanocomposite could be used effectively in UV screening. FTIR and XPS results exhibited enhanced interaction between the amine groups of chitosan and the metal oxide ZnO in the nanocomposite. The three-step mass reduction was observed in the TGA thermogram of the sample which was in good agreement with DTA and DSC thermograms and displayed good thermal stability at ambient conditions. CT/ZnO nanocomposite showed efficient decolourization of effluent water due to the combined effect of the adsorption, photocatalysis and coagulation.

Synthesis and characterization of chitosan encapsulated nickel oxide nanoparticles modified with folic acid

This research work was aimed to investigate the physicochemical properties of Chitosan (CS) encapsulated Nickel oxide (NiO) nanoparticles modified with folic acid (FA), fabricated by a simple solvothermal method. Characterization of the nanoparticles was carried out using the X-ray diffraction analytical technique. Functional groups were identified by Fourier transform infrared spectroscopy (FTIR). UV–Visible (UV) and Thermogravimetric/differential thermal analyses (TG/DTA) were used to study the optical and thermally decomposed nature of the final products. The crystallite size of the final products using the Debye-Scherrer formula is estimated to be 20.71 nm and 22.29 nm respectively. Tauc’s relation has been utilized to estimate the bandgap energy (Eg) of the nanoparticles. A scanning electron microscope (SEM) study was conducted to record the surface structure of the nanoparticles. The observed zeta potential value of CS-NiO nanoparticles is −20.1 ± 4.12 mV and −16.6 ± 4.18 mV for FA-CS-NiO nanoparticles respectively. Hence, the findings of synthesized nanoparticles could be prioritized to examine the biological effects in future studies.