Differential Scanning Calorimetry/thermal Gravimetric Analysis Research Articles

Evidence of Surface Properties by Isopropanol Decomposition Reaction and NH3‐TPD over Ni−Fe Spinel Nanoparticles Prepared via Hydrothermal Route

AbstractIn this work, surface properties evaluated by catalytic conversion of isopropanol and by ammonia Temperature Programmed Reduction (NH3‐TPD) over ferrite spinel nanoparticles was investigated. Bulk NiFe2O4 with specific surface area 114 m2/g and crystallites size 6 nm was prepared by hydrothermal synthesis using nitrates as precursors. X‐ray diffraction (XRD), Raman spectroscopy, specific surface area by B.E.T, Scanning Electron Microscopy (SEM) and X‐ray energy dispersive microanalysis (EDS), Transmission Electron Microscopy (TEM) and X‐ray Photoelectron Spectroscopy (XPS) techniques were used for their structural and textural characterizations. The reducibility by hydrogen at variable temperatures was investigated by Temperature Programmed reduction (H2‐TPR) and Thermal Gravimetric Analysis‐ Differential Scanning Calorimetry (TGA‐DSC). The total acidity and acid strength distribution was determined by NH3‐TPD. The synthesized oxide showed the presence of mixed phases containing the inverse spinel structure NiFe2O4 as the major phase and iron oxide α‐Fe2O3 as an additional phase. It was shown that the surface of the powder was richer in Ni2+ species. The surface acidity (Brönsted and Lewis) determined by NH3‐TPD showed that the number of acidic sites increased dramatically with the temperature. The catalytic conversion of isopropanol yields both acidic and redox/basic sites were available. A good correlation between textural, structural, redox and acid‐base properties of catalyst is established.

Conductivity Study on Proton-Conducting Nanocomposite Plasticized Polymer Electrolytes: A Review

Abstract:This paper reviews proton-conducting polymer electrolytes comprising different polymers, salts, and acids. The ionic conductivity of plasticized polymer electrolytes has been found to increase with the addition of plasticizers due to the dissociation of ion aggregates or undissociated salt/acid present in the electrolytes, i.e., σ (plasticized polymer electrolytes) > σ (unplasticized polymer electrolytes). Proton-conducting nonaqueous nanocomposite plasticized polymer electrolytes containing poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), polymethylmethacrylate (PMMA), polyethylene oxide (PEO) polymers; different ammonium salts and acids as proton conductors; ethylene carbonate (EC), propylene carbonate (PC), dimethylformamide (DMF), dimethylacetamide (DMA), dimethyl carbonate (DMC), diethyl carbonate (DEC) as plasticizers; fumed silica and alumina as nano-fillers have been discussed in details. Conductivity studies (effect of salt/acid, effect of plasticizers, effect of nano-fillers, and effect of temperature), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA) studies for these electrolytes have been discussed and reported in the paper. Nanocomposite plasticized polymer electrolytes showed high ionic conductivity (in the order of 10-1 to 10-2 S/cm) at room temperature along with good thermal and mechanical stability due to the simultaneous addition of both plasticizers and nano-fillers. These nanocomposite polymer electrolytes are the best candidates for use in various electrochemical devices like solid-state batteries, fuel cells, supercapacitors, sensors, separators, and other electrochromic devices.

The effect of vitamin C in the formulation of pectin/thiolated alginate buccal adhesive patches: In vitro and Ex vivo evaluation

The present study outlines the prospect of a pectin (Pec)/modified alginate (Alg) buccal patch as drug delivery device in the localized treatment of oral cavity diseases. Firstly, Alg was modified with acrylic acid, and thiolated with cystein to enhance its mucoadhesive properties. Then modified Alg was characterized with Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. As a proof of concept, Pec/modified Alg buccal patches were formed via the conventional solvent casting technique. Then the patches were characterized by FTIR and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). Vitamin C (Vit C) was used for in vitro drug release assay, and the release amount was 2.10 mg/g polymer in simulated salivary pH 6.8. Ex vivo mucoadhesion assays of Vit C loaded Pec/modified Alg patch did not have a negative effect on the mucoadhesion feature of the material. The cytotoxicity study indicated that Pec/modified Alg buccal patches did not exhibit apparent cytotoxicity against NIH/3T3 cell lines. Notably, it was found that Vit C in the patch formulation has an accelerating effect on wound healing. According to all results, Vit C loaded Pec/modified Alg buccal patch might be a promising candidate for localized buccal drug release systems.

Comparison of tribological behaviors of polycrystalline diamonds synthesized by titanium- and boron-coated diamond particles

In this study, the influence of the coating of diamond particles on the tribological behaviors of polycrystalline diamond (PCD) was investigated. Titanium- (Ti)- and Boron- (B)-coated diamond particles were sintered under high pressure-high temperature condition to obtain Ti-PCD and B-PCD, respectively. The Ti and B coatings were deposited via magnetic sputtering. The PCD specimens were characterized through scanning electron microscopy, X-ray diffraction, impact tests, thermal gravimetric analysis-differential scanning calorimetry and tribological tests. The results indicate that uniform titanium carbide (TiC) and boron carbide (B4C) phases are generated during the sintering processes of Ti-PCD and B-PCD, respectively. The as-obtained TiC phase promotes the tribological behaviors of Ti-PCD in vacuum, including a considerable enhancement of wear resistance. The TiC phase inhibits diamond exfoliation by strengthening interface bonding, which involved transforming the mechanical interaction between the diamond grains and cobalt binder to chemical bonding. However, massive pores are formed during sintering that weakens the interface bonding in B-PCD, and thus the induced wear resistance is low. Therefore, the Ti coating of diamond particles promotes the tribological behaviors of PCD, whereas B coating deteriorates it. This study lays a foundation for the development of suitable technology for the fabrication of PCD.

Hydration investigation of negative temperature concrete at early age based on low-field nuclear magnetic resonance

Few control indexes and detection methods have considered the microstructure properties of negative temperature concrete. As such, construction-focused quality control of negative temperature concrete is still a problem that needs to be solved. In this paper, low-field nuclear magnetic resonance (LF-NMR) was used to monitor the in-situ distribution and dynamical variation of liquid water content in cement paste at both thawed (20 °C) and frozen (−15 °C) states. Results showed that LF-NMR could determine the optimal antifreeze dosage and pre-curing time. LF-NMR was also able to evaluate the properties of negative temperature concrete at early stages, and these properties coincided with the results of compressive strength test. Both LF-NMR and differential scanning calorimetry thermal gravimetric analysis (DSC-TGA) revealed that the main positive effect of the antifreeze on negative temperature concrete is the alleviation of frost heave stress, and not the promotion of hydration. Additionally, a theoretical hypothesis was proposed to explain the reason why concrete with low water/binder ratio is more sensitive to freezing damage at the early stages.

Effects of Boehmite on the Calcination Shrinkage and Mechanical Properties of Gypsum‐Bonded Molds

Calcination shrinkage is an essential factor in the evaluation of a gypsum‐bonded mold. Typically, if traditional fillers are used in a gypsum‐bonded mold, it is difficult to maintain sufficient strength due to the high dosages of fillers. Herein, a new filler system of gypsum, boehmite, is proposed to more efficiently compensate for shrinkage, while minimizing the impact on the strength. The effects of the fillers on the calcination shrinkages and mechanical properties of the gypsum‐bonded molds are studied. The phase transition and thermal expansion behaviors of the gypsum‐bonded molds are tested by thermal gravimetric analysis/differential scanning calorimetry (TG/DSC) and a thermal dilatometer. The microstructures of the fillers and gypsum‐bonded molds are characterized by a scanning electron microscope (SEM). The results show that the dosage of boehmite for near‐zero shrinkage is reduced to about 35 wt%, with the bending strength of the gypsum‐bonded mold remaining above 2 MPa throughout the whole calcination process. The mechanism of calcination expansion is revealed and ultimately attributed to the splitting of boehmite particles. This research provides a novel gypsum‐bonded mold for required high dimensional and mechanical properties, elevating the ability to form complex structures.

Thermal hazard and decomposition kinetics of 1-butyl-2,3-dimethylimidazolium nitrate via TGA/DSC and FTIR

1-Butyl-2,3-dimethylimidazolium nitrate ([Bmmim][NO3]), a kind of versatile and novel ionic liquids, is widely applied in the modern petrochemical industry. Nevertheless, its thermal hazard safety data at high temperature or thermal disturbance conditions are currently unavailable. Therefore, this study aimed to characterize the thermal risk of [Bmmim][NO3] through auto-ignition temperature measurements, flash point analysis, thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC), TGA-Fourier transform infrared spectroscopy (TGA-FTIR) and thermal decomposition kinetics analysis. Additionally, [Bmmim][NO3] was examined using isothermal thermogravimetric analysis at different temperatures (220, 230, 240, 250, 260 and 270 °C). The experimental results show that the flash point of [Bmmim][NO3] is 305.70 ± 9.30 °C and the auto-ignition temperature is 341.00 ± 21.60 °C with an ignition delay time of 8.6 s. In addition, using the nitrogen atmosphere TGA data to calculate the activation energy according to the Friedman, Kissinger and Flynn-Wall-Ozawa methods, roughly the same results were obtained. Finally, TGA-FTIR results show that [Bmmim][NO3] produced acetylene, butane, butanol and carbon dioxide during the thermal decomposition process. This study could provide data support and some guidance for the thermal hazard assessment and safety control of [Bmmim][NO3] during its use and storage.

Effect of Al2O3 on electrical properties of polymer electrolyte for electrochemical device application

Polyvinylideneflouride (PVDF) based nanocomposite polymer electrolyte (NCPE) thin films consist of magnesium nitrate as ionic salt and aluminium oxide nanoparticles as nano-filler has been synthesized by solution casting technique. The electrical, structural, thermal, transport and discharge properties of synthesized films were characterized by Impedance Spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Differential Scanning Calorimetry-Thermal Gravimetric Analysis (DSC-TGA) and Wagner’s DC polarization technique respectively. Complexation was done in polymer electrolyte films were confirmed by XRD and FTIR studies. Composition dependant conductivity studies of films give highest conductivity value for composition: 70PVDF:30 Mg(NO3)2: 2Al2O3 i.e. σ ~ 1.01 × 10−4 S/cm. Thermal stability of polymer electrolyte was confirmed by DSC-TGA. Transport number (tion ~ 1) has been calculated from polarization technique. A test cell fabricated for OCC of NCPE in cell configuration Mg| NCPE| C cell and various parameters have been calculated.

Effect of Immobilization Methods on the Production of Polyethylene-cellulose Biocomposites via Ethylene Polymerization with Metallocene/MAO Catalyst

Polyethylene-cellulose biocomposites were synthesized here via the ethylene polymerization with metallocene as a catalyst along with methylaluminoxane (MAO) as a cocatalyst. The immobilization method in which the catalyst or cocatalyst is fixed onto the catalytic filler (cellulose) can be classified into 3 methods according to the active components fixed onto the filler surface: 1) only metallocene catalyst (Cellulose/Zr), 2) only MAO cocatalyst (Cellulose/MAO) and 3) mixture of metallocene and MAO (Cellulose/(Zr+MAO)). It was found that the different immobilization methods or different fillers altered the properties of the obtained composites and also the catalytic activity of the polymerization systems. It was found that Cellulose/MAO provided the highest catalytic activity among all fillers due to a crown-alumoxane complex, which caused the heterogeneous system with this filler behaved similarly to the homogeneous system. The different fillers also produced the biocomposites with some different properties such as crystallinity which Cellulose/Zr provided the highest crystallinity compared with other fillers as observed by a thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC). Nevertheless, the main crystal structure indicated to the typical polyethylene was still observed for all obtained biocomposites with different fillers as observed by an X-ray diffractometer (XRD). 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).

Utilization of discarded foundry sand (DFS) and inorganic waste from cellulose and paper industry for the manufacture of glass-ceramic materials

Abstract Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials.

Hypervalent organoiodine(v) metal-organic frameworks: syntheses, thermal studies and stoichiometric oxidants.

Iodinated analogues of the highly porous IRMOF-9 and UiO-67 frameworks were prepared and post-synthetically oxidised with dimethyldioxirane (DMDO). Analysis by X-ray photoelectron spectroscopy (XPS) confirmed promotion to the iodine(v) state and detailed differential scanning calorimetry-thermal gravimetric analysis (DSC-TGA) showed the hypervalent metal-organic frameworks (MOFs) undergo exothermic elimination at ∼200 °C with XPS showing hypervalency is maintained. The hypervalent MOFs are active heterogeneous reagents in sulfoxidation and alcohol oxidation reactions. The crystallinity and porosity of the MOFs were maintained following post-synthetic oxidation, thermolysis and after the heterogeneous reactions, as shown by powder X-ray diffraction (PXRD) and gas adsorption analyses. This work showcases the unique ability MOFs hold for studying chemical reactions and the potential for hypervalent organoiodine MOFs as reuseable oxidants.

ELECTRICAL CHARACTERIZATION OF METAL JUNCTION FORMED WITH PURE AND POLYANILINE-BLENDED POLY(SCHIFF BASE) POLYMER

In this paper, we demonstrate the formation of Schottky contact formed by Al with a new class of synthesized conjugated pure poly(Schiff base) (PSB) and its blend with varied concentrations of polyaniline (PANI). The Schottky behavior was transformed into Ohmic in the blended polymer. PSB was synthesized from the solution of polycondensation of terephthaloyl chloride (T) and 4-(4-hydroxybenzylideneamino)phenol (SB). The polymer showed good thermal stability with [Formula: see text] of 312∘C as determined by thermal gravimetric analysis–differential scanning calorimetry TGA–DSC and high molecular weight [Formula: see text] (g/mol) with coiled conformation as determined by laser light scattering. PBS was blended with various weight percentage ratios of PANI (0, 3, 6, 9, 12, 15 percent by weight of the pristine polymer). The metal contact (Au) was formed and studied in the temperature range of 293–373[Formula: see text]K, which showed that Schottky behavior in the intrinsic polymer with an ideality factor was close to 2 and then reduced to 1.0–1.2 in the blended polymers. In blended polymers, the conduction across the junction was characterized by Schottky emission at low field and Poole–Frenkel emission at high field. The Schottky barrier height showed a small increase with temperature, which was attributed to reduction in the built up of image charge. The Schottky and Poole–Frenkel emission coefficients were also determined and Schottky emission coefficient agreed with the theoretical value, while Poole–Frenkel emission coefficient was small. In short, the metal–semiconductor junction was affected by the blending, while conduction within the polymer remained independent of PANI concentration.

Interfacial reaction during co‐sintering of lithium manganese nickel oxide and lithium aluminum germanium phosphate

AbstractUnderstanding interface evolution during co‐sintering of solid Li‐ion conducting electrolytes and Li‐metal oxide cathodes is crucial to development of solid state batteries. In this work, X‐ray photoelectron spectroscopy, X‐ray diffraction (XRD), and thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC) document changes at the lithium manganese nickel oxide (LMNO)/lithium aluminum germanium phosphate interface during sintering. Measurements are performed as a function of sintering gas environment (air vs N2). Upon sintering, manganese is reduced from +4 to a mixture of +4, +3, and +2, while nickel is oxidized from +2 to a mixture of +2 and +3. The Mn2+ species does not arise when LMNO is sintered alone. XRD identifies formation of new chemical phases, LiGe0.5M0.5PO4 (where M = Mn3+ or Ni3+), AlPO4, and NiMn2O4, also not observed when LMNO is sintered alone. The emergence of resistive interfacial phases may offset the increase in conductivity expected when Mn3+ is formed.

Kinetic analysis on nickel laterite ore calcination using model-free and model-fitting methods

Calcination and partial reduction at temperatures below 1000 °C is a primary step in pyrometallurgical extraction of nickel from laterites. Identifying the main reactions that occur during this process and investigating their kinetics provide valuable information on the rates of the reactions and their degree of completion. The main reactions were identified using thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC), X-ray diffraction, and scanning electron microscope energy dispersive spectroscopy (SEM-EDS) tests. Transformation of goethite to hematite, dissociation of lizardite to forsterite and silica, and decomposition of silicate were identified as the main reactions. The kinetic parameters for the three main reactions were obtained using both model-free and model-fitting methods. Comparing the activation energy obtained by the two kinetic approaches, Avrami-Erofeev model was selected as the kinetic model for the aforementioned reactions.

Synthesis and characterization of SiO2 doped Fe2O3 nanoparticles: Photocatalytic and antimicrobial activity evaluation

Silica doped iron oxide (SiO2 doped Fe2O3) nanoparticles (NPs) were successfully synthesized by co-precipitation method at 70 °C using different solvents (acetonitrile, n-hexane and isoamyl alcohol). The synthesized NPs were characterized by FT-IR, X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC) and dynamic light scattering (DLS) techniques. The size of SiO2 doped Fe2O3 NPs was in the range of 5.89 nm–19.89 nm and ellipsoidal morphology with tendency of aggregate formation due to dipole-dipole interactions. The solvents showed variable effect on physico-chemical properties of the NPs. As-synthesized NPs were also evaluated for the antimicrobial activity against set of bacterial and fungal strains i.e., Candida parapsilosis, Aspergilus niger, Bacillus subtilis and Escherichia coli. It was observed that solvents also affected the NPs antimicrobial activity. The SiO2 doped Fe2O3 NPs prepared in acetonitrile showed highest antibacterial as well as antifungal activity. The MIC values were recorded to be 0.31 mg/L and 0.21 mg/L (acetonitrile) and 0.24 mg/L and 0.18 mg/L (isoamyl alcohol) for C. parapsilosis and A. niger, respectively. NPs prepared in n-hexane showed the MIC value of 0.09 mg/L. The photocaalytic activity (PCA) was evaluated by degrading Rhodamine B (RhB) dye. The RhB degradation was 83% for Fe2O3 NPs, which was enhanced considerably in case of doping, solvents also showed variable effect on the PCA for RhB dye degradation. Results revealed that the SiO2 doped Fe2O3 NPs are efficient antimicrobial agent as well as highly active photocatalysts and could possibly be used for the degradation of dyes in textile wastewater.

Production of silver nanoparticles by green synthesis using artichoke (Cynara scolymus L.) aqueous extract and measurement of their electrical conductivity

This work reports the production of silver nanoparticles (AgNPs) by a green method using, for the first time, an extract of artichoke (Cynara scolymus L.), and we explore their electrical properties with the aim of using, for the first time, totally green AgNPs on the preparation of highly conductive inks. The ultraviolet-visible spectroscopy (UV–Vis) studies monitored the surface plasmon resonance phenomenon of green-synthesized silver nanoparticles. Biomolecules of Cynara scolymus L. (CS) extract flower were suggested to be responsible for reducing and capping of AgNPs, by Fourier transformed infrared spectroscopy (FTIR) measurements. Elemental analysis was determined by energy dispersive spectroscopy (EDS). Transmission electron microscopy analysis showed nearly spherical silver nanoparticles surrounded and connected by CS extract material with size varying from 30–80 nm. Scanning electron microscope studies revealed films of AgNPs surrounded by CS extract with nearly spherical and uniformly dispersed silver nanoparticles. The peaks in x-ray diffraction pattern are in good match with that of face-centred-cubic form of metallic silver. The purity and thermal stability of the formed AgNP was detected by differential scanning calorimetry-thermal gravimetric analysis, the melting point at through this analysis was closely related to bulk metallic silver which indicates its purity. Moreover, the electrical resistivity test, the four probe method, confirmed that the green synthesized AgNP using artichoke flower extract had highly electrical conductivity: the resistivity of AgNP films was of c.a. after sintering treatment at for 30 min, which was about three times that of bulk silver . Hence, green synthesis can be a prospective way to develop metallic nanoparticles for the preparation of highly conductive inks with low sintering temperature.

Efficient photodegradation of methylene blue (MB) under solar radiation by ZrC nanoparticles

Due to increase in water pollution, there is a need to dwindle this problem for a clean and green future. Photocatalysts like ZnO, CaO and TiO2 have proved to be triumphant in removal of environmental contaminants. In this present work, ZrC nanopowder has been synthesized using a single-step reduction technique by heating zirconium oxide (ZrO2) and hexane (C6H14) in metallic Mg powder and is used as a photocatalyst for the degradation of methylene blue (MB) dye under solar radiation. Optimization of synthesis parameters (temperature, holding time and carbon content) has been done to obtain single phase ZrC. Various characterization techniques like X-ray diffraction (XRD), transmission electron microscope (TEM), differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA) and X-ray photoelectron spectroscopy (XPS) were studied for various structural, thermal and surface characteristics of as-synthesized samples. The effect of synthesis parameters on crystal distortion of ZrC particles was studied with the help of Double Voigt analysis. Further, the comparative catalytic activity as photodegradation of MB dye with the help of optimized sample was studied under UV and solar radiations. As an effect of illumination source with the same concentration of catalyst and dye, 80% degradation was observed under solar radiations which is quite higher than that observed under UV in 5 h.

Combustion Behavior of High Energy Density Borane–Aluminum Nanoparticles in Hypergolic Ionic Liquids

Incorporating high energy nanoparticulate additives is considered as a means to enhance the performance of hypergolic ionic liquid (IL) propellants. In this manuscript, we demonstrate the energy content of borane–aluminum nanoparticles produced by ball milling and examine the ignition and combustion behavior of hypergolic ILs loaded with up to 30 weight percent (wt %) of the particles, as measured by two different methods. The goal is to better understand the effects of particle loading on hypergolic ignition and combustion mechanism. Bomb calorimetry and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA) combined with X-ray diffraction (XRD) were used to determine the combustible energy content of particles with different capping layers and to examine the nature of the combustion products. Particles were found to have up to 97% of combustible metal content. Rapid scan-Fourier transform infrared spectroscopy (RS-FTIR) and photographic methods were used to examine ignition delay and t...

Structural Evolution of Gossypium hirsutum Fibers Grown under Greenhouse and Hydroponic Conditions

Cotton is the leading fiber source in the textile industry and one of the world’s most important crops. Despite its economic interest, cotton culture exerts an enormous pressure on natural resources (land and water) and has a negative impact on the environment (abuse of pesticides). Thus, alternative cotton growing methods are urged to be implemented. Recently, we have demonstrated that Gossypium hirsutum (“Upland” cotton) can be grown in a greenhouse (controlled conditions) and hydroponically. Here we report on the elucidation of the structural changes of the Gossypium hirsutum fibers during maturation grown [10, 14, 17, 20, 36 and 51 days post anthesis (dpa)] under a greenhouse and hydroponically, by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR ATR) and thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC). The transition from primary to secondary cell wall growth occurs between 17 and 20 dpa—similarly to the soil-based cultures. However, this new cotton culture offers an advantageous pesticide and soil-free all year-round closed system with efficient water use yielding standardized mature fibers with improved properties (maturity, strength, length, whiteness).

Transforming electric arc furnace waste into value added building products

Electric Arc Furnace dust is an abundant hazardous by-product of EAF steelmaking which poses significant environmental challenges for disposal given the presence of high concentrations of heavy metals which can leach into groundwater or contaminate soil when landfilled. This study proposes a novel new process to safely transform electric arc furnace dust into value-added building materials by combining it with blue shale to produce high strength lightweight aggregates. Both materials were characterised elementally and thermally by X-ray fluorescence and differential scanning calorimetry-thermal gravimetric analysis. Dilaotmeter study proved that addition of electric arc furnace dust to blue shale resulted into lower softening temperatures and addition of 5 wt% of electric arc furnace was found to be appropriate as 10 wt% addition showed no bloating behaviour. Light weight aggregates with 0 and 5 wt% electric arc furnace dust were sintered to different temperatures for different holding times. The results revealed that increased sintering temperature and holding time resulted in more porous structure in light weight aggregates with electric arc furnace dust, compared to the samples without electric arc furnace dust. This was observed closely via scanning electron microscope images. The study concluded that the sintering of blue shale with 5 wt% electric arc furnace dust at 1150 °C for 5 min Produced the highest compressive strength (8.25 MPa) with a moderately low density (1.76 g/cm3). The resulting light weight aggregate showed negligible leaching of heavy metals when tested, due to their stabilisation in the crystalline ceramic phase during high temperature sintering. Electric arc furnace dust was confirmed as a potentially valuable input in the production of non-toxic, high performance building materials.