Thermogravimetric Analysis Curves Research Articles

Elaeis guineensisleaves for potential renewable sub‐bituminous coal: Optimization of biochar yield by response surface methodology and product characterization

AbstractPyrolysis of oil palm biomass residue can convert the rich organic matter in biomass into sustainable green energy, thereby addressing the challenge of surplus oil palm biomass residue generated during cultivation. Nonetheless, the pyrolysis of oil palm leaves (OPLs) has received limited attention. In this study, design of experiment‐response surface methodology (DoE‐RSM) was employed to identify the optimal combination of reaction temperature, residence duration, and nitrogen (N₂) flow rate for maximum biochar yield. The elemental analysis, high heating value (HHV), functional group, morphology, pore structure, and thermal behavior were assessed. By varying the operational parameters using response surface methodology, the biochar yield increased by 32.6–85.3%. TheDoE‐RSMpredicted a theoretical yield of 52.1% at 344 °C, 146 min, and 3.2 scfh N₂ flow rate. The experiment confirmed a comparable yield of 53.7% at the stated parameters. TheHHVof 24.14 MJ kg−1was recorded under optimal conditions, and was comparable to sub‐bituminous and bituminous coal. Fourier transform infrared analysis validated theOPLbiochar by weakeningO‐H, C=O,C‐OH, andC‐Hpeaks. Scanning electron microscopy images revealed enlarged pores and altered morphology in theOPLbiochar. X‐ray diffraction showed lower crystallinity of theOPLbiochar than the feedstock. Raman spectroscopy showed higherID/IG, indicating a more disordered carbon structure in theOPLbiochar. Thermogravimetric analysis confirmed higher temperature for main devolatilization ofOPLbiochar, and the differential thermogravimetric analysis curve pattern resembled that of Mukah Balingan coal. The findings are helpful for an initiative to convert a large amount of leftoverOPLsproduced during cultivation and to turn them into high value‐added material for a sustainable contribution to a circular carbon economy.

Ether Bond Formation in Waste Biomass–Derived, Value-Added Technical Hardwood Kraft Lignin Using Glycolic Acid

Ether bond formation in technical hardwood kraft lignin (THKL) by crosslinking using glycolic acid was investigated for bio-adhesive applications. Industrial hardwood kraft black liquor was used to extract the THKL utilized by acidification. Chemical and thermal properties of the THKL with and without crosslinking were analyzed by Fourier transform infrared (FTIR) spectroscopy, solid-state 13C cross-polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). FTIR results revealed a new peak corresponding to the ether bond and hemiacetal formation due to crosslinking at 1075 cm-1 and 1324 cm-1. 13C CP/MAS NMR spectra revealed the presence of a higher number of ether bonds due to the reduced aromatic and aliphatic hydroxyl groups in THKL and new bonds formed at 62-64 ppm and 168-191 ppm due to crosslinking. XPS results revealed that new bonds were formed between glycolic acid and THKL, leading to increased atomic oxygen percentage and carbon–oxygen bonds in crosslinked THKL detected by peak intensity changes at 287.7 and 288.8 related to O–C–O and O–C=O. Also, the oxygen content increased from 14.88% to 31.76% due to bond formation. GPC confirmed a higher molecular weight and broader molecular-weight distribution of THKL. DSC and TGA curves of crosslinked THKL revealed exothermic behavior, high thermal stability, and low thermal degradation rate. Owing to a significant amount of kraft black liquor being generated by wood pulp industries and attractive chemical properties of THKL, THKL demonstrates promise as a raw material to produce green, sustainable bio-adhesives via the crosslinking of its different hydroxyl groups using glycolic acid.

Impact of ball milling on the cubic Sb2O3 into orthorhombic Sb2O3 and SbO2 materials – Structural and other characterization studies

The present investigation adds new information about the cubic Sb2O3 and orthorhombic Sb2O3 and SbO2 phases to the scientific society. In this work, the Sb2O3 (commercial) powder was ball-milled in a tungsten carbide (WC) jar using WC balls with different diameters at 300 ​rpm for several time intervals (1, 3, 5, 10, 20, and 30 ​min and 1, 2, 5, 10, 20, and 30 ​h) and reported their findings of structural, thermal, optical, and morphology. Interestingly, the ball-milled powder undergoes phase transformation from cubic Sb2O3 into orthorhombic Sb2O3 and SbO2 in a short duration (3–30 ​min) of ball milling. While the 0, 1, and 3 ​min ball milled samples preserve the cubic Sb2O3 structure, the 5 ​min ball milled sample exhibits a nearly single-phase orthorhombic Sb2O3 structure. Mixed phases of orthorhombic Sb2O3 and SbO2 phases are seen for the 10–20 ​min ball milled samples. For a 30 ​min ball milled sample, an orthorhombic SbO2 phase is observed. Furthermore, the 1, 3, 5, 10, 20, and 30 ​h ball milled samples retain the orthorhombic SbO2 phase. Maximum weight loss of 34.4 ​% is noted for the commercial Sb2O3 powder, whereas the 1 and 3 ​min of ball-milled samples reveal the weight loss of 9.3 and 4.7 ​%, respectively. The other ball-milled samples exhibit both weight loss and weight gain in the thermogravimetric analysis (TGA) curves. The Raman features of ball-milled orthorhombic SbO2 are quite different from those of other types of antimony-based oxides. Bar/bundle-shaped and spherical-shaped with agglomerated particles are seen for the commercial Sb2O3 phase and ball-milled (1 and 30 ​h) SbO2 phase samples.

New Heteroleptic Germanium Precursors for GeO2 Thin Films by Atomic Layer Deposition.

This study describes the synthesis of 12 new germanium complexes containing β-diketonate and/or N-alkoxy carboxamidate-type ligands as precursors for GeO2 through atomic layer deposition (ALD). A series of Ge(β-diketonate)Cl complexes such as Ge(acac)Cl (1) and Ge(tmhd)Cl (2) were synthesized by using acetylacetone (acacH) and 2,2,6,6-tetramethyl-3,5-heptanedione (tmhdH). N-Alkoxy carboxamidate-type ligands such as N-methoxypropanamide (mpaH), N-methoxy-2,2-dimethylpropanamide (mdpaH), N-ethoxy-2-methylpropanamide (empaH), N-ethoxy-2,2-dimethylpropanamide (edpaH), and N-methoxybenzamide (mbaH) were used to afford further substituted complexes Ge(acac)(mpa) (3), Ge(acac)(mdpa) (4), Ge(acac)(empa) (5), Ge(acac)(edpa) (6), Ge(acac)(mba) (7), Ge(tmhd)(mpa) (8), Ge(tmhd)(mdpa) (9), Ge(tmhd)(empa) (10), Ge(tmhd)(edpa) (11), and Ge(tmhd)(mba) (12), respectively. Thermogravimetric analysis curves, which mostly exhibited single-step weight losses, were used to determine the evaporation properties of complexes 1-12. Interestingly, liquid complex 2 has no residue at 198 °C and therefore exhibits excellent vaporization properties and high volatility. Single-crystal X-ray diffraction studies of 1 and 7 demonstrated that the complexes had monomeric molecular structures with germanium chelated by the oxygen atoms of one or two bidentate ligands, respectively. An ALD process was developed for the growth of GeO2 using Ge(tmhd)Cl (2) as a new precursor and H2O2 as an oxidant. This study demonstrates the achievement of self-limiting growth of GeO2 films by varying the duration of injection/purge, with an observed ALD window at deposition temperatures ranging from 300 to 350 °C. The saturated growth per cycle of the GeO2 film was determined as 0.27 Å/cycle at a deposition temperature of 300 °C. The deposited films were observed to be amorphous consisting of GeO2.

Kinetics and thermodynamic analysis of palm oil decanter cake and alum sludge combustion for bioenergy production

The main purpose of this research is to explore the thermo-kinetics of the combustion process involving palm oil decanter cake (PODC) and alum sludge (AS) for bioenergy production. Thermogravimetric analysis (TGA) was utilized for the investigation and analyzing of the combustion characteristics. Coats-Redfern methods was applied to estimate the activation energy (Ea) and pre-exponential factor (lnA) using twelve reaction mechanisms. TGA curve revealed that unlike PODC, AS and blends exhibit two degradation ranges. The mass loss of PODC/AS co-combustion reduced with AS addition. Kinetic study revealed that for range I, 50PODC+50AS has the best reaction rate with models P3 and P4. Ea and lnA for P3 and P4 model are (13.52 kJ/mol and 7.19 min−1) and (11.13 kJ/mol and 6.57 min−1) respectively. ΔH, ΔG, ΔS for P3 and P4 models are (8.4 kJ/mol, 131.15 kJ/mol, −0.2 kJ/mol.K) and (6.02 kJ/mol, 131.96 kJ/mol, −0.21 kJ/mol.K) respectively. For range II, 50PODC+50AS has the best reaction rate with model A3. The Ea and lnA for A3 model are 41.40 kJ/mol and 12.36 min−1 respectively. ΔH, ΔG, and ΔS for A3 model are 35.16 kJ/mol, 153.84 kJ/mol, and 0.16 kJ/mol.K respectively. Overall, 50PODC+50AS demonstrated the highest reaction rate, suggesting its superior suitability for bioenergy production.

Pyrolysis of municipal solid waste compost: Pilot plant evaluation as a sustainable practise of waste management.

To evaluate the potential of compost based on municipal solid waste (MSW) and 20% legume pruning under a pyrolysis process, generated products, including solids (biochar), liquids (bio-oil), and gases (non-condensable gases), through experimentation in a pilot plant with a fluidized bed reactor at 450°C and gas chromatography/mass spectrometry have been analysed. In addition, the compost kinetic behaviour by thermogravimetric analysis (TGA), using the Flynn-Wall-Ozawa (FWO) method, has been investigated. Four different reaction zones, associated with lignocellulosic materials (hemicellulose, cellulose, and lignin) with a first step for water evaporation, in TGA curve have been observed. A biochar with low stability and aromaticity, considering high and low O/C and H/C ratios, respectively, has been obtained. The obtained pyrolytic liquids contain a high concentration of phenolic compounds because of a significant presence of lignins and other high molecular weight compounds in the original material. Moreover, the generated non-condensable gases consist mainly of short-chain compounds, such as alcohols, aldehydes, and alkenes produced from hemicellulose, cellulose, and proteins.

Evaluation of the Intermediate Values of the TGA Curves as Indicators of the Proximal Analysis of Biomass

Thermogravimetric analysis (TGA) is becoming popular for the evaluation of biomass to determine the content of ashes, volatiles, and fixed carbon and to simulate pyrolysis, gasification, and combustion processes. This analysis consists of heating a sample recording the weight variation as the temperature increases over time. The final temperature of the analyzes is usually set at 550 °C or 900 °C. The aim of this paper is to use the intermediate weight values obtained in short times from heating process in TGA to calculate the percentage of volatile, ash, or the residual mass remaining at the end of the experiment. Under the hypothesis that the curve does not vary when the analysis is carried out under certain conditions for the same type of biomass, these values must be similar and are related to the searched values. Nevertheless, given that the behavior of the thermogravimetric curves can be influenced by different factors, such as the species, temperature variation with time, final temperature reached, and presence of leaves, these factors are analyzed in this article. The results show models developed for the ash and volatiles determination from TGA time reduced to 75 s when a temperature increase of 200 °C per minute is used (CR-200 and VR-200 models). The curves obtained have R2 coefficients of between 0.75 and 0.95, being validated through independent samples. It is shown that the plot of the curve is influenced by the composition, the rate of heating and the percentage of leaves. This variability makes it necessary to select an analytical method that is efficient and as brief as possible. In this article, rapid analyses combined with the application of the equations obtained are proposed.

A novel green synthesis approach for shape memory polymer nanocomposites decorated with silver nanoparticles

AbstractA new, low‐cost, and direct green synthesis strategy was developed for the preparation of polymer composites composed of silver nanoparticles (AgNPs) decorated on a shape memory polymer blend using Rubus caesius L. leaves. X‐ray powder diffraction, ultraviolet‐visible spectroscopy (UV–vis), scanning electron microscopy, and energy dispersive X‐ray spectroscopy (EDS) elemental composition were applied to characterize the crystal size, morphology, and elemental composition of Ag‐NPs. UV–vis spectra detected the characteristic absorbance signal of AgNPs at about 430 nm, and the average crystal size of nanoparticles was calculated as about 12.60 nm. When nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy, characteristic polylactic acid, and poly ethylene glycol (PEG) signals were determined. From the thermogravimetric analysis curves, it was determined that the amount of residue of nanocomposites increased as the amount of AgNP increased. It was seen that AgNPs did not affect the Tg temperature of the nanocomposite films, while it was also a proof that the polymer blend was immiscible. It was observed that the shape recovery properties of nanocomposite films were better with increasing AgNPs content. Finally, both green synthesized AgNPs and nanocomposites prepared with shape memory polymers showed very good antibacterial activity against Gram‐positive and Gram‐negative bacteria.Highlights Green synthesis of silver nanoparticles (AgNPs) was carried out with Rubus caesius L. leaves. The synthesized AgNPs were characterized by ultraviolet visible spectroscopy and x‐ray powder diffraction. Composite films were prepared with poly lactic acid/poly ɛ‐caprolactone blend by solvent casting method. The amount of residue of nanocomposites increased with increasing AgNPs percentage. The nanocomposite film containing 10% AgNPs has good activity.

The effect of modified carbon-doped boron nitride on the mechanical, thermal and γ-radiation stability of silicone rubber composites

The developing nuclear technology has increased the need for radiation-resistant and shielding materials. It is crucial to study the radiation resistance of polymers in order to prevent safety incidents brought on by the degradation of polymer performance in a nuclear environment. In this work, γ-aminopropyltriethoxy silane (KH550) was successfully grafted onto carbon-doped boron (BCN) to obtain modified BCN (BCN-KH550), then BCN-KH550 was added in silicone rubber and refined and vulcanized. The elongation at break of silicone rubber composite doped with 0.3 phr BCN-KH550 can retain (54 ± 2)% of the initial value. The addition of BCN and BCN-KH550 both increases the initial decomposition temperature of the irradiated SR. The radiation caused changes in crystallinity and glass transition temperature (Tg) were measured using differential scanning calorimetry. The difference Tg of BCN-KH550/SR0.3 before and after irradiation is 0.9 °C higher than that of SR. It is supposed that BCN protects the side group of SR during irradiation through differential thermogravimetric analysis curve and gas phase infrared spectra of the irradiation-induced gas products. BCN and BCN-KH550 can lower the hydrocarbon, CO2 and CO production by side chain breakdown in both air and nitrogen atmospheres. The presence of BCN and BCN-KH550 decrease the radiation crosslinking of SR. The outcomes demonstrate that BCN-KH550 can reduce the effects of γ-radiation crosslinking on SR by declining side chain decomposition.

Thermal and electrochemical impedance spectroscopy analysis of PAADDA film incorporated with Li2SO4

In this paper, poly(acrylamide-co-dialidimethylamonium)-PAADDA films containing lithium sulfate (Li2SO4) were prepared by casting method from aqueous solutions. The obtained films (pristine PAADDA, PAADDA/Li2SO4-0.25% w/w, and PAADDA/Li2SO4-0.5% w/w) were characterized by means of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and electrochemical impedance spectroscopy (EIS). ATR-FTIR spectra of PAADDA/Li2SO4 films showed the main bands of PAADDA and suggested a significative intermolecular interaction between the polymer and Li2SO4. TGA curves displayed that the thermal stability of PAADDA film is dependent on the Li2SO4 concentration. The ionic conductivity of the films followed the order: PAADDA/Li2SO4-0.25% w/w < pristine PAADDA <PAADDA/Li2SO4-0.5% w/w.

Adsorption Characteristics of Water Ciprofloxacin on Co‐Pyrolysis Biochar Derived from Rubber and Ginkgo Biloba Leaves

AbstractTaking rubber and ginkgo biloba leaves as raw materials (the mass ratio is 5 : 2), this study prepared biochar by co‐pyrolysis at 700–900 °C and explored its adsorption performance on the emerging water pollutant ciprofloxacin. The pyrolysis behaviors of rubber, ginkgo biloba leaves, and their mixture were investigated using a thermogravimetric analyzer. The microstructure and physicochemical properties of the co‐pyrolysis biochar prepared in this study were probed through scanning electron microscopy (SEM), Brunauer‐Emmett‐Teller (BET) and element analysis. Meanwhile, the internal mechanism of prepared co‐pyrolysis biochar adsorbing ciprofloxacin was investigated using adsorption kinetics models and isotherm adsorption models. The results show that there is a synergistic effect between rubber and ginkgo biloba leaves during the co‐pyrolysis process. Due to the addition of ginkgo biloba leaves, the maximum mass loss rate of rubber reduces from −5.80 %/min to −4.98 %/min, the corresponding pyrolysis temperature decreases from 335.11 °C to 319.57 °C, and the calculated thermogravimetric analysis (TG) and differential thermogram (DTG) curves after mixing the two raw materials deviate from the experimental curves. As the pyrolysis temperature increases from 700 °C to 900 °C, the yields of biochars decrease from 28.62 % to 19.21 %, while the specific surface area significantly increases (337.5042 m2/g). The processes of co‐pyrolysis biochars prepared at different temperatures absorbing ciprofloxacin conform to the pseudo‐second‐order model (R2=0.9847, 0.9404 and 0.9772, respectively). The Langmuir‐Freundlich model describes the isotherm adsorption behaviors of co‐pyrolysis biochars prepared at different temperatures on ciprofloxacin excellently (R2=0.9976, 0.9995 and 0.9993). The co‐pyrolysis biochar prepared at 900 °C has the highest adsorption capacity for ciprofloxacin, 306.6 mg/g. This study provides an essential reference for the application of co‐pyrolysis biochar of low‐cost and environment‐friendly in the removal of water pollutants.

Growth and Characterization of Organic 2-Chloro 5-Nitroaniline Crystal Using the Vertical Bridgman Technique

In this article, we discuss the preparation of organic 2-chloro-5 nitroaniline (2C5NA) crystals and their different kinds of physical, chemical, and mechanical properties. The vertical Bridgman approach was used to effectively produce the bulk organic 2C5NA crystal. To produce a good-quality bulk crystal, the shape, dimensions, and cone angle of the ampoule were optimized. Also, the temperature profile was set for the 2C5NA crystal. The growth atmosphere and the lowering rate were identified to obtain a homogeneous mixture of the compounds and initiate the nucleation process. Single-crystal X-ray diffraction (XRD), powder XRD, proton Fourier transform nuclear magnetic resonance (FT-NMR), and Fourier transform infrared investigations were used to confirm the crystal structure, molecular structure, and presence of functional groups in the formed crystal. The formed crystal has a monoclinic crystal structure with the space group P21/c, according to single-crystal XRD analysis. The thermal stability and kinetic parameters were examined using thermogravimetric analysis and differential thermal curves. From dielectric analysis, the electrical conductivity and dielectric behavior of 2C5NA were investigated with variations in frequency and temperature. The organic 2-chloro-5-nitroaniline crystal demonstrates that the indentation size effect is observed in the Vickers micro-hardness test, which was also carried out.

Fabrication of a low-cost efficient novel Ti3AlC2 MAX phase / Polyvinyl alcohol / Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) polymer nanocomposite film for symmetric supercapacitor

ABSTRACT This work reports a systematic study of the electrochemical performance of the Ti3AlC2 MAX phase/PVA-PEDOT: PSS + DMSO polymer nanocomposite (PPM) films fabricated by the facile solution cast technique. A varying weight percentage of Ti3AlC2 MAX phase nanoparticles were dispersed in the polyvinyl alcohol (PVA)-[poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) + dimethyl sulfoxide)] (PEDOT: PSS + DMSO) polymer blend to fabricate the polymer nanocomposite films. The structural, morphological, optical, thermal, electrical, and electrochemical properties of the nanocomposite films were studied meticulously. The structural and morphological studies were done by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), and field emission scanning electron microscopy (FESEM). The optical properties of the PPM films were analyzed using the UV-Visible (UV-Vis) spectra. The thermal analysis of the PPM films was done from the thermogravimetric analysis (TGA) curves. The ac conductivity and dynamic mechanical analysis (DMA) were done to evaluate the electrical conductivity and mechanical properties of the PPM films. The performance enhancement of the polymer blend film by loading Ti3AlC2 MAX phase nanofiller was investigated. The nanocomposite film having the highest conductivity and the greatest mechanical strength was further considered for the electrochemical characterization. The nanocomposites reported a specific capacitance of 52.8 F/g and 1500 mF/g in 0.1 M HCl electrolyte at a scan rate of 20 mV/s in the 3-electrode system and 2-electrode system, respectively. The Nyquist plots and Bode plots were plotted from the electrochemical impedance spectroscopy (EIS) data. The Nyquist plots were analyzed from the simulated equivalent circuits. The facile fabrication method of the supercapacitor electrode with improved thermal and mechanical properties will be beneficial for their commercial electrochemical applications in the future.

Mechanism research on the application of liquid film microencapsulation technology based on natural lotion in strengthening recycled bio‐composite wallpaper material

AbstractLow‐carbon technology is currently one of the main research directions in sustainable research. The purpose of this research is to explore environmentally friendly low‐carbon technologies to apply NL and wastes to the development of bio‐composite. This research can not only inhibit the release of toxic atmosphere from composite wallpaper materials but also propose new perspective for recycling several bulk wastes such as agricultural waste, waste plastics, and waste cooking oil. This study not only conducted an exploratory research on the degree of filling load from a vertical perspective but also conducted comparative experiments to clarify the strengthening effect of NL in a horizontal perspective. Several valuable findings are obtained through the analysis of several measurements such as mechanical performance and scanning electron microscope (SEM) morphology. The heat transfer effect between components inside the bio‐composite is enhanced by the action of NL. A better heat transfer effect can prevent heat from accumulating in local areas of bio‐composite, resulting in an increase in the overall initial pyrolysis temperature of thermogravimetric analysis (TGA) curve. It is found through experiments that when the biomass filler is excessive, the mechanical performance of the sample sharply decreased. These negative phenomena are presented in the specific form of voids and aggregates in the internal structure of bio‐composite from a microscopic perspective. Comprehensive analysis manifested that NL can suppress the negative effect of filler agglomeration and strengthen the filler/matrix interface bonding. The research also found that the type of biomass filler can affect the actual effect of NL. These findings have certain academic significance and can promote the further development of sustainable research on diversified recycle of wastes.

Heteroleptic Titanium Complexes Bearing Amidoxime Ligands As Precursors for TiN Thin Films ALD

This presentation reports the synthesis of three novel titanium complexes containing amidoxime ligands as potential precursors for titanium nitride (TiN) thin films fabricated using atomic layer deposition (ALD). A series of ligands, viz., N'-methoxy-N-methylacetimidamide (mnnoH), N'-ethoxy-N-methylacetimidamide (ennoH), and N'-methoxy-N-methylbenzimidamide (pnnoH), were successfully synthesized and used to produce Ti(mnno)(NMe2)3 (4), Ti(enno)(NMe2)3 (5), and Ti(pnno)(NMe2)3 (6). Thermogravimetric analysis curves of complexes 4–6 revealed a single-step weight loss up to 200 °C. Pyrolysis occurred beyond 200 °C. Among the three new complexes, 5 was liquid at room temperature. Therefore, an ALD process for the growth of TiN was developed using Ti(enno)(NMe2)3 (5) as a novel precursor. A TiN thin film was deposited from the Ti(enno)(NMe2)3 (5) precursor and NH3 plasma, and self-limiting growth was achieved by varying the injection/purge duration. TiN thin film growths were observed with a growth per cycle (GPC) of 0.03–0.075 nm∙cy-1 at deposition temperatures between 150 and 300 °C, while the measured resistivity was as low as 250 μΩ·cm. The high reactivity of the precursor promotes nucleation, resulting in TiN thin films with smooth, good step coverage, and preferentially orientated microstructure.

Bridgman grown CuSbS2 single crystal and its application as photodetector and potential thermoelectric material

Crystal of copper antimony disulphide (CuSbS2) measuring 4.5 cm in length and 0.8 cm in diameter was successfully grown using the vertical Bridgman technique (VBT). The orthorhombic unit cell structure and pure CuSbS2 phase of the grown crystal was confirmed by the powder X-ray diffraction and was well supported by Raman spectra. The stoichiometry of the grown crystal was confirmed by energy dispersive X-ray analysis and field emission scanning electron microscopy revealed that crystal is grown by layer growth mechanism. The Raman spectra has shown the presence of peak at 319.32 cm−1 corresponding to Sb-S bonds whereas peaks at 445.03 cm−1 and 257.27 cm−1 corresponds to S-S and Cu-S bonds. The photoluminescence spectra taken at room temperature with 488 nm excitation wavelength displays emission in different regions of the visible spectrum. Optical absorbance spectra shows that CuSbS2 single crystal possess direct bandgap of 1.57 eV which is suitable for solar cell application. The Seebeck coefficient is positive over the entire temperature range, demonstrating the sample's p-type semiconducting nature and corroborates our Hall effect measurements. Using electrical conductivity and lattice thermal conductivity values we calculated thermoelectric figure of merit i.e., ZT whose value comes nearly 0.988 at 503 K which stands in competition with reported values of the other grown crystal. Thermogravimetric (TG) curve has shown two step decomposition at four different heating rates of 5, 10, 15 and 20 K/min which is also confirmed from DTG (differential thermogravimetric analysis) curves. At room temperature, the I-V characteristics of prepared CuSbS2 single crystal photodetector are measured for parallel to plane and perpendicular to plane configuration, with various biasing voltages at 50 mW/cm2. At room temperature, a bias voltage of 0.1 V with a light intensity of 50 mW/cm2 yields responsivity and detectivity of 30 mA/W and 32.84 × 106 Jones for ⊥ to plane, which is comparable to the reported values of other materials.

A styrylpyrene‐containing liquid crystal polymer for photoinduced crosslinking

AbstractPhotoresponsive polymers have attracted increasing attention. Herein, we designed and synthesized a photoresponsive liquid crystal polymer (LCP). The LCP was prepared through the copolymerization of a styrylpyrene‐containing photoresponsive monomer and a monomer containing mesogen 4‐cyanophenyl benzoate. Gel permeation chromatography (GPC) curve and 1H nuclear magnetic resonance (1H NMR) spectrum confirmed that the LCP was successfully synthesized. Thermogravimetric analysis and differential scanning calorimetry curves showed that the LCP had high thermal stability, with a decomposition temperature at 5% weight loss of 305°C, and Tg and Ti of 46 and 128°C, respectively. Polarized optical microscopy studies suggested that thermal annealing promoted the orientation of the LCP films. Model compounds containing styrylpyrene units showed photo‐controlled dimerization. Furthermore, the dimerization of the styrylpyrene units could control the crosslinking densities in the LCP, thereby regulating the network structures and properties. These properties demonstrate that the LCP is a promising photoresponsive material.

Biomineralization of carboxymethyl cellulose-sodium alginate infused with cellulose nanocrystals for bone regeneration

The development of novel tissue constructs from both natural and synthetic biopolymers has attracted widespread attention among researchers, prior to its excellent outcomes in bone tissue regeneration. This research aims to investigate the biocompatibility of carboxymethyl cellulose (CMC)/sodium alginate (SA) embedded with cellulose nanocrystals (CNC) and its surface response due to the biomineralization process as potential implant material. The CMC/SA were prepared with and without CNC using water as the only solvent. It was then freeze-dried for up to 72 h before being further immersed in simulated body fluid (SBF) for comparative studies. Morphological observation by scanning electron microscope (SEM) showed that CMC/SA/CNC (SBF) displayed a spherical apatite structure amid interconnected porous materials with an average particle diameter between 95 and 148 nm. The apatite crystal indicated the existence of calcium (Ca) and phosphorus (P) elements, which was confirmed by energy dispersive X-ray analysis (EDX). All scaffolds showed a porosity of up to 90.13% with a moderate degradation rate and a water absorption value of up to 1100%. Overall, all scaffolds had open, interconnected pore sizes ranging from 40 to 400 µm. Attenuated total reflection – Fourier Transform Infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA) curve showed a new existing peak and lower decomposition rate, respectively, for SBF-treated scaffolds. Stress-strain curve disclosed the highest tensile stress of CMC/SA/CNC (SBF) at 16.2 MPa and 15.75% strain effect. Preliminary in vitro cytotoxicity studies performed with human foetal osteoblast (hFOB) cells showed that cytocompatibility was more evident on CMC/SA/CNC (SBF) scaffolds. This study showed that scaffold-embedded CNC with SBF treatment could be hit upon as material selection for bone tissue engineering.

Eco-friendly extraction of cellulose from Ailanthus altissima for nanocellulose production: physico-chemical properties

Abstract Nanocellulose is a promising bionanomaterial which has gained significant attention due to its diverse applications in many important areas. Thus, scientists and technologists are constantly searching for the most economical, sustainable, and eco-friendly production to fulfill its growing need. In this study, cellulose and nanocellulose were isolated from the plant of Ailanthus altissima utilizing a multi-step, environmentally friendly approach involving alkaline treatment and chlorine-free bleaching. The analysis of purified cellulose was conducted by utilizing modern techniques, such as X-ray Diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). XRD analysis determined the degree of crystallinity of extracted cellulose i.e. 67.41 % and crystallite size 43.4 Å by using Segal method and Scherrer equation respectively. The TGA curve showed the thermal degradation pattern of the cellulosic and nanocellulosic material. Furthermore, SEM technique was used to study the morphological changes in the surface of lignocellulosic fibers with chemical treatment. This novel biomass source has to be a potential usage for a wide range of applications in industrial processes.

Effect of sodium lauroyl sarcosinate on the thermal, optical and moisture absorption properties of polyvinylpyrrolidone film

In the present study, polyvinylpyrrolidone films containing amino acid-based surfactant, namely, sodium lauroyl sarcosinate (SLS), were prepared by casting method. The obtained films (PVP/SLS) were characterized by means of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), optical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and moisture absorption (MA). ATR-FTIR spectra of PVP/SLS films showed the main bands of PVP. The opacity of PVP films increased with the addition of SLS. Furthermore, moisture absorption of PVP/SLS films were higher than the pristine PVP film. TGA curves displayed that the thermal stability of PVP film decreased after the incorporation of SLS. DSC curves indicated that SLS can be used as plasticizer for PVP.