TG-DSC Analysis Research Articles

Piperazinium bis (5-chlorosalicylate) – A new third order nonlinear optical single crystal

A new organic single crystal viz, piperazinium bis(5-chlorosalicylate) (P5C) was grown by low temperature solution growth method and its physico-chemical properties were established. The unit cell parameters (a = 11.9306 Å, b = 8.7592 Å, c = 9.3103 Å, α = 90°, β= 100.95°, γ = 90°) were determined by single crystal X-ray diffraction data. The presence of various functional groups in the structure was elucidated by FTIR, Raman and proton NMR spectral studies. The P5C crystal exhibits the good optical tansmittance in the region of 400 to 1200 nm. From photoluminescence studies, the violet emission spectrum was observed under the excitation wavelength of 380 nm. The thermal behaviour of the P5C crystal was analyzed by TG-DSC analysis. The mechanical strength of the grown material classifies it as soft material. The results from Z-scan technique validate the NLO properties. Theoretical calculations like optimized geometry, HOMO-LUMO, mulliken population analysis, natural bond analysis were determined using Gaussian 09W with B3LYP method.

Structural, magnetic and dielectric study of Fe2O3 nanoparticles obtained through exploding wire technique

We propose an exploding wire technique based facile approach to prepare Fe2O3 nanoparticles in ambient conditions. TG-DSC analysis of the prepared precursor (Fe(OH)3) nanoparticles were done. The phase, lattice parameter and the average crystallite size were evaluated through X-ray diffraction analysis. The morphology of prepared nanoparticles was studied by scanning electron microscopy and Transmission electron microscope. The functional group formation of Fe2O3 nanoparticles and intrinsic stretching vibration bands of Fe–O were estimated through FTIR analysis. The direct band gap of Fe2O3 nanoparticles occurring in conjunction with indirect band gaps was established via Tauc plot. The magnetic parameters were studied through Mössbauer spectroscopy, ESR, M-H and M-T plot analysis. The attributes of dielectric behaviour like dielectric constant (ε′), loss tangent (tan δ), dielectric loss (ε″) and alternating current (AC) conductivity (σAC) were measured at various temperatures in the frequency range of 10 Hz-106 KHz.

Recovery lithium and potassium from lepidolite via potash calcination-leaching process

A new comprehensive way to extract lithium and potassium from lepidolite through calcination process with the additive of K2CO3 has been proposed. By using flowing water vapor, the lepidolite concentrate mixed with 58.5% of K2CO3 could generate acid-soluble potassium aluminum silicate (KAlSiO4) and water-soluble lithium/potassium silicate (Li2SiO3/K2SiO3) at 850 °C for 2 h. Additionally, 80% of fluorine could be removed. The reaction feasibility between lepidolite ore and K2CO3 was firstly evaluated through thermodynamic calculation. The decomposition mechanism was explored through XRD and TG-DSC analysis. The experimental results reveal that the decomposition of lepidolite undergoes following phase transformation: trilithionite phase → lepidolite phase → KAlSi2O6 → KAlSiO4. As the desilication process proceeds, silicon is given off and forms lithium/potassium silicate. Through a water leaching process, soluble Li2SiO3/K2SiO3 could be separated from KAlSiO4. The extraction efficiency of Li and K could severally reach 95.52% and 95.70% from soluble silicates through water leaching process, under the optimum conditions. Then the residue KAlSiO4 could be easily recovered by acid solution. This new technique for processing lepidolite could make most of all of its components, as well as being environmentally friendly.

Stabilization of hexavalent chromium with pretreatment and high temperature sintering in highly contaminated soil

This study explored the effectiveness and mechanisms of high temperature sintering following prereduction with ferric sulfate (FeSO4), sodium sulfide (Na2S), or citric acid (C6H8O7) in stabilizing hexavalent chromium (Cr(VI)) in highly contaminated soil. The soil samples had an initial total Cr leaching of 1768.83 mg/L, and Cr(VI) leaching of 1745.13 mg/L. When FeSO4 or C6H8O7 reduction was followed by sintering at 1000°C, the Cr leaching was reduced enough to meet the Safety Landfill Standards regarding general industrial solid waste. This combined treatment greatly improved the stabilization efficiency of chromium because the reduction of Cr(VI) into Cr(III) decreased the mobility of chromium and made it more easily encapsulated in minerals during sintering. SEM, XRD, TG-DSC, and speciation analysis indicated that when the sintering temperature reached 1000°C, almost all the chromium in soils that had the pre-reduction treatment was transformed into the residual form. At 1000°C, the soil melted and promoted the mineralization of Cr and the formation of new Cr-containing compounds, which significantly decreased subsequent leaching of chromium from the soil. However, without reduction treatment, chromium continued to leach from the soil even after being sintered at 1000°C, possibly because the soil did not fully fuse and because Cr(VI) does not bind with soil as easily as Cr(III).

Studies on the development and characterization of bioplastic film from the red seaweed (Kappaphycus alvarezii).

Seaweeds rich in polysaccharides are considered commercially important because of their wide range of industrial applications. In this study, the red seaweed Kappaphycus alvarezii was used for bioplastic film production. Plasticizer polyethylene glycol (PEG) to seaweed biomass ratio was optimized and a thin bioplastic film with higher tensile strength was produced. The films obtained were characterized by its thickness, tensile strength, colour (L, a, b), elongation at break (EAB), water vapour transmission rate (WVTR) and oxygen transmission rate (OTR). TG-DSC, AFM, SEM and FTIR spectroscopy analysis were performed to assess the composition, phase transitions and chemical reaction capabilities of the film. The bioplastic film obtained from 4% K. alvarezii (whole seaweed) showed better physical and mechanical properties, whereas TG-DSC, FTIR and AFM showed similar kind of bioplastic properties in all the concentrations. Decrease in OTR was observed against decreasing wall thickness of the film. The present study suggests that the seaweed would be a potential alternate source for bioplastic production which may reduce the usage of non-degradable plastics.

Sandcastle worm-inspired phytic acid and magnesium oxychloride cement copolymerization for performance enhancement

The development of magnesium oxychloride cement (MOC) can convert wastes in the potash industry into valuable products and reduce CO2 emission. The use of acid radicals has the potential to enhance the water resistance of MOC. However, because of the internal stress formed during the crystallization process, the occurrence of cracks accompanied by a significant decrease in the mechanical properties is inevitable. Inspired by the sandcastle worm and organic-inorganic copolymerization, a novel strategy was proposed, which employed phytic acid (PA) to copolymerize with phase 5 crystals to reduce the internal stress and prevent crack generation. XPS and TG-DSC analyses revealed that organic-inorganic copolymers were successfully produced. Furthermore, the compressive strength (CS) and water resistance of MOC-PA were significantly enhanced. The enhanced properties were associated with the coordination bonds and high tension of the rigid rings in phytic acid, which was sufficient to overcome the internal stress. Additionally, the repeated hydrolysis of rod-like phase 5 generated a gel-like phase from the outside inward, enhancing their water resistance. Compared with MOC-0, MOC-0.6 showed a 17.8% increase in CS and a 102.3% increase in water resistance. The microscopic mechanisms of the enhanced CS and water resistance of high-performance greener cements were proposed.

Kinetics of foaming process of potassium silicate gel at high temperature

The potassium silicate gel with a modulus (molar ratio SiO2/K2O) of 5 was prepared and then sintered in the furnace. As the temperature increased, the gel began to foam and its volume reached a maximum at 550 °C, close to 33.5 times the initial volume. After 550 °C, the sharp decrease in foam volume is due to the obvious densification of the gel in the glass transition temperature region. TG-DSC analysis and IR absorption spectra were employed to characterize the foaming process of the gel. The results show that water is the driving force for the foaming process of the potassium silicate gels. The sources of water are different at different stages of foaming, including molecular water, adsorbed water and water produced by the polymerization of silanol groups.

Biomineralization, dissolution and cellular studies of silicate bioceramics prepared from eggshell and rice husk.

The current investigation aims to replace the synthetic starting materials with biowaste to synthesize and explore three different silicate bioceramics. Pure silica from rice husk was extracted by decomposition of rice husk in muffle furnace followed by alkali treatment and acid precipitation. Raw eggshell and extracted silica were utilized for the preparation of wollastonite, diopside and forsterite by the solid-state method. The TG-DSC analysis shows that the crystallization temperature of wollastonite, diopside and forsterite was found to be 883°C, 870°C and 980°C, respectively. The phase purity of wollastonite was attained at 1100°C whereas diopside and forsterite were composed of secondary phases even after calcination at 1250°C and 1300°C respectively. All three materials behaved differently when exposed to the physiological environment, as wollastonite exhibited remarkable apatite deposition within 3days whereas a distinct apatite phase was noticed on the surface of diopside after 2weeks and forsterite shows the formation of apatite phase after five weeks of immersion. The rapid dissolution of Mg2+ ion from forsterite lowered the leaching of silicate ions into the simulated body fluid leading to poor apatite deposition over its surface. Chemical composition was found to plays a key role in the biomineralization ability of these bioceramics. Hemolysis and Lactate Dehydrogenase (LDH) release assays were performed to evaluate the hemocompatibility of silicate ceramics cultured at different concentrations (62.5, 125, and 250μg/mL) with red blood cells and mononuclear leucocytes (MLs) of mice. The hemolytic activity of all the tested bioceramics was insignificant (less than 1%). The interaction between diopside and mouse multipotent mesenchymal stromal cells (MMSCs) caused a negligible increase in the number of apoptosis-associated Annexin V-binding cells whereas forsterite and wollastonite induced an increase in the number of the apoptotic cells only at the concentration of 250μg/mL. The LDH assay did not show statistically significant changes in the proliferation of MMSCs after treatment with the bioceramics at the tested concentrations when compared to control (p>0.05). This finding showed that the death of a part of cells during the first 24h of incubation did not prevent the proliferation of MMSCs incubated with diopside, forsterite and wollastonite for 72h.

Synthesis and Adsorption Properties of Novel Bacterial Cellulose/Graphene Oxide/Attapulgite Materials for Cu and Pb Ions in Aqueous Solutions.

Removing heavy metal ions from industrial wastewater is one of the most important and difficult areas of the water treatment industry. In this study, Bacterial Cellulose/Polyvinyl Alcohol/Graphene Oxide/Attapulgite (BC/PVA/GO/APT) composites were successfully prepared via a repeated freeze-thaw method using bacterial cellulose, polyvinyl alcohol as the skeleton, and graphene oxide, attapulgite as fillers. The capacities of adsorbing Cu2+ and Pb2+ ions in solution were investigated. FTIR, XRD, SEM, BET, and TG-DSC analyses showed that the BC/PVA/GO/APT hydrogel has a better hydrophilicity, a larger specific surface area and a better thermal stability than traditional materials. We found that the adsorption of Cu2+ and Pb2+ ions can be accurately predicted by the Freundlich kinetic model, and the optimal adsorption capacities of these ions were found to be 150.79 mg/g and 217.8 mg/g respectively. Thermodynamic results showed that the adsorption process is spontaneous and exothermic. BC/PVA/GO/APT composites are suggested to be an ideal adsorption material for removing heavy metal ions from industrial wastewater.

Investigation on the growth, optical, electrical, thermal and third order NLO properties of 2-(4-methlybenzylidene) malononitrile (MBM) single crystal

More effective organic charge transfer nonlinear optical material of 2-(4-methlybenzylidene) malononitrile (MBM) has been synthesized via knoevenagel condensation reaction method and single crystals of unprecedented MBM were successfully cultivated in the presence of ethanol solution by the adaption of slow evaporation solution growth method. Cell parameters and phase purity of the obtained MBM crystals were investigated with the help of Single crystal and powder X-ray diffraction analysis. The morphology of the grown crystal was generated using WinXMorph software. Linear optical characterization was carried out in order to figure out its transmittance efficiency (82%), cut-off wavelength (λ = 458 nm) and energy band gap (Eg = 3.05eV) of the title material. Electrical behavior of the MBM crystal was examined on the basis of dielectric properties. Title crystals thermal tolerance and melting point was examined through TG-DSC analysis. The grown MBM crystal was subjected to Single beam Z-scan technique in order to figure out its third order nonlinear optical nature and its susceptibility is compared with other reported centrosymmetric crystals. Considering its large transmittance range, thermal stability and effective NLO performance, MBM is a potential candidate for NLO applications.

Influence of polypropylene and nanoclay on thermal and thermo-oxidative degradation of poly(lactide acid): TG-FTIR, TG-DSC studies and kinetic analysis

Compatibilized poly(lactic acid)/polypropylene (PLA/PP) blends with a drop-matrix morphology containing 25 wt.% PP, 5 wt.% ethylene/n-butyl acrylate/glycidyl methacrylate terpolymer (PTW) as compatibilizer, and 5 wt.% nanoclay were prepared by one-step mixing process in a twin-screw extruder. TEM analysis revealed that the clay particles were mainly localized in the PLA matrix phase in the absence of PTW; by contrast, the addition of compatibilizer changed the location to the blend interface. Multiple rate thermogravimetric analysis revealed two-stage and single-stage weight losses under neutral and air atmospheres, respectively. To reveal the influence of blending, nanoclay inclusion and compatibilization process on the PLA degradation process, a systematic quantitative evaluation of degradation processes was carried out based on kinetic parameters derived from model-free and model-fitting analyses. The results revealed that the activation energy of the thermo-oxidative process, being significantly lower than that of the thermal pyrolysis, greatly increases in the presence of nanoclay, indicating the accelerating role of oxygen in the degradation process and the barrier effect of nanoclay against oxygen diffusion. The combined TG-DSC analysis in the nitrogen environment confirmed the appearance of endothermic signals being proportional to the sample weight loss, which is characteristic of thermal pyrolysis. Subsequently, in an oxygen-containing environment, initial exothermic peaks were formed, which was attributed to the oxidative degradation of the sample. As the reaction progressed, secondary peaks were observed due to the degradation of residuals formed in the first stage of the degradation process. Also, for chemical analysis of volatiles, simultaneous TG-FTIR analysis was employed in a neutral atmosphere at the maximum degradation temperature. Lactide, acetaldehyde, carbon dioxide (CO2) and carbon monoxide (CO) were the products obtained from the degradation process of the PLA phase.

Effect of La promotion on Ni/Mg-Al hydrotalcite derived catalysts for glycerol steam reforming

Abstract The influence of lanthanum promotion on the physico-chemical properties and catalytic activity of Ni/Mg-Al catalysts in the glycerol steam reforming (GSR) reaction was studied. An Mg-Al and different Mg-Al-La supports with various molar ratios were synthesized using a co-precipitation technique. The calcined supports were then impregnated with 5 wt% Ni. After calcination at 600 °C, physico-chemical properties of the Ni-based catalysts were investigated by XRD, BET, H2-TPR, and CO2-TPD techniques. H2-TPR analyses showed that the quantity of lanthanum in the support composition influenced the reducibility of Ni species as well as their dispersion. CO2-TPD analyses showed that lanthanum addition improved catalyst basicity. The activity of all catalysts in the GSR reaction was tested (T = 400−700 °C, water/glycerol feed ratio 9:1, flow rate of 0.025 mL/min). The composition of the Ni/MAL0.4 (Ni/Mg6Al1.6La0.4; subscripted numbers indicate the molar ratio of each metal) catalyst provided a good metal-support interaction and Ni dispersion which translated to an overall superior performance in terms of hydrogen yields, glycerol conversion to gaseous products, and total glycerol conversions. TG-DSC analyses of the spent catalysts showed that the lanthanum quantity also influenced the quantity of coke deposition. The formation of encapsulating coke over all catalysts was linked to high concentrations of dehydration products observed in liquid product analysis. A stability test conducted at 600 °C for Ni/MAL0.4 revealed its deactivation due to encapsulating coke formation which resulted in active metal site blockage. With a reduced flow rate (0.008 mL/min), a different coke formation mechanism allowed the catalyst to last for 24 h.

Characterization of Bioactive Glass Synthesized by Sol-Gel Process in Hot Water

Bioactive glass 70SiO2-30CaO (mol.%) was successfully synthesized by modified sol–gel in hot water without using an acid catalyst. TG-DSC analysis showed that the amorphous glass could be synthesized by sintering the sample at 700 °C for three hours. The N2 adsorption/desorption and TEM investigations highlighted that the synthetic glass had a mesoporous structure, consisting of spherical particles with sizes in the range of 11–20 nm. The specific surface area, pore volume, and average pore diameter of synthetic glass were 150.13 m2/g, 0.37 cm3/g, and 11.84 nm, respectively. Moreover, synthetic bioactive glass presented interesting bioactivity and good biocompatibility after in vitro experiments in simulated body fluid (SBF) and in cellular medium.

Resource utilization of chlorosilane residual liquid to prepare nano-silica in reverse microemulsion system

Nano-silica particles were prepared using chlorosilane residual liquid as raw materials in an inverse microemulsion system formed by three different surfactants (TX-100, CTAB, SDS) with n-hexanol, cyclohexane, and ammonia. The phase behavior of inverse microemulsions and the preparation of nano-silica were investigated. The results showed that the system composed of non-ionic surfactant TX-100 had a larger inverse microemulsion region than other two system and was more suitable for the preparation of nano-silica. The prepared nano-silica had uniform sphericity and good dispersibility, the average particle diameter of 31 nm, and the variance of 1 nm. XRD, FT-IR, N2 adsorption/desorption experiments and TG-DSC analysis were used to characterize the prepared nano-silica. The results showed that the prepared nano-silica was amorphous mesoporous silica with a BET specific surface area of 472.5 m2/g. They have a good thermal stability, and the phase structure and main chemical functional groups of nano-silica would not change after calcination at 600 °C, but the nano-silica would undergo a phase change at 1135 °C, which changed from amorphous to crystalline. The new technology not only broadened the source of preparation of nano-silica materials, but also provided new ideas for the treatment of chlorosilane residual liquid and the sustainable development of polysilicon industry.

Study on PVA-siloxane mixed emulsion coatings for hydrophobic cement mortar

Efflorescence is widely regarded as a serious problem in cement-based exterior wall. This phenomenon can affect the appearance and long-term stability of the building. Based on the efflorescence mechanism, one of the causes of efflorescence is the existence of free water to dissolve soluble salts. Therefore, we propose a method for synthesizing hydrophobic cement mortar. The main challenge of the super-hydrophobic coating is its robust durability. To synthesize durable hydrophobic cement mortar, we use PVA as an adhesive to enhance the durability of the coating, and use siloxane material as a hydrophobic agent, through high-speed mixing, to obtain a PVA-coated siloxane material hydrophobic coating. Optical microscope and scanning electron microscope (SEM) and FT-IR spectroscopy were utilized to characterize the emulsions and coatings. Appearance analysis of the coatings was performed using a colorimeter and UV Spectrophotometer, and the durability of the coating was evaluated by abrasion resistance and water resistance. The measured water contact angles (CA) are between 120° to 140°, and the water absorption after 24 h and 48 h can be reduced by about 10 % and 15 % compared with the reference sample, including the water absorption coefficient is approximately lower than the untreated group 1.7–4 times. Finally, accelerated efflorescence test, image acquisition and analysis with Matlab software, determination of calcium ion leaching rate and TG-DSC analysis were performed. The results show that the cement mortar treated with hydrophobic emulsion has excellent water resistance and improved efflorescence resistance, and can be widely used in cement-based buildings.

Growth, experimental and theoretical investigations on 4-hydroxy-3-methoxybenzaldehyde 5-chloro-2-hydroxybenzoic acid: A new high second order nonlinear optical material

Novel 4-hydroxy-3-methoxy benzaldehyde 5-chloro-2-hydroxybenzoic acid (4H5C) organic co-crystal was grown by simple solution growth technique. 4H5C crystal exhibits the orthorhombic structure with non-centrosymmetric space group of Pna21 from single crystal X-ray diffraction study results. The cut-off wavelength and optical excitation wavelength was evaluated by using UV–Visible and PL spectral studies to the 4H5C heterodimer and suitability for the NLO applications are discussed. 4H5C single crystal material thermal stability and decomposition states were examined by using TG-DSC analysis. Vickers microhardness test was carried out on the flat surface of 4H5C crystal to understand the mechanical strength and behavior for weight loadings. Chemical etching patterns of 4H5C crystal surface was carried out and found the layer growth pattern. The second harmonic generation (SHG) efficiency of 4H5C single crystal was evaluated by Kurtz-Perry powder technique and result is compared with KDP crystal SHG efficiency. Polarizability, first order hyperpolarizability, geometric parameters of 45HC were evaluated theoretically by using B3LYP, CAMB3LYP methods of density functional theory by using 6-311++G (d,p) basis set. It is estimated that, the polarizability (3.38 x 10−23 e.s.u) and first order hyperpolarizability (9.370 x 10−30 e.s.u.) to the 4H5C heterodimer in B3LYP method.

Novel lanthanide(III) complex [LaL2(NO3) (H2O)2]·5H2O with 2-pyridine carboxaldehyde isonicotinoyl hydrazine exhibiting a 3D supramolecular topology 3,6T49

A new coordination compound, namely [LaL2(NO3)(H2O)2]·5H2O (1), has successfully been synthesized from La(NO3)3·6H2O, 2-pyridinecarboxaldehyde isonicotinoylhydrazone (HL) and NaOH, as a deprotonated agent, in the CH3OH medium under mild solvothermal conditions at 120 °C. Both HL and 1 were characterized by FTIR spectroscopy and elemental analysis. Complex 1 was also studied by the simultaneous TG-DSC, powder and single crystal X-ray diffraction analyses. According to the single crystal diffraction analysis, the lanthanum (III) ion adopts a deca-coordinated mode, and five lattice water molecules exist in the asymmetric unit. The crystal structure of 1 is mainly stabilized by strong O–H⋯N and O–H⋯O and weak π⋯π and C–H⋯π interactions. As a result of hydrogen bonding, a 3D supramolecular structure is formed with a binodal (3,6)-connected network with a 3,6T49 topology having point symbol of {4∙62}{47∙65∙83}. As evidenced from the Hirshfeld surface analysis of [LaL2(NO3)(H2O)2], intermolecular H⋯H (40.1%), H⋯C (15.4%), H⋯N (12.2%) and H⋯O (20.3%) contacts occupy an overwhelming majority of a molecular surface of the complex molecule. Highly favoured intermolecular C⋯C (6.5%) and C⋯N (4.0%) contacts also play a vital role in the supramolecular structure of complex. Upon heating, complex 1 decomposes in few steps, consistently losing lattice water molecules, coordinated water molecules followed by the decomposition of organic ligands, yielding La(NO3)3 followed by the formation of a final residue La2O3.

Study on Mechanically Activated Dioscorea Fiber and Analysis of Activation Energy

Microtopography of fiber of Discorea nipponica Makino before and after mechanical activated by AGO-2 planetary mill was observed by SEM, and they changed the thick floccules to fine particles (D50 particle sizes were 10.18μm). Discorea fiber powder after mechanical activation had a narrow size distribution. According to XRD, the granularity and structures of discorea fiber with and without mechanical activation significantly differed, and the crystalline of discorea fiber was significantly converted into amorphous state after mechanical activation. On the basis of TG–DSC analysis, the activity of discorea fiber was enhanced, and certain internal energy were stored, and complete decomposition in advance. According to FT-IR, none of the functional groups of the mechanically activated discorea fiber disappeared, and no new functional groups appeared, which indicate that mechanical activation does not induce a chemical transformation of discorea fiber. According to the activation energy analysis, the thermal activation energy of dioscorea fiber after mechanical activation was18.49 kJ•mol, and the mechanical transfer activation energy was 56.06 kJ•mol, indicating that about 1/3 of the mechanical transfer activation energy was stored in the activated dioscorea fiber fine powder in the form of surface energy and internal energy.

Hydrothermal synthesis, crystal and electronic structure of a new hydrated borate CsKB4O5(OH)4·2H2O

Hydrothermal method successfully produced a new cesium-metal borate (CsKB4O5(OH)4·2H2O). The crystals are grown in the P21/c space group with a monoclinic lattice, a = 10.7298 (13) Å, b = 8.1521 (11) Å, c = 13.2690 (15) Å, β = 108.325 (9)°, and Z = 4. The structure is composed of [B4O5(OH)4]2- groups connected to 8-coordinated potassium, 12-coordinated cesium ions, and water molecules forming the final 3D framework. FTIR and Raman spectra identified the type and nature of the borate groups within the structure. UV-Vis- NIR diffuse reflection spectra have studied the transmission property, whereas TG-DSC analyses revealed the thermal stability of the crystals. In addition, theoretical calculations have been executed to understand the density of states and band structure.

Synthesis of starch graft-copolymers via reactive extrusion and their ammonium sorption properties

The limiting features of existing ammonium-recovery technologies, such as pH-dependency, inefficient manufacturing, and low removal capacity of ammonium sorbents, limit their commercial application potential. To overcome these technical limitations, we employed reactive extrusion (REx) as a sustainable alternative synthesis method to prepare cost-effective ammonium sorbents based on starch-copolymers.This paper describes the graft copolymerization of starch with acrylamide and 2-acrylamido-2-methylpropane-sulfoacid monomers using twin-screw extrusion technology and evaluates the resulting products’ structural features and ammonium uptake capacity. The relationship between the starch molecular structure and effectiveness of the REx process was studied by monitoring the specific mechanical energy, die pressure and torque during the extrusion process. The impact of the starch features on the product’s chemical structure, thermal resistance, and swelling capacity was also determined. The ATR-FTIR, 1H NMR, and TG-DSC and elemental analysis confirmed the success of the proposed REx method for producing starch-copolymers, with an average graft efficiency of ∼65% across all samples. The starch structure and chemical composition controlled the grafting reaction efficiency, but had limited influence on monomer conversion. Cationic starch produced amphoteric copolymers that behaved similarly to acrylamide-based polyampholytes in electrolyte solutions. The starch- copolymer’s adsorption capacity increased proportionally with the initial ammonium concentration and remained constant within the pH range of ∼5.5–8.5. A monolayer adsorption capacity of ∼23 mg/g was recorded for the as-prepared starch-copolymer at 25 °C, comparable with those of the hydrogel sorbents at ambient temperature. This study highlights the potential of the as-prepared starch-copolymers as a cost-effective material solution for achieving sustainable ammonium removal.