Papers by Keyword: Polyethyleneimine

Abstract: Synthetic dyes such as methyl orange (MO) are persistent water pollutants that pose serious environmental and health hazards due to their toxicity and resistance to biodegradation. Developing efficient, sustainable, and reusable adsorbents for dye removal remains a major challenge in wastewater treatment. This study presents the design and optimization of chitosan/polyethyleneimine/graphene oxide (CS/PEI/GO) hydrogel nanocomposite beads synthesized through controlled cross-linking with glutaraldehyde (GLA) for enhanced adsorption of MO from aqueous solutions. A Box–Behnken experimental design coupled with response surface methodology (RSM) was employed to evaluate the effects of PEI, GO, and GLA concentrations on adsorption capacity. Statistical analysis confirmed the high significance of the cubic model (F = 38.34, p = 0.0001) with a non-significant lack of fit, validating its strong predictive reliability. PEI concentration had the most pronounced effect, providing protonated amine sites for electrostatic interaction with the anionic dye, while GO increased surface area and provided oxygen-containing groups that enhanced hydrogen bonding and π–π interactions. GLA served as a cross-linker to stabilize the hydrogel structure without deactivating active sites. The optimized composition (2.0% PEI, 900 ppm GO, and 2.5% GLA) achieved a predicted adsorption capacity of 23.16 ± 1.05 mg/g, which closely matched the experimentally obtained value of 23.31 ± 1.19 mg/g, with only 2.2% deviation. These findings confirm that the CS/PEI/GO hydrogel nanocomposite provides a balanced integration of structural stability, functional site availability, and high adsorption efficiency, demonstrating its potential as a scalable, eco-friendly material for advanced dye removal and sustainable wastewater treatment.

Abstract: Adsorbent beads composed of Chitosan (CS), MIL-101 (Fe), and Polyethyleneimine (PEI) were synthesized for Methyl Orange (MO) adsorption. Parametric studies testing the effects of pH and number of adsorption and desorption cycles on percent MO removal showed the beads’ good performance across a wide range of conditions. A percent MO removal of at least 93% was maintained from pH 2 to pH 9 with a maximum percent removal of 98.6% obtained at pH 3. In addition, the beads remained functional for at least 5 cycles of adsorption and desorption with a percent MO removal of 98% across the cycles. Kinetic modeling was performed and a pseudo-second order kinetic model with an R² of 0.981 was obtained implying chemisorption as the rate limiting step. Adsorption equilibrium data for MO were best fitted into the Sips isotherm model which suggests that adsorption occurs on a heterogeneous surface. From the Sips isotherm model, the maximum adsorption capacity was determined to be 1253.44 mg/g, highlighting the viability of CS – MIL-101 (Fe) – PEI beads as an adsorbent for wastewater treatment.

Abstract: Metal-Organic Framework (MOF)-based composite beads consisting of MIL-101(Fe), Chitosan (CS), and Polyethyleneimine (PEI) crosslinked with glutaraldehyde (GLA) were synthesized. Response Surface Methodology was used to optimize the synthesis conditions of the beads to maximize Methyl Orange (MO) removal via batch adsorption experiments. Using an experimental design with three independent variables MIL-101(Fe) (500-1500 ppm), PEI (1-2%), GLA (0.5-2.5%), a second-order polynomial model was obtained to relate MO removal and these variables. A high R² (0.9944) and F-value (176.97) suggested good agreement between experimental data and the model. The optimum beads were found to consist of 500 ppm MIL-101 (Fe), 1.44% PEI, crosslinked in 2.11% GLA corresponding to a percent MO removal of 95.75%. Validation experiments done by subjecting the optimized beads to batch adsorption of MO confirmed good predicting capability of the model with an experimental MO removal of 96.20%. Characterization of the beads was performed using Fourier Transform Infrared Spectroscopy (FTIR) analysis and Scanning Electron Microscope (SEM). The beads were found to contain multiple functional groups and have a coarse surface with a porous structure which are ideal attributes for good adsorbents.the beads was performed using Fourier Transform Infrared Spectroscopy (FTIR) analysis and Scanning Electron Microscope (SEM). The beads were found to contain multiple functional groups and have a coarse surface with a porous structure which are ideal attributes for good adsorbents.

Abstract: Nanomedicine has been used in tumor treatment and research due to its advantages of targeting, controlled release and high absorption rate. Silver nanoparticle (AgNPs), with the advantages of small particle size, and large specific surface area, are of great potential value in suppressing and killing cancer cells. Methods: AgNPs–polyethyleneimine (PEI) –folate (FA) (AgNPs–PF) were synthesised and characterised by several analytical techniques. The ovarian cancer cell line Skov3 was used as the cell model to detect the tumor treatment activity of AgNPs, AgNPs–PF and AgNPs+ AgNPs–PF. Results: Results shown that AgNPs–PF were successfully constructed with uniform particle size of 50–70 nm. AgNPs, AgNPs–PF, AgNPs–PF+ AgNPs all showed a certain ability to inhibit cancer cell proliferation, increase reactive oxygen species and decrease the mitochondrial membrane potential. All AgNPs, AgNPs–PF, AgNPs+ AgNPs–PF promoted DNA damage in Skov3 cells, accompanied by the generation of histone RAD51 and γ-H2AX site, and eventually leading to the apoptosis of Skov3 cells. The combination of AgNPs–PF and AgNPs had a more pronounced effect than either material alone. Conclusion: This study is to report that the combination of AgNPs+ AgNPs–PF can cause stronger cytotoxicity and induce significantly greater cell death compared to AgNPs or AgNPs–PF alone in Skov3 cells. Therefore, the combined application of drugs could be the best way to cancer treatment.

Abstract: Amine-modified solid sorbents have attracted extensive interests in post-combustion carbon capture for power plants. Among various amines, polyethyleneiemine (PEI) is likely to be the most effective and promising candidate. However, previous studies have mainly focused on examining various supports to increase PEI loading and then enhance CO₂ adsorption capacity. In this study, one rare earth element (Ce) and 6 first-row transition metals (from V to Cu) in the oxidation states impregnated on PEI incorporated γ-Al₂O₃ were prepared and investigated as potential catalyst/promotor for base-catalyzed reaction. Thermodynamic analysis, including isothermal and quasi-static CO₂ adsorption tests, were implemented to evaluate the performances amongst the 7 metal oxides. The results showed that MnO₂, CeO₂ and Fe₂O₃ showed a better performance in isothermal CO₂ adsorption at 75°C. Upon quasi-static tests, the results also indicates that the peak adsorption temperatures (T_{peak, a}) of V₂O₅ and Cr₂O₃ shifted to high temperature region, whilst opposite behavior of MnO₂ was observed. In preliminary study, density functional theory (DFT) was also adopted to assist the screening of metal oxide in terms of bond length and adsorption energies.

Abstract: Nanocomposite beads containing 2% chitosan (CS), 2% polyethyleneimine (PEI), and 1,500 ppm graphene oxide (GO) were synthesized for the removal of methyl orange (MO) from water. Characterization of the CS-PEI-GO beads using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) showed favorable adsorbent properties as given by the presence of numerous surface functional groups and a porous structure. Effects of different parameters such as pH, contact time, and initial concentration on the percentage removal of MO and adsorption capacity of the beads were investigated by performing batch adsorption experiments. MO removal of more than 85% was achieved by the beads across a wide pH range. Kinetic studies were performed and a pseudo-second order kinetic equation with R² of 0.9999 was obtained. Furthermore, adsorption equilibrium data for MO were best described by the Toth isotherm model (R² = 0.9644), suggesting multilayer adsorption on heterogeneous adsorption sites with a maximum adsorption capacity of 421.51 mg/g. Finally, FTIR and SEM analyses after adsorption confirmed the presence of MO on the surface of the beads and revealed an intact and stable structure. Overall, the excellent adsorption capability and multi-functionality demonstrated in this study show great potential of the synthesized material for wastewater treatment applications.

Abstract: Bacterial proliferation and biofilm formation has emerged as a significant concern in the long-term use of industrial apparatus. This study describes the antimicrobial properties of a novel chitosan-polyethyleneimine-graphene oxide (CS-PEI-GO) nanocomposite against E. coli. The nanocomposite is a stable material with minimal dispersibility in storage water after more than 7 days. The antimicrobial activity is contact-time-dependent, with direct contact (92% bacterial inactivation after 3h exposure) having superior results compared with dynamic contact (~50% inactivation after 3h exposure). In addition, the incorporation of GO also translated to enhanced production of ROS—oxidation of GSH was higher in CS-PEI-GO (31.78%) as compared to CS-PEI alone (5.69%). This may be attributed to previously proposed mechanisms of mechanical membrane damage and reactive oxygen species production that may be more pronounced with prolonged contact. This may be due to the positively charged chitosan and the negatively charged cell membrane facilitating the coating of cells that could allow the oxygen-containing functional groups of GO to induce oxidative stress and lead to cell death.

Abstract: Functional macromolecule polyethyleneimine (PEI) is grafted onto the surface of silica gel particles with the “graft to” method using γ-chloropropyl trimethoxy silane as coupling agent, and the grafted composite adsorption material PEI/SiO₂ is prepared. The adsorption abilities and mechanism of PEI/SiO₂ towards p-nitrophenol are also studied. The results show that PEI/SiO₂ possesses very strong adsorption ability for p-nitrophenol by hydrogen bond interaction. The adsorption amount can reach to 78.6mg•g⁻¹. The adsorption is physical adsorption of a monomolecular layer and conforms to the Freundlich adsorption model. The pH and temperature have great influence on the adsorption capacity. As sodium hydroxide solution is used as eluent, and the adsorbed phenol is eluted easily from PEI/SiO₂.

Abstract: In this paper, the inhibition efficiency of Quaternary Polyethyleneimine (QPEI) self-adsorbed films was studied by polarization curve and weight loss method. We made an intensive study of its anticorrosion mechanism for low carbon steel in different acid baths using Polyethyleneimine(PEI) and QPEI as inhibitor, respectively. Diatomite particles were surface-modified with PEI and QPEI, respectively, and their zeta potentials were measured. The morphologies and compositions of the polymer film on the steel surface were examined with the aids of SEM and XPS, respectively. Compared with PEI, the cationic property is stronger, and it is not influenced by the PH value of mediums. The zeta potential of diatomite particles surface-modified with QPEI remains higher positive in whole PH range. The above facts enough confirm that anticorrosion mechanism of QPEI for low carbon steel attributes to its possessing outstanding cationic property.

Abstract: Adsorption of soybean oil Silica particles modified by cationic polymer (Polyethyleneimine, PEI) was studied. Zeta potential result shows an increase in positive charge on the surface of modified silica particles. The effects of various parameters on oil adsorption such as PEI concentration, pH, electrolyte concentration, and temperature were investigated. It was found that PEI enhances an adsorption of soybean oil on PEI-modified silica particles. The soybean oil adsorption on the modified silica increased with respect to PEI concentrations. It was revealed that the higher pH, the more soybean oil can be adsorbed on PEI-modified silica surfaces. The electrolyte and high temperature reduces the soybean oil adsorbed on the PEI-modified silica particles.