Hyperbranched Polyethylenimine Research Articles

Polyacrylonitrile fiber functionalized with fluorous hyperbranched polyethylenimine for selective removal of perfluorooctane sulfonate (PFOS) in firefighting wastewaters

Perfluorooctane sulfonate (PFOS) is a well-known persistent organic pollutant in water systems, especially in firefighting wastewaters. It is highly desirable to develop new adsorbents that can remove PFOS efficiently and selectively from firefighting wastewaters. In this work, polyacrylonitrile (PAN) fiber was functionalized by adding fluorous hyperbranched polyethylenimine (F-PEI) under hydrothermal conditions, generating a series of fluorous PAN-g-F-PEI fibers. Compared with the fiber without perfluoroalkyl chains, the existence of perfluoroalkyl chains significantly shortened the equilibrium adsorption time. Lowering solution pH and increasing the F-PEI content were two more efficient ways to improve the maximum equilibrium adsorption capacity. The introduction of enough perfluoroalkyl chains into the fiber effectively suppressed the adverse effect of zwitterionic surfactants, nonionic surfactants and organic solvents on the PFOS removal efficiency, and also alleviated the adverse effect of anionic surfactants. The PAN-g-F-PEI fiber with the largest amount of perfluoroalkyl chains could efficiently and selectively remove PFOS from the firefighting wastewaters containing a high concentration of PFOS and the residual PFOS concentration could reach below 10 ng/L, satisfying the standard of the U.S. Environmental Protection Agency. Moreover, after adsorption, PAN-g-F-PEIs could be easily regenerated by methanol washing and reused for five times without pronounced loss of adsorption capacity.

β-Amyloid Peptide 1-42-Conjugated Magnetic Nanoparticles for the Isolation and Purification of Glycoproteins in Egg White.

Aβ1-42-conjugated magnetic nanoparticles, Aβ1-42@MNP, were prepared by covalently coupling Aβ1-42 to hyperbranched polyethyleneimine (PEI)-modified magnetic nanoparticles via N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC). Aβ1-42's high binding capacity to glycosyl groups facilitates Aβ1-42@MNP composite to be a promising selective adsorbent for glycoproteins in egg whites. In our study, under conditions of pH 4.0, the adsorption efficiency of Aβ1-42@MNP composite for ovalbumin (100 μg mL-1) was 98.4% and its maximum adsorption capacity was 344.8 mg g -1; under the condition of pH 4.0 and 200 mmol L-1 NaCl, its adsorption efficiencies for ovalbumin and ovotransferrin were 96.9% and 60.0%, respectively. According to these primary data, in practice, ovalbumin was removed from egg white by Aβ1-42@MNP composite at pH 4.0 (step I), and then after adding NaCl until the final salt concentration reached 200 mmol L-1 (pretreated egg white), we utilized the same adsorbent to further isolate/purify glycoproteins (step II). SDS-PAGE results showed that Aβ1-42@MNP composite could largely remove ovalbumin in step I and could isolate/purify the remaining ovalbumin and ovotransferrin in step II. LC-MS/MS analysis results showed that the removal of ovalbumin reduced its percentage in egg white samples from 32.93% to 11.05% in step I and the remaining ovalbumin and ovotransferrin were enriched in step II, where the final percentage reached 11.6% and 12.6%, respectively. In summary, 81 protein species were identified after two-step extraction with Aβ1-42@MNP on egg white, while only 46 protein species were identified directly from raw egg white without any pretreatment. This work well illustrates the excellent adsorption performance of Aβ1-42@MNP composite to glycoproteins and its potential in the application of proteomic studies on low-abundance proteins in egg white.

Construction, release and cellular imaging application of triethylamine-responsive fluorescent quantum dots based on supramolecular self-assembly

A new strategy for the construction, release and cellular imaging application of triethylamine-responsive fluorescent quantum dots (QDs) based on supramolecular self-assembly has been described. The supramolecular self-assembly (HPEI/SA), which was constructed through the electrostatic interactions between terminal amine groups of hyperbranched polyethylenimines (HPEI) and carboxylic acid groups of stearic acid (SA), first captured aqueous Zn2+ ions into the hydrophilic dendritic core and subsequently encapsulated QDs/S2- by the complexation interactions and reactions between Zn2+ and S2- on QDs. Due to the pH-responsive property of the HPEI/SA supramolecular self-assembly, the fluorescence of encapsulated QDs is sensitive to the triethylamine/SA mole ratio, and the encapsulated QDs can be released to the aqueous phase by cleaving HPEI/SA. The resulting fluorescent QDs/HPEI nanocomposites show promising prospects in bioimaging.

Concentration-modulated dual-excitation fluorescence of carbon dots used for ratiometric sensing of Fe3+

The development of ratiometric fluorescence sensing platforms with simple synthetic routes and good anti-interference capacities are of great importance for their further application. Herein, hyperbranched polyethylenimine passivated carbon dots (HPEI-CDs) with concentration-modulated dual-excitation fluorescence property were synthesized. At a low concentration, HPEI-CDs only showed one fluorescence center, while at a relatively high concentration, its excitation peak around 355 nm would split into two peaks. Energy level splitting and broadening were demonstrated to be the origin of such dual-excitation behavior. Based on the dual-excitation signals, HPEI-CDs could serve as a ratiometric sensor for the detection of Fe3+ in aqueous solution. The assay exhibited a wide linear response concentration range (2–360 μM) with a limit of detection of 0.47 μM. Significantly, benefiting from the high concentration of HPEI-CDs, the sensor showed good selectivity and excellent anti-interference capacity. In addition, this nanosensor was successfully applied for the detection of Fe3+ in real water samples with satisfactory recoveries.

A fluorescent PET probe based on polyethyleneimine-Ag nanoclusters as a reversible, stable and selective broad-range pH sensor

In this work, nanoclusters (NCs) of Cu and Ag capped with hyperbranched polyethyleneimine (PEI) were prepared using chemical reduction by a one-step hydrothermal method. The PEI coated-NCs were characterized by high-resolution transmission electron microscopy, ζ potential, thermogravimetric analysis, dynamic light scattering, Fourier-transform infrared, UV-visible, and fluorescence spectroscopy. The PEI-NCs exhibited strong absorption and fluorescence, high stability, and excellent water dispersibility. The resulting PEI-NCs showed a reversible and linear response of fluorescence intensity with pH over a wide range (3-11); however, PEI-AgNCs showed a better reversibility and sensitivity than PEI-CuNCs. Unlike several types of pH sensors based on modified NCs, which are based on a nanoparticle aggregation/disaggregation mechanism, the response of our sensor is based on a photoinduced electron transfer process, which gives it a high reversibility. This method was successfully applied in pH measurements in tap water and green tea samples, with excellent results, indicating its practical utility for these applications. A visual device was obtained by immobilizing PEI-AgNCs into agarose hydrogels at different pH values. The results show that the proposed sensor can be used as a pH visual detector. Besides, the light emission of the nanosensor was corroborated by fluorescence microscopy, confirming that the nanosensor based on PEI-AgNCs has great potential to be used in cellular imaging.

Facile passivation of yellow light-emitting CdSe QDs by polyethyleneimine in water to achieve bright white light emission

A bright white light-emitting material based on CdSe QDs was prepared by a facile post-synthetic treatment of passivating the QDs by hyperbranched polyethyleneimine (PEI) in water.

Solvent and catalyst-free modification of hyperbranched polyethyleneimines by ring-opening-addition or ring-opening-polymerization of N-sulfonyl aziridines

Ring-opening (polymerization) of N-sulfonyl aziridines with PEI under solvent/catalyst-free conditions allows the atom-economic synthesis of amphiphilic alkylated PEIs and luminescent PEI-graft-polysulfonamide.

Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context.

Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions. This thin film-format demonstrated good catalytic efficiency (TON up to 3.4 × 103) and stability. Incorporation into a quartz crystal microbalance (QCM) instrument illustrated the potential for using this approach in lab-on-a-chip-based synthesis applications.

A simple and energy-saving route for the fabrication of superhydrophobic surfaces based on modified hyperbranched polyethyleneimine and nano silica

The facile and low-cost fabrication of fluorine-free superhydrophobic surfaces is still a challenge.

Cellulosic fabric treated with hyperbranched polyethyleneimine derivatives for improving antibacterial, dyeing, pH and thermo-responsive performance

Having cotton fabrics with multifunctional properties is of the most research focused on using either different processes or new and different materials. Improving thermo - responsive and antibacterial properties of cotton fabrics decorated with silver nanoparticles and nanogel has been investigated. During this research silver nanoparticles (AgNPs) have been in situ prepared using poly(N-isopropyl acrylamide)/polyethyleneimine microgel. Prepared particles have been characterized, visualized their morphological structure and their particle through microscopic analysis, which proved that their particle size was in range of (6–10 nm). The decorated gel with silver nanoparticles has been functionalized with silicone compounds to produce hybrid material. The produced gel has been characterized for its pH, temperature, textural, rheological, antimicrobial, cytotoxicity, and conductivity properties. The functional properties of the treated and untreated fabrics have been investigated, and the results proved that treated fabric has conductivity, antibacterial, pH and thermo-responsive properties.

Municipal Solid Waste as Secondary Resource: Selectively Separating Cu(II) from Highly Saline Fly Ash Extracts by Polymer-Assisted Ultrafiltration

Urban mining from fly ash resulting from municipal solid waste incineration (MSWI) is becoming more and more important due to the increasing scarcity of supply-critical metals. Metal extraction from acid fly ash leaching has already been established. In this context selective Cu recovery is still a challenge. Therefore, our purpose was the separation of Cu(II) from MSWI fly ash extracts by polymer-assisted ultrafiltration (PAUF). We investigated three polyethyleneimines (PEIs) with regard to metal retention, Cu(II) selectivity, Cu(II) loading capacity, and the viscosity of the PEI containing solutions. A demanding challenge was the highly complex matrix of the fly ash extracts, which contain up to 16 interfering metal ions in high concentrations and a chloride content of 60 g L−1. Overcoming that, Cu(II) was selectively enriched and separated from real fly ash extract at pH 3.0. At pH 1.0, a PEI-free Cu(II) concentrate was obtained and PEIs could be regenerated for reuse in further separation cycles. The PAUF conditions developed at laboratory scale were successfully transferred to pilot scale, and hyperbranched PEI (HB-PEI) was found to be the most suitable reagent for PAUF in a technical scale. Moreover, HB-PEI enables photometric control of the Cu(II) enrichment.

Water vapor dehumidification using thin-film nanocomposite membranes by the in situ formation of ultrasmall size iron-chelated nanoparticles

A facile in situ method by which to incorporate iron oxide nanoparticles (IONPs) entrapped by iron-chelated hyperbranched polyethyleneimine (HPEI) within a polyamide (PA) matrix was successfully applied to form thin film nanocomposite (TFN) membranes. The mechanism of the formation of Fe-HPEI-IONPs and their incorporation into the PA matrix are proposed. The performance of the membranes coated with Fe-HPEI-IONP-TMC combination underwent a mixed water vapor test with N2 gas with different operating parameters. Additionally, the effect of operating time on relative humity and the antibacterial properties were studied. The TFN membranes showed a significant improvement in the membranes Fe-HPEI-IONP content, hydrophilicity, and roughness, providing evidence of their outstanding performance as compared to pristine and thin film composite (TFC) membranes. The best performance of membranes achieved by water vapor/N2 permeation was a water vapor permeance value of 2093 GPU and a water vapor/N2 selectivity value of 1050 at a feed flow rate of 1 L/min and relative humidity of 70% for the M(40) TFN membrane with an iron chloride concentration of 40% with respect to HPEI. Moreover, the M(40) TFN membrane showed excellent anti-biofouling performance as compared to pristine PSf and TFC membranes, likely due to the biocidal effect of IONPs and Fe(III) ions toward E coli.

Graphene Oxide‐Hyperbranched Polyethyleneimine Fabricated and Stabilized AuNPs Nanocomposites for Colorimetric Detection of Silver Ions Based on a Non‐Aggregation Mechanism

AbstractHighly water‐soluble GO‐HPEI was prepared by modifying graphene oxide (GO) with hyperbranched polyethylenimine (HPEI) containing a large number of amines to solve the problem of poor water‐solubility of GO. Using GO‐HPEI as reducing agent and stabilizer, Au nanoparticles (AuNPs) based colorimetric probe (GO‐HPEI/AuNPs) with thermal stability up to 130 °C and high salt resistance was prepared in situ. The morphology and structure of GO‐HPEI/AuNPs were characterized by XPS, FTIR, TEM, DLS and Zeta potential. The GO‐HPEI/AuNPs can detect silver ions (Ag+) through the formation of non‐aggregated and stabilized Au−Ag core‐shell nanoparticles. The unusual sensing mechanism endowed this sensor with unique color variation and high selectivity. The GO‐HPEI/AuNPs sensor exhibited an obvious color change from red to ochre yellow and high sensitivity (LOD=54.9 nM) with a good linear relationship in the range of 0–65.7 μM (R2=0.9903). Furthermore, this colorimetric sensor was successfully applied to detect Ag+ in real water samples. Therefore, the GO‐HPEI/AuNPs sensor based on the formation of new nanomaterials has great potential for detecting Ag+ and analytical applications.

Efficient and Low Cytotoxicity Gene Carriers Based on Amine-Functionalized Polyvinylpyrrolidone.

Non-viral vectors are a safety tool for gene therapy to deliver therapeutic genes. Among the different non-viral vectors, polyvinylpyrrolidone (PVP), a well-known hydrosoluble, neutral, and non-toxic polymer, satisfies the requirements and becomes a suitable candidate for gene delivery. In this study, we describe the preparation of polyvinylpyrrolidones decorated with pyrrolidine, piperidine, and piperazine groups, and evaluate them in vitro as non-viral gene carriers. The properties of these new systems are compared with those of hyperbranched polyethyleneimine (PEI) used as a positive control. Their ability to complex DNA at different N/P molar ratios, from 1:1 up to 10:1, was studied through agarose gel electrophoresis and dynamic light scattering. The resulting complexes (polyplexes) were characterized and evaluated in vitro with murine fibroblast (Swiss 3T3) as non-viral gene carriers, using luciferase as the reporter gene and a calcein cytocompatibility assay. All the copolymers condensed DNA to a particle average size between 100–400 nm when used at N/P ratios of 4:1 or higher. The copolymers with piperidine groups showed higher transfection efficiency than the pyrrolidine and piperazine modified copolymers, and even higher than the positive control of PEI at N/P ratios of 4:1 or higher. All the synthesized polyplexes from an aminated PVP displayed a general tendency of high cytocompatibility (75–95%) in comparison with the positive control PEI (55%).

Incorporation of Core-Shell-Structured Zwitterionic Carbon Dots in Thin-Film Nanocomposite Membranes for Simultaneously Improved Perm-Selectivity and Antifouling Properties.

The development of highly efficient thin-film nanocomposite (TFN) membranes with superior water permeability, maintained rejection performance, and excellent antifouling capacity is critical to meeting the ever-escalating demand for fresh water. Herein, carbon dots (CDs) grafted with hyperbranched zwitterions, denoted as CDs-ZPEI0.6-10k, were first prepared by the hydrothermal treatment of citric acid in the presence of zwitterionic hyperbranched polyethylenimine (ZPEI0.6-10k) with different molecular weights (0.6, 1.8, and 10 kDa). Subsequently, the synthesized nanoparticles were introduced in membrane fabrication to form CDs-ZPEI0.6-10k-embedded TFN (TFN-CDs-ZPEI0.6-10k) membranes. The grafted shells of superhydrophilic ZPEI not only increased the chemical compatibility of CDs in the polyamide layer to suppress the formation of nonselective voids but also created a densely packed network for efficient water transportation and effective divalent salt rejection. The TFN-CDs-ZPEI10k membrane demonstrated a 2.8-fold enhancement in the permeate flux with an increased Na2SO4 rejection rate of 98.1% and improved antifouling properties than the pristine thin-film composite (TFC) membrane. This work provides an insight into the development of functionalized core-shell structured nanoparticles to effectively overcome the permeability-selectivity trade-off limitations and fouling problems in TFC membranes.

Selective adsorption of zwitterionic viscose fiber treated with sodium chloroacetate and hyperbranched polyethylenimine

Anionic modified viscose fiber (AVF) was prepared by using viscose fiber (VF) as raw material, sodium hydroxide as catalyst and sodium chloroacetate as modification reagent. The COOH content of anionic viscose fiber was 109.25 mmol/kg. Anionic viscose fibers were modified with branched polyethylenimine (HPEI) at 140 °C hydrothermal environment using a high-pressure reaction kettle. Zwitterionic viscose fibers (AVF-g-HPEI) with different amino and carboxyl contents could be obtained by changing the ratio of the two modified reagents. Increasing HPEI dosage resulted in amide group content of zwitterionic viscose fibers ranging from 0 to 108.35 mmol/kg. The zwitterionic viscose fibers were characterized by IR, SEM and XPS. IR analysis showed that zwitterionic viscose fiber was successfully prepared. SEM analysis showed that the reaction mainly occurred on the surface of the fiber, and the fiber structure was not changed. XPS analysis demonstrated that with the HPEI dosage increasing nitrogen elements on the surface of zwitterionic viscose fiber increased significantly. Dye adsorption experiments indicated that (1) AVF-g-HPEI could selectively adsorb the anionic dye or the cationic dye (such as methyl orange and methylene blue) from the mixed solution after the pre-treatment with pH 4.5 or pH 10.5 solution, respectively, (2) the dyes adsorbed by zwitterionic viscose fiber could be desorbed in the aqueous solution of pH 4.5 or 10.5, respectively and (3) the desorption ratio of AVF-g-HPEI remained above 0.85 after eight cycles.

Facile Method to Prepare pH-Sensitive PEI-Functionalized Carbon Nanotubes as Rationally Designed Vehicles for Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Delivery

A new pH-sensitive system designed for drug-delivery purposes and based on functionalized multiwall magnetic carbon nanotubes (Mag-CNTs) was synthesized for the effective incorporation of non-steroidal anti-inflammatory drugs (NSAIDs), aiming at drug release in characteristic acidic conditions close to the actual conditions of inflamed tissues. Cationic hyperbranched polyethyleneimine (PEI) was immobilized on the surface of Mag-CNTs via electrostatic interactions between the positively charged protonated amines within the polymer and the carboxyl groups on the chemically oxidized Mag-CNT surface. The addition of the NSAID with a carboxylate donor, Naproxen (NAP), was achieved by indirect coupling through the amino groups of the intermediate linker PEI. FT-IR, Raman, and UV–vis spectroscopy were employed to fully characterize the synthesized nanocarrier and its functionalization procedure. The interaction of the designed nanocarrier with bovine serum albumin (BSA) was studied in vitro by fluorescence emission spectroscopy while its in vitro interaction with calf-thymus (CT) DNA was monitored by UV–vis spectroscopy and viscosity measurements and via competitive studies with ethidium bromide. The calculated binding constants were compared to those of free NAP revealing a higher binding affinity for BSA and CT DNA. Finally, drug-release studies were performed, revealing that the electrostatic linkage ensures an effective release of the drug in the acidic pH typical of inflamed cells, while maintaining the multiwall nanotubes (MWNTs)–drug conjugates stable at the typical bloodstream.

Removal of Cd(II) from Water by HPEI Modified Humin

Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.

Improving the shale stability with nano-silica grafted with hyperbranched polyethyleneimine in water-based drilling fluid

Shale hydration and dispersion leading to wellbore instability is always a challenge in oil and gas drilling engineering. In this study, specifically designed nano-particles by grafting hyperbranched polyethyleneimine (Mw = 600) onto the surface of nano-silica particles were synthesized. The modified nano-particles were characterized with Fourier transform infrared spectrum (FT-IR), particles size distribution measurement, thermal gravimetric analysis (TGA), transmission electron microscope (TEM) and zeta potential measurement. The results indicated that after modification, the nano-particles became positively charged and showed better dispersion in water compared to pristine nano-silica particles. Shale cuttings hot-rolling dispersion test and linear swelling test as chemical inhibitive tests in combination with pressure transmission test and shale sample spontaneous imbibition test as physical plugging tests were used to evaluate the shale stabilizing performance of the modified nano-particles. The results showed that the modified nano-particles exhibited both effective chemical inhibition and physical plugging, whereas nano-silica only showed limited physical plugging. The interaction between modified nano-silica particles and shale demonstrated that the grafted hyperbranched polymer strongly adsorbed onto the clay surface via electrostatic interaction and hydrogen bonding, which resulted in effective inhibition of shale hydration and swelling. After adsorption, the modified nano-silica particles were trapped on the micropores of shale formation and prevented the fluid invasion. The dual functions of the modified nano-silica particles demonstrated a remarkable improvement of shale stability.

The Synthesis and Characterization of Novel Bi-/Trimetallic Nanoparticles and Their Nanocomposite Membranes for Envisaged Water Treatment.

The impact of worldwide water scarcity, further exacerbated by environmental pollution, necessitates the development of effective water treatment membranes. Herein, we report the synthesis and characterization of nanocomposite membranes containing hyperbranched polyethyleneimine (HPEI) stabilized bi-and trimetallic nanoparticles. These membranes were prepared by blending a pre-grafted Polyethersulfone (PES) powder with the Pd@Fe@HPEI and Pd@FeAg@HPEI nanoparticles followed by phase inversion. The membranes, together with stabilized nanoparticles, were characterized by several analytical techniques, such as attenuated total reflectance–Fourier transform infra-red spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), optical contact angle (OCA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HRTEM). These techniques revealed the elemental composition, zerovalent nature of the nanoparticles, and their small and even size distribution. Surface analysis showed chemical bonding between the polymeric functional groups and the supported nanoparticles. Furthermore, the nanocomposite membranes were found to be hydrophilic. Additionally, the membranes were investigated for swelling (water uptake), porosity, pore size, pure water permeation fluxes, and they indicated a decreased protein adhesion property. As such, the membranes fabricated in this work indicate the required properties for application in water treatment.