Graphene Oxide Nanocomposite Hydrogels Research Articles

An Ammonia Gas Sensor Based on Reduced Graphene Oxide Nanocomposite Hydrogels

AbstractA flexible gas sensor based on nanocomposite has been developed and characterized for detecting ammonia gas (NH3) in the atmosphere. This sensor utilizes nanocomposite hydrogels composed of Arabic gum (AG), acrylic acid (AAc), reduced graphene oxide (RGO), and silver nanoparticles (AgNPs). Various techniques, including FTIR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy), XRD (X‐ray Diffraction), SEM (Scanning Electron Microscopy), XRF (X‐ray Fluorescence), TGA (Thermo‐gravimetric Analysis), DSC (Differential Scanning Calorimetry), were used to evaluate the sensor‘s properties. The nanocomposite hydrogels showed exceptional swelling ability (597 %), advantageous for accommodating gas molecules like NH3. The Polymerization and network formation percentages of 31 % and 56 %, respectively, suggest a robust hydrogel matrix structure. When tested for NH3 gas sensing at room temperature, the RGO/AgNPs/AGPAAc‐hydrogel exhibited high sensitivity and stability compared to other variants across gas concentrations ranging from 0 to 100 ppm. The improved performance of the physiochemical properties of the nanocomposite hydrogels might be attributed to the combined effect of AgNPs and RGO, which likely enhance sensitivity and stability. Selectivity tests conducted for three gases at room temperature revealed that the sensor response was highly selective to NH3 at a concentration of 50 ppm. Furthermore, the sensor demonstrated consistent performance over time. These findings suggest potential applications in environmental monitoring and industrial safety, with the possibility of contributing to advancements in gas sensing technology and addressing environmental and safety concerns.

Novel microbicide graphene oxide nanocomposite hydrogel against herpes simplex virus

Hydrogels are 3D network soft materials capable of swelling in water. Graphene oxide (GO) hydrogels have garnered attention due to their inherent biocompatibility, large surface area, bioavailability, and excellent mechanical properties. In this study, we report the synthesis and characterization of a novel hydrogel nanocomposite incorporating GO, chitosan nanoparticles (CS NPs), zinc oxide nanoparticles (ZnO NPs), and tannic acid (TA). TA acts as a green crosslinker for GO, a binder for ZnO NPs, and a material known for its antiviral and antimicrobial activity. GO sheets were used to stabilize ZnO NPs and prevent their agglomeration. We evaluated the antimicrobial and antiviral activity of the novel nanocomposite hydrogel against pathogenic microbes and the herpes simplex virus (HSV-1), which revealed strong inhibition effects.We demonstrated that the hydrogel nanocomposite incorporating TA, CS NPs,ZnO NPs, and GO sheets displays novel antimicrobial properties. The hydrogel nanocomposite presents a versatile framework for the integration of antibacterial activity against Gram-positive and Gram-negative bacteria, as well as antifungal and anti-Herpes virus (HSV-1) applications. Furthermore, this hydrogel exhibited superior antiviral activity against the HSV-1 virus, with nearly 86% inhibition. The hydrogels possess pH-responsive properties with no cytotoxic effects and represent an up-to-date strategy for improving antiviral surfaces, personal protective equipment (PPE), and sprays based on their excellent swelling properties.

Graphene Oxide Nanocomposite Hydrogels Based on Mucilage Extracted from Ocimum basilicum Seeds Grafted by Acrylate Polymers; Assay on Physicochemical Properties

Graphene Oxide Nanocomposite Hydrogels Based on Mucilage Extracted from Ocimum basilicum Seeds Grafted by Acrylate Polymers; Assay on Physicochemical Properties

Phosphonated graphene oxide-modified polyacrylamide hydrogel electrolytes for solid-state zinc-ion batteries

Compared to rigid batteries using liquid electrolytes, solid-state batteries (SSBs) offer several advantages: flexibility, prevention of leakage, suppression of dendritic formation and hydrogen evolution, as well as minimization of cathode active material dissolution. For the materialization of real-life SSBs, gel polymer electrolytes (GPEs) are among promising candidates. However, development of GPEs with satisfying ionic conductivity and mechanical endurance is challenging. Herein, we report on the development of polyacrylamide (PAM)/phosphonated graphene oxide (PGO) nanocomposite hydrogel electrolytes for zinc-ion batteries; PGO acts as the filler through in-situ polymerization of acrylamide in an aqueous suspension of PGO. The synthesized PAM/PGO hydrogel exhibits high ionic conductivity of 31.0 mS/cm at 30 °C compared to that of PAM (13.8 mS/cm) and PAM-GO (20.8 mS/cm). The higher ionic conductivity of PAM-PGO can be attributed to its higher hydrophilicity and electrolyte storage capacity along with its lower activation energy for ionic conduction (7.2 KJ/mol K) in comparison with that of PAM (10.1 KJ/mol K) and PAM-GO (10.2 KJ/mol K). The interaction between water against PAM, PAM-GO and PAM-PGO is investigated via density-functional theory (DFT). The MnO2-based zinc-ion battery assembled using PAM-PGO as electrolyte shows high initial capacity of 240 mAh/g, losing only 4 and 15% of its capacity after 100 and 145 cycles, respectively. Results demonstrate promising potential of PAM-PGO as a solid-state electrolyte for flexible battery applications.

Synthesis, characterization, and rheological behavior of HPG graft poly (AM-co-AMPS)/GO nanocomposite hydrogel system for enhanced oil recovery

The purpose of this study is to investigate the synthesis of graft copolymer nanocomposite based on hydroxypropyl guar (HPG) graft acrylamide (AM) and 2-acryloamido-2-methyl propane sulfonic acid (AMPS), reinforced with graphene oxide (GO), and study its suitability for the development of the copolymer-based hydrogel systems by chromium triacetate crosslinker to use in oil recovery applications. The characterization outcomes acknowledged the grafting of AM and AMPS onto HPG in the attendance of the GO. The uniform dispersion of GO at 0.1 wt.% was observed in the morphology analysis. Moreover, not only the viscosity but also, the storage and loss modulus of graft copolymer nanocomposites hydrogel improved by adding GO. The effect of graft copolymer nanocomposite and crosslinker concentrations on the performance of hydrogel was also evaluated and optimized by a rheological test. These results showed the outstanding performance of crosslinked hydrogel structure of HPG-g-poly (AM-co-AMPS)/GO, owing to the linking of AM with AMPS and grafting on the HPG chains and the surface of GO in attendance of chromium triacetate. This makes the copolymer hydrogel system more stable against salinity, shearing, and high temperatures. Therefore, this nanocomposite hydrogel system is potentially useful for oil recovery applications.

Super-strong and anti-tearing poly(vinyl alcohol)/graphene oxide nano-composite hydrogels fabricated by formation of multiple crosslinking bonding network structure

As load-bearing material in biomedical-applications as cartilage replacement, artificial meniscus and tendons, etc., poly(vinyl alcohol) (PVA)/graphene oxide (GO)-tannic acid (TA) nano-composite hydrogels with multiple-crosslinking network were fabricated by establishing freezing/thawing-annealing-swelling method. By TA anchoring, PVA molecules were grafted onto GO surface efficiently, and strong interfacial interaction led to exfoliation and uniform distribution of GO in matrix. By introducing annealing process, the crystallinity and crystallite size of PVA increased and introducing GO-TA led to more perfect and denser crystalline structure, while physical crosslinking network centered on GO-TA and hydrogen bond-abundant crystalline phase formed, resulting in increasing crosslinking density of hydrogel. By further swelling in CaCl2 aqueous solution, hydroxyl-Ca2+ coordination formed, and multiple-crosslinking network was constructed with high crosslinking density. The tensile strength and fracture toughness of composite hydrogel were remarkably improved, reaching 14.38 MPa/27.93 MJ/m3, approximately 11-/26-fold higher than those of neat PVA hydrogel, while tearing strength was significantly enhanced, attributed to high energy dissipation through unzipping multiple interactions.

Characterization of a Multi-responsive Magnetic Graphene Oxide Nanocomposite Hydrogel and Its Application for DOX Delivery

Nanocomposite hydrogels are one of the most important types of biomaterials which can be used in many different applications such as drug delivery and tissue engineering. Placement of nanoparticles within a hydrogel matrix can provide unique characteristics like remote stimulate and mechanical strength improvement. In this study, the synthesis of graphene oxide and graphene oxide nanocomposite hydrogel has been studied. Nanocomposite hydrogel was synthesized with carboxymethyl cellulose as a natural base, acrylic acid as a monomer, graphene oxide as a filler, ammonium persulfate as an initiator, and iron nanoparticles as a crosslinking agent. The effect of reaction variables such as the iron nanoparticles, graphene oxide, ammonium persulfate, and acrylic acid were examined to achieve a hydrogel with maximum absorbency. Doxorubicin, as an anti-cancer chemotherapy drug, was loaded on this hydrogel and the release of drug in a phosphate buffer solution with different pH was carried out. The structure of the graphene oxide and optimized hydrogel were confirmed by Fourier-transform infrared spectroscopy, Raman spectroscopy, X-Ray diffraction, scanning electron microscopy, and atomic force microscopy.

Fabrication of chitosan-aminopropylsilane graphene oxide nanocomposite hydrogel embedded PES membrane for improved filtration performance and lead separation

In the present study chitosan-aminopropylsilane graphene oxide (CS-APSGO) nanocomposite hydrogel was synthesized and utilized as a hydrophilic additive in different dosages (0.5, 1, 2 and 5 wt%) in fabrication of porous polyethersulfone (PES) membranes via the phase inversion induced process by immersion precipitation method for heavy metal ion and dye removal. The modified membranes were characterized using ATR-FTIR, AFM, SEM, water contact angle, overall porosity and mean pore radius evaluations and zeta potential measurement. The addition of CS-APSGO nanocomposite hydrogel to PES doping solutions enhanced membranes hydrophilicity and consequently pure water flux permeability. Filtration performance of the CS-APSGO embedded membranes showed promising antifouling properties during BSA filtration test (FRR> 90%) and 1 wt% membranes showed the highest pure water flux of 123.8 L/m2 h with BSA rejection more than 98% and removal capability more than 82% for lead (II) ion, 90.5% and 98.5% for C.I. Reactive Blue 50 and C.I. Reactive Green 19, respectively. Therefore, the CS-APSGO nanocomposite hydrogel blending in order to modification of PES-based membranes have a noticeable potential in improving filtration performance of blended membranes.

Collagen/chitosan-functionalized graphene oxide hydrogel provide a 3D matrix for neural stem/precursor cells survival, adhesion, infiltration and migration

To have therapeutic promise of neural stem/precursor cells (NS/PCs) an appropriate scaffold is mostly essential. This study was conducted to fabricate collagen (Col)/chitosan-functionalized graphene oxide (CSGO) nanocomposite hydrogel and evaluated it as scaffold for NS/PCs. Graphene oxide was first functionalized with chitosan and the obtained CSGO was then added to Col solution and the solution underwent hydrogel formation. GO sheets were exfoliated after CS functionalization and the CSGO was homogenously dispersed in Col hydrogel. CSGO addition resulted in hydrogels with higher porosity and smaller Col fibers. Furthermore, CSGO increased the gelation time and water absorption capacity while the degradation was decreased. Cell studies demonstrated higher viability of NS/PCs on Col/CSGO hydrogel comparing with Col and poly-l-lysine as control (Cnt). NS/PCs were also penetrated into the Col/CSGO hydrogel and showed more cell spreading, neurite outgrowth and inter-cell connections in comparison with Col hydrogel. In addition, the cells traveled longer distance on Col/CSGO hydrogels than on Col and Cnt, indicating excellent migration capacity of NS/PCs on Col/CSGO hydrogel. Our results indicate the potential Col/CSGO hydrogels as an appropriate scaffold for NS/PCs.

Rheology and direct write printing of chitosan - graphene oxide nanocomposite hydrogels for differentiation of neuroblastoma cells

The direct write printing method has gained popularity in synthesizing scaffolds for tissue engineering. To achieve an excellent printability of scaffolds, a thorough evaluation of rheological properties is required. We report the synthesis, characterization, rheology, and direct-write printing of chitosan - graphene oxide (CH - GO) nanocomposite hydrogels at a varying concentration of GO in 3 and 4 wt% CH polymeric gels. Rheological characterization of CH - GO hydrogels shows that an addition of only 0.5 wt% of GO leads to a substantial increase in storage modulus (G′), viscosity, and yield stress of 3 and 4 wt% of CH hydrogels. A three-interval thixotropy test (3ITT) shows that 3 wt% CH with 0.5 wt% GO hydrogel has 94% recovery of G′ after 7 sequential stress cycles and is the best candidate for direct-write printing. Neuronal cell culture on 3 wt% CH with 0.5 wt% hydrogels reveals that GO promotes the differentiation of SH-SY5Y cells.

Poly(vinyl alcohol)/graphene oxide nanocomposite hydrogel with catalytic activity: the removal behavior and dual adsorption/catalytic degradation mechanism for dye wastewater

AbstractThe treatment of dye wastewater with traditional adsorption materials usually proceeds slowly with low removal efficiency and without completely eliminating dye molecules, leading to secondary pollution. In this work, poly(vinyl alcohol)/graphene oxide@tetraamino iron phthalocyanine (PVA/GO@TAFePc) nanocomposite hydrogels with catalytic activity were prepared via an in situ crosslinking method. Through interfacial covalent and π–π interactions, TAFePc was loaded onto GO layers with a high loading ratio, and GO@TAFePc was exfoliated and uniformly dispersed in the matrix. With increasing GO@TAFePc hybrid content, the pore size increased and a loose network structure was formed for the hydrogels, while the specific surface area rose significantly by using the hydrogel in a dye removal process, the removal rate of methylene blue (MB) increased sharply with contact time, reaching 98% in the presence of H2O2 with good reusability, and high removal efficiency was achieved for different dyes. The large surface area of the hydrogel was beneficial for MB adsorption. Meanwhile, under catalysis of TAFePc, a large amount of high activity ·OH was produced by H2O2 so as to degrade the MB molecules rapidly. Therefore, the MB degradation process for the composite hydrogel was ascribed to a dual adsorption/catalytic degradation mechanism. © 2020 Society of Industrial Chemistry

Effect of graphene oxide content on the tensile properties and swelling ratio of chitosan/xanthan gum/graphene oxide hydrogel films

In this study, chitosan (CS)/xanthan gum (XA)/graphene oxide (GO) nanocomposite hydrogels were prepared to enhance mechanical properties of CS/XA hydrogels. The hydrogels were characterized by Fourier-transform infrared spectroscopy (FT-IR) spectra, wide-angle X-ray diffraction (WXAD) patterns, thermogravimetric analysis, and universal testing machine. The swelling ratio of dried CS/XA and CS/XA/GO films were also measured in deionized water at 37 °C. The effect of GO content on the tensile properties and swelling ratio of CS/XA/GO hydrogel films were investigated. With addition of GO, tensile strength and modulus of CS/XA hydrogel films were improved without significant decrease of elongation at break, while the swelling ratio of CS/XA/GO films decreased with increasing GO contents.

Biocompatible double network poly(acrylamide-co-acrylic acid)–Al3+/poly(vinyl alcohol)/graphene oxide nanocomposite hydrogels with excellent mechanical properties, self-recovery and self-healing ability

Biocompatible double network PAmAA–Al3+/PVA/GO nanocomposite hydrogels based on non-covalent interactions were synthesized, and the non-covalent interactions endow the materials with good self-recovery and self-healing performances.

Fabrication of Photothermally Responsive Nanocomposite Hydrogel through 3D Printing

AbstractThe responsive hydrogels have received great attention in many fields. However, the molding method and response mode of such hydrogels are criticized when it comes to real applications. In this work, a novel class of poly(N‐isopropyl acrylamide)/graphene oxide (PNIPAm/GO) nanocomposite hydrogel through self‐assembly three‐dimensional (3D) printing via ultraviolet light polymerization. The precursor is ordinarily constituted by NIPAm monomer, crosslinker, and water mixed with a photoinitiator, besides the introduction of nanoclay adjusts the shear thinning properties to an optimal level, which is important for the 3D printing precision. Then, the graphite oxide as infrared light absorber endows the hydrogel fast photothermal excited responsivity instead of conventional temperature response. The shrinkage and swelling of the composite hydrogel can be controlled by turning the near‐infrared light on or off. Meanwhile, the reversible behavior of as‐prepared hydrogel is easily regulated by altering the content of GO and illumination time of near‐infrared light. Additionally, a round tube is obtained based on the as‐prepared hydrogel, which can be driven to get a pencil, indicating their potential applications in actuator and other functional program.

Graphene Oxide Nanocomposite Hydrogel Beads for Removal of Selenium in Contaminated Water

Selenium in water is becoming of increasing risk to human exposure because only recently serious health effects have been associated with their presence in water resources. The present study invest...

Construction of Dual Orientation Crystalline Structure in Poly(vinyl alcohol)/Graphene Oxide Nano-Composite Hydrogels and Reinforcing Mechanism

Oriented poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposite hydrogels with different draw ratios were prepared by stretching during a freezing/thawing process. The PVA/GO samples with a draw ratio of 200% had significantly enhanced mechanical properties by formation of a microfibrillar structure, while the tensile strength and compressive modulus respectively reached as high as 11.60 and 4.05 MPa, outperforming the unoriented samples with an increase of 167% and 540%, respectively. During the freezing/thawing process under stress, the orientation factor, crystallinity, and cross-linking density (υe) of PVA/GO samples increased steadily, while the regularly arranged fibrillar bundle structure increasingly formed, and the size of the porous structure decreased. Besides that, additional PVA crystals formed with decreasing long period (L), crystalline region (Lc), and lamellae size (Llateral). Due to the synergic orientation of GO sheets and nucleation effect, the oriented PVA/GO samples showed an or...

Preparation of Xylan-g-/P(AA-co-AM)/GO Nanocomposite Hydrogel and its Adsorption for Heavy Metal Ions.

Xylan-g-/P(AA-co-AM)/Graphene oxide (GO) hydrogels were prepared and used in the removal of heavy mental ions. Acrylamide (AM), acrylic acid (AA), and xylan were used as the raw materials to prepare the hydrogels with ammonium persulfate (APS) as the initiator. The prepared hydrogels were characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and energy dispersive X-ray (EDX). Some important properties of nanocomposite hydrogels such as swelling behavior, mechanical property, and adsorption capacity were also examined as well as the regeneration of the hydrogels. The results showed that the prepared hydrogels reached the equilibrium state of swelling after 12 h, and the compressive strength of the hydrogel with 30 mg of GO could reach up to 203 kPa. Compared with traditional hydrogel, the mechanical properties of the hydrogels with GO were obviously improved. The maximum adsorption capacity of hydrogels for Pb2+, Cd2+, and Zn2+ could reach up to 683 mg/g, 281 mg/g, and 135 mg/g, respectively. After five cycles of adsorption and desorption, the recovery rate of the hydrogels on Pb2+, Cd2+, and Zn2+ was still up to 87%, 80%, and 80%, respectively—all above 80%.

Graphene oxide nanocomposite hydrogel based on poly(acrylic acid) grafted onto salep: an adsorbent for the removal of noxious dyes from water

In this study, a graphene oxide nanocomposite hydrogel (GONH) based on poly(acrylic acid) grafted onto a natural salep polysaccharide was synthesized and investigated as an adsorbent for the removal of cationic dye from aqueous solution.

Poly (vinyl alcohol)/graphene oxide nanocomposite films and hydrogels prepared by gamma ray

ABSTRACTPoly (vinyl alcohol)/graphene oxide (PVA/GO) gamma irradiated nanocomposite films and hydrogels were prepared. In composite films, GO was initially irradiated by gamma ray in order to improve interactions between GO and PVA. The film containing 1 wt-% GO was very strong where tensile modulus and tensile yield strength were 45 and 115% higher than those of pure PVA. In the second set of experiments PVA/GO hydrogels were made by irradiating PVA/GO suspensions by gamma ray at various doses. It was an interesting finding that GO increased the gel portion of hydrogels through contribution of H-bonds between PVA and GO. The hydrogels prepared at 20 kGy had remarkable water swelling ratio that reached as high as 20 at water temperature of 80°C. The hydrogel metal ion adsorption capability was tested on Cu2+ ions. It was shown that the GO contributed significantly to the adsorption capacity of PVA hydrogels.

Carboxymethylcellulose-quaternary graphene oxide nanocomposite polymer hydrogel as a biodegradable draw agent for osmotic water treatment process

Forward osmosis (FO) as a membrane-based water treatment process, utilizes the natural osmotic pressure gradient as driving force, originates from two solutions with different concentrations separated by a semipermeable membrane. Eligible FO draw agents of low cost, high water flux, easy recovery, and low reverse draw solute flux play a key role in the FO process. Some recently developed polymer hydrogels showed attractive features as draw agents in the FO process. In this study, a biocompatible and biodegradable polymer hydrogel was synthesized via free radical polymerization of the carboxymethylcellulose and acrylic acid as biocompatible monomers and subsequently used as an FO draw agent. In addition, to enhance the FO performance of polymer hydrogel, quaternary graphene oxide (QGO) as nanomodifier was synthesized and incorporated within the hydrogel matrix. The successful incorporation of QGO and its effect on FO performance of the hydrogel was systematically investigated. The obtained results showed that the QGO modified hydrogels have higher swelling ratio than the pure polymer hydrogel due to their more polar functional groups and more porous structures. The QGO hydrogel also has significantly higher water flux than the pure polymer hydrogel.