Polymer grafting on graphene layers by controlled radical polymerization

Eskandari, Parvaneh; Abousalman-Rezvani, Zahra; Roghani‐Mamaqani, Hossein; Salami‐Kalajahi, Mehdi; Mardani, Hanieh

doi:10.1016/j.cis.2019.102021

Cited by 74 publications

(33 citation statements)

References 199 publications

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“…Chitosan has a highly regular structure consisting of β -(1→4) linked D-glucosamine repeating units with three reactive groups, giving many possibilities of functionalization. Among the various methods, graft modification is considered as a convenient and promising approach to expand the applicability and functionality of chitosan [2,3,4,5,6,7,8]. However, the conventional grafting techniques on chitosan do not give control on the side polymer chain lengths and composition, the number of grafting sites, and grafting percentage.…”

Section: Introductionmentioning

confidence: 99%

Chitosan-Graft-Poly(N-Isopropylacrylamide)/PVA Cryogels as Carriers for Mucosal Delivery of Voriconazole

et al. 2019

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The objective of this study was to prepare and characterize physically crosslinked gel formulations of chitosan (CS)-graft-poly(N-isopropyl acrylamide) (PNIPAAm) and polyvinyl alcohol (PVA) for smart delivery of an antifungal drug, Voriconazole, for mucosal applications. For this purpose, cryogels of CS-g-PNIPAAm/PVA and CS/PVA were tested by means of texture profile analysis and rheology to determine optimal matrix properties for topical application. The ratio of 75/25 v/v % CS-g-PNIPAAm/PVA was selected to be used for formulation since it gave low compressibility and hardness (1.2 and 0.6 N) as well as high adhesion properties and non-Newtonian flow behavior. The cryogels and formulations were further characterized by means of FTIR spectroscopy, swelling behavior, texture analysis, scanning electron microscopy (SEM), thermal (differential scanning calorimetry (DSC) and TGA), and rheological behavior. The drug loading capacity and in vitro release profile of the drug, storage stability, and cytotoxicity tests were also performed for the gel formulation. The FTIR, DSC, and TGA results verified the successful formation of cryogels. Swelling studies revealed a pH-dependent swelling ability with a maximum swelling degree of 1200% in acid and 990% in phosphate buffer (pH = 7.4). Thermal studies showed that CS-g-PNIPAAm/PVA 75/25 had higher thermal stability proving the structural complexity of the polymer. The loading capacity of Voriconazole was found to be 70% (w/w). The in vitro release profiles of Voriconazole showed Fickian release behavior for CS-g-PNIPAAm/PVA 75/25 gel with an approximate delivery of 38% within 8 h, slower than matrices containing unmodified chitosan. The storage stability test exhibited that the gel formulation was still stable even after aging for two months. Moreover, the cell culture assays revealed a non-toxic character of the polymeric matrix. Overall results showed that the CS-g-PNIPAAm/PVA 75/25 hydrogel has the potential to be used as a smart polymeric vehicle for topical applications.

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Section: Introductionmentioning

confidence: 99%

Chitosan-Graft-Poly(N-Isopropylacrylamide)/PVA Cryogels as Carriers for Mucosal Delivery of Voriconazole

et al. 2019

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“…Grafting of polymeric chains onto G nanosheets can be carried out via "grafting-to", "grafting-from", and "grafting-through" approaches (Figure 2) [145]. The first consists of synthetizing G and polymers individually and connecting them.…”

Section: Graphene Functionalization Approachesmentioning

confidence: 99%

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Sainz-Urruela

Vera

Andrés

et al. 2021

IJMS

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Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.

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“…Oxidized graphene layers possess enormous oxygen containing functional groups, such as epoxide, hydroxyl, carboxyl, and carbonyl groups at the edge or surface [27] . Theses oxygen functionalities make it possible to simply exfoliate and disperse the layers in a polymer matrix after its further chemical functionalization [28–30] . S. K. Yadav et al .…”

Section: Introductionmentioning

confidence: 99%

Hyperbranched Poly(amidoamine)‐Grafted Graphene Oxide as a Multifunctional Curing Agent for Epoxy‐Terminated Polyurethane Composites

et al. 2021

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Graphene oxide (GO) modified with hyperbranched poly(amidoamine) (PAMAM) structure (GOD) was used as a multifunctional curing agent in the preparation of thermally stable composites from epoxy‐terminated polyurethanes. The multifunctional GOD sample was prepared through a divergent approach by using (3‐Aminopropyl)triethoxysilane (APTES)‐functionalized GO as the core for grafting PAMAM dendrimer by sequential addition of methyl acrylate and ethylenediamine (EDA). Epoxy‐terminated polyurethanes with two different chain extenders of 1,4‐butanediol (BD) and pyromellitic dianhydride (PMDA) were prepared from the reaction of poly(ethylene glycol), hexamethylene diisocyanate, and chain extenders, and subsequent end group transformation of the isocyanate to epoxy functionalities. Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA) proved successful preparation of GOD. TGA indicated improvement in char content and thermal stabilities of the composites with increasing GOD content and using the PMDA chain extender in comparison with the BD. Weight percentages of APTES, methyl acrylate, and EDA in the modified graphene samples were 15.8, 2.2, and 2.2 wt %, respectively, in each of the successive modification process of GO. Structural study of the graphitic and hybrid samples was accomplished with X‐ray diffraction and electron microscopies. A broad peak at about 21° in the patterns of hybrid composites originates from the amorphous structure of polyurethane.

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Polymer grafting on graphene layers by controlled radical polymerization

Cited by 74 publications

References 199 publications

Chitosan-Graft-Poly(N-Isopropylacrylamide)/PVA Cryogels as Carriers for Mucosal Delivery of Voriconazole

Chitosan-Graft-Poly(N-Isopropylacrylamide)/PVA Cryogels as Carriers for Mucosal Delivery of Voriconazole

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Hyperbranched Poly(amidoamine)‐Grafted Graphene Oxide as a Multifunctional Curing Agent for Epoxy‐Terminated Polyurethane Composites

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