scholarly journals Grafting of Polypyrrole-3-carboxylic Acid to the Surface of Hexamethylene Diisocyanate-Functionalized Graphene Oxide

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1095 ◽  
Author(s):  
José Antonio Luceño-Sánchez ◽  
Ana Maria Díez-Pascual
Keyword(s):  
Graphene Oxide ◽  
Carboxylic Acid ◽  
Flexible Electronics ◽  
Mechanical Performance ◽  
Ester Group ◽  
Hexamethylene Diisocyanate ◽  
Acyl Chloride ◽  
Functionalized Graphene Oxide ◽  
Modified Graphene Oxide ◽  
Grafting Reactions

A polypyrrole-carboxylic acid derivative (PPy-COOH) was covalently anchored on the surface of hexamethylene diisocyanate (HDI)-modified graphene oxide (GO) following two different esterification approaches: activation of the carboxylic acids of the polymer by carbodiimide, and conversion of the carboxylic groups to acyl chloride. Microscopic observations revealed a decrease in HDI-GO layer thickness for the sample prepared via the first strategy, and the heterogeneous nature of the grafted samples. Infrared and Raman spectroscopies corroborated the grafting success, demonstrating the emergence of a peak associated with the ester group. The yield of the grafting reactions (31% and 42%) was roughly calculated from thermogravimetric analysis, and it was higher for the sample synthesized via formation of the acyl chloride-functionalized PPy. The grafted samples showed higher thermal stability (~30 and 40 °C in the second decomposition stage) and sheet resistance than PPy-COOH. They also exhibited superior stiffness and strength both at 25 and 100 °C, and the reinforcing efficiency was approximately maintained at high temperatures. Improved mechanical performance was attained for the sample with higher grafting yield. The developed method is a valuable approach to covalently attach conductive polymers onto graphenic nanomaterials for application in flexible electronics, fuel cells, solar cells, and supercapacitors.

scholarly journals The Effect of Hexamethylene Diisocyanate-Modified Graphene Oxide as a Nanofiller Material on the Properties of Conductive Polyaniline

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1032 ◽  
Author(s):  
José Antonio Luceño Sánchez ◽  
Ana Maria Díez-Pascual ◽  
Rafael Peña Capilla ◽  
Pilar García Díaz
Keyword(s):  
Graphene Oxide ◽  
Flexible Electronics ◽  
Organic Solar Cells ◽  
High Performance ◽  
In Situ Polymerization ◽  
Low Cost ◽  
Hexamethylene Diisocyanate ◽  
Charge Transfer Complexes ◽  
Modified Graphene Oxide

Conducting polymers like polyaniline (PANI) have gained a lot of interest due to their outstanding electrical and optoelectronic properties combined with their low cost and easy synthesis. To further exploit the performance of PANI, carbon-based nanomaterials like graphene, graphene oxide (GO) and their derivatives can be incorporated in a PANI matrix. In this study, hexamethylene diisocyanate-modified GO (HDI-GO) nanosheets with two different functionalization degrees have been used as nanofillers to develop high-performance PANI/HDI-GO nanocomposites via in situ polymerization of aniline in the presence of HDI-GO followed by ultrasonication and solution casting. The influence of the HDI-GO concentration and functionalization degree on the nanocomposite properties has been examined by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile tests, zeta potential and four-point probe measurements. SEM analysis demonstrated a homogenous dispersion of the HDI-GO nanosheets that were coated by the matrix particles during the in situ polymerization. Raman spectra revealed the existence of very strong PANI-HDI-GO interactions via π-π stacking, H-bonding, and hydrophobic and electrostatic charge-transfer complexes. A steady enhancement in thermal stability and electrical conductivity was found with increasing nanofiller concentration, the improvements being higher with increasing HDI-GO functionalization level. The nanocomposites showed a very good combination of rigidity, strength, ductility and toughness, and the best equilibrium of properties was attained at 5 wt % HDI-GO. The method developed herein opens up a versatile route to prepare multifunctional graphene-based nanocomposites with conductive polymers for a broad range of applications including flexible electronics and organic solar cells.

scholarly journals Preparation of Thin-Film Composite Nanofiltration Membranes Doped with N- and Cl-Functionalized Graphene Oxide for Water Desalination

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1637
Author(s):  
Francisco J. García-Picazo ◽  
Sergio Pérez-Sicairos ◽  
Gustavo A. Fimbres-Weihs ◽  
Shui W. Lin ◽  
Moisés I. Salazar-Gastélum ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Graphene Oxide ◽  
Water Desalination ◽  
Acyl Chloride ◽  
Functionalized Graphene Oxide ◽  
Film Composite ◽  
X Ray ◽  
Thin Film Composite ◽  
Modified Graphene Oxide

In the present work, chemically modified graphene oxide (GO) was incorporated as a crosslinking agent into thin-film composite (TFC) nanofiltration (NF) membranes for water desalination applications, which were prepared by the interfacial polymerization (IP) method, where the monomers were piperazine (PIP) and trimesoyl chloride (TMC). GO was functionalized with monomer-containing groups to promote covalent interactions with the polymeric film. The composite GO/polyamide (PA) was prepared by incorporating amine and acyl chloride groups into the structure of GO and then adding these chemical modified nanomaterial during IP. The effect of functionalized GO on membrane properties and performance was investigated. Chemical composition and surface morphology of the prepared GO and membranes were analyzed by thermogravimetric analysis (TGA), Raman spectroscopy, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The fabricated composite membranes exhibited a significant increase in permeance (from 1.12 to 1.93 L m−2 h−1 bar−1) and salt rejection for Na2SO4 (from 95.9 to 98.9%) and NaCl (from 46.2 to 61.7%) at 2000 ppm, when compared to non-modified membranes. The amine- and acyl chloride-functionalized GO showed improved dispersibility in the respective phase.

scholarly journals High-Performance PEDOT:PSS/Hexamethylene Diisocyanate-Functionalized Graphene Oxide Nanocomposites: Preparation and Properties

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1169 ◽  
Author(s):  
José Luceño Sánchez ◽  
Rafael Peña Capilla ◽  
Ana Díez-Pascual
Keyword(s):  
Graphene Oxide ◽  
Flexible Electronics ◽  
High Performance ◽  
Conductive Polymer ◽  
Tensile Tests ◽  
Sem Analysis ◽  
Hexamethylene Diisocyanate ◽  
Gradual Improvement ◽  
Functionalized Graphene Oxide ◽  
Energy Applications

Graphene oxide (GO) has emerged as an ideal filler to reinforce polymeric matrices owing to its large specific surface area, transparency, flexibility, and very high mechanical strength. Nonetheless, functionalization is required to improve its solubility in common solvents and expand its practical uses. In this work, hexamethylene diisocyanate (HDI)-functionalized GO (HDI-GO) has been used as filler of a conductive polymer matrix, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The nanocomposites have been prepared via a simple solution casting method, and have been characterized by scanning electron microscopy (SEM), UV–Vis and Raman spectroscopies, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile tests, and four-point probe measurements to get information about how the HDI-GO functionalization degree (FD) and the HDI-GO concentration in the nanocomposite influence the final properties. SEM analysis showed a very homogenous dispersion of the HDI-GO nanosheets with the highest FD within the matrix, and the Raman spectra revealed the existence of very strong HDI-GO-PEDOT:PSS interactions. A gradual improvement in thermal stability was found with increasing HDI-GO concentration, with only a small loss in transparency. A reduction in the sheet resistance of PEDOT:PSS was found at low HDI-GO contents, whilst increasing moderately at the highest loading tested. The nanocomposites showed a good combination of stiffness, strength, ductility, and toughness. The optimum balance of properties was attained for samples incorporating 2 and 5 wt % HDI-GO with the highest FD. These solution-processed nanocomposites show considerably improved performance compared to conventional PEDOT:PSS nanocomposites filled with raw GO, and are highly suitable for applications in various fields, including flexible electronics, thermoelectric devices, and solar energy applications.

Doxorubicin Loaded Nanoparticle Consisting of Chitosan and Mannose Modified Graphene Oxide for Intracellular Drug Delivery and Anti-tumor Activity

2020 ◽  
Vol 13 (5) ◽  
pp. 5155-5164
Author(s):  
Meena K. S. ◽  
Sonia K ◽  
Alamelu Bai S
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Drug Delivery System ◽  
Delivery System ◽  
In Vitro Release ◽  
Cancer Drug ◽  
Hemolysis Assay ◽  
Functionalized Graphene Oxide ◽  
Intracellular Drug Delivery ◽  
Modified Graphene Oxide

In order to develop the efficiency and the specificity of anticancer drug delivery, we have designed an innovative nanocarrier. The nanocarrier system comprises of a multifunctional graphene oxide nanoparticle-based drug delivery system (GO-CS-M-DOX) as a novel platform for intracellular drug delivery of doxorubicin (DOX). Firstly, graphene oxide (GO) was synthesized by hummer’s method whose surface was functionalized by chitosan (CS) in order to obtain a more precise drug delivery, the system was then decorated with mannose (M). Further conjugation of an anti-cancer drug doxorubicin to the nanocarrier system resulted in GO-CS-M-DOX drug delivery system. The resultant conjugate was characterized for its physio-chemical properties and its biocompatibility was evaluated via hemolysis assay. The drug entrapment efficiency is as high as 90% and in vitro release studies of DOX under pH 5.3 is significantly higher than that under pH 7.4. The anticancer activity of the synthesized drug delivery system was studied by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay against MCF-7 cell line. These results stated that the pH dependent multifunctional doxorubicin- chitosan functionalized graphene oxide based nanocarrier system, could lead to a promising and potential platform for intracellular delivery and cytotoxicity activity for variety of anticancer drugs.   

A covalently cross-linked reduced functionalized graphene oxide/polyurethane composite based on Diels–Alder chemistry and its potential application in healable flexible electronics

2017 ◽  
Vol 5 (1) ◽  
pp. 220-228 ◽  
Author(s):  
Jinhui Li ◽  
Guoping Zhang ◽  
Rong Sun ◽  
Ching-Ping Wong
Keyword(s):  
Graphene Oxide ◽  
Flexible Electronics ◽  
Potential Application ◽  
High Efficiency ◽  
Diels Alder ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Polyurethane Composite

A novel composite of reduced functionalized graphene oxide/polyurethane based on Diels–Alder chemistry was developed which could be healed microwaves with high efficiency and applied in healable flexible electronics.

scholarly journals Synthesis of hexamethylene diisocyanate-functionalized graphene oxide for solar cell applications

2018 ◽  
Vol 57 ◽  
pp. 02005
Author(s):  
J A Luceño ◽  
A M Díez-Pascual ◽  
R Peña ◽  
P García-Díaz
Keyword(s):  
Graphene Oxide ◽  
Solar Cell ◽  
Conjugated Polymers ◽  
Polymer Solar Cells ◽  
Hexamethylene Diisocyanate ◽  
Functionalized Graphene ◽  
Polar Solvents ◽  
Functionalized Graphene Oxide ◽  
Hydrophobic Nature ◽  
Highly Hydrophobic

Graphene (G), an allotrope of carbon with exceptional optical, electronic, thermal and mechanical properties, and its oxidized form graphene oxide (GO), show huge potential for a broad range of applications. In particular, their high conductivity, transparency, flexibility, and abundance make them suitable for polymer solar cells (PSCs). However, their insolubility in common organic solvents hinders their applications. Consequently, novel functionalization approaches are pursued. The present work is devoted to the preparation of hexamethylene diisocyante-functionalized graphene oxide (HDI-GO). The synthesized nanomaterial shows a highly hydrophobic nature and can be dispersed in organic non-polar solvents, hence is a prospective candidate to be combined with conjugated polymers for solar cell applications.

scholarly journals HDPE/UHMWPE hybrid nanocomposites with surface functionalized graphene oxide towards improved strength and cytocompatibility

2019 ◽  
Vol 16 (150) ◽  
pp. 20180273 ◽  
Author(s):  
Shardul Atul Bhusari ◽  
Vidushi Sharma ◽  
Suryasarathi Bose ◽  
Bikramjit Basu
Keyword(s):  
Graphene Oxide ◽  
Hybrid Approach ◽  
Hybrid Nanocomposites ◽  
Micro Computed Tomography ◽  
Functionalized Graphene Oxide ◽  
Polyethylene Blend ◽  
Uniform Dispersion ◽  
Synthesis Strategy ◽  
Modified Graphene Oxide ◽  
Myoblast Cells

High-density polyethylene (HDPE)-based and ultra-high molecular weight polyethylene (UHMWPE)-based composites with carbonaceous reinforcements are being widely investigated for biomedical applications. The enhancement of material properties critically depends on the nature, amount and compatibility of the reinforcement with the polymeric matrix. To this end, this study demonstrates the efficacy of a ‘dual’ hybrid approach of incorporating modified inorganic nanofiller into an optimized polyethylene blend. In particular, a unique synthesis strategy was adopted to design a covalently bonded maleated polyethylene (mPE) grafted modified graphene oxide (mGO) hybrid nanocomposite. In this scheme, polyethyleneimine (PEI) was initially attached onto GO to synthesize amine functionalized GO (GO–PEI). This is followed by mPE grafting, resulting in mGO. Melt-extrusion together with injection moulding of a polymer mix (60% HDPE–40% UHMWPE) with different proportions (less than or equal to 3 wt%) of surface functionalized GO was conducted to develop nanocomposites of different sizes and shapes. When compared with unreinforced PE blend, the nanocomposites with 1 wt% mGO exhibited an increase in ultimate tensile strength by 120% (up to 65 MPa) and elastic modulus by 40% (up to 908 MPa). The uniform dispersion of modified GO nanofillers, confirmed using X-ray micro-computed tomography and transmission electron microscopy, facilitated effective interfacial adhesion and compatibility with the hybrid polymer matrix. The variation in mechanical properties with GO/mGO addition to PE blend was critically discussed in reference to the structural modification of GO, crystallinity and nature of dispersion of fillers. Importantly, the nanocomposites support the attachment and proliferation of C2C12 murine myoblast cells over 3 days in culture in a statistically insignificant manner with respect to polymer blends without any nanofiller. Taken together, the experimental results suggest that HDPE/UHMWPE/mGO is a promising biomaterial for bone tissue engineering applications.

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