Optical Properties of Composites Based on Graphene Oxide and Polystyrene

In this work, new optical properties of composites based on polystyrene (PS) microspheres and graphene oxide (GO) are reported. The radical polymerization of styrene in the presence of benzoyl peroxide, pentane and GO induces the appearance of new ester groups in the PS macromolecular chains remarked through an increase in the absorbance of the infrared (IR) band at 1743 cm−1. The decrease in the GO concentration in the PS/GO composites mass from 5 wt.% to 0.5 wt.% induces a diminution in the intensities of the D and G Raman bands of GO simultaneous with a down-shift of the D band from 1351 to 1322 cm−1. These variations correlated with the covalent functionalization of the GO layers with PS. For the first time, the photoluminescent (PL) properties of PS/GO composites are reported. The PS microspheres are characterized by a PL band at 397 nm. Through increasing the GO sheets’ concentration in the PS/GO composite mass from 0.5 wt.% to 5 wt.%, a PS PL quenching process is reported. In addition, in the presence of ultraviolet A (UVA) light, a photo-degradation process of the PS/GO composite having the GO concentration equal to 5 wt.% is demonstrated by the PL studies.

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Optical Properties of Composites Based on Poly (o-phenylenediamine), Poly (Vinylenefluoride) and Double-Wall Carbon Nanotubes

International Journal of Molecular Sciences ◽

10.3390/ijms22158260 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8260

Author(s):

Mihaela Baibarac ◽

Monica Daescu ◽

Elena Matei ◽

Daniela Nastac ◽

Oana Cramariuc

Keyword(s):

Carbon Nanotubes ◽

Optical Properties ◽

Vinylidene Fluoride ◽

Polymerization Reaction ◽

Covalent Functionalization ◽

Quenching Process ◽

Poly Vinylidene Fluoride ◽

Double Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Pl Quenching

In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm−1 to 1415 cm−1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm−1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL) quenching process. An additional PL quenching process of the POPD-PVDF blends is reported to be induced in the presence of DWNTs. The studies of anisotropic PL highlight a change of the angle of the binding of the PVDF spheres onto the POPD fiber like structures surface from 50.2° to 38° when the carbon nanotubes concentration increases in the POPD-PVDF/DWNTs composites mass up to 2 wt.%.

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Poly(Vinyl Chloride) Spheres Coated with Graphene Oxide Sheets: From Synthesis to Optical Properties and Their Applications as Flame-Retardant Agents

Polymers ◽

10.3390/polym13040565 ◽

2021 ◽

Vol 13 (4) ◽

pp. 565 ◽

Cited By ~ 1

Author(s):

Mihaela Baibarac ◽

Luiza Stingescu ◽

Malvina Stroe ◽

Catalin Negrila ◽

Elena Matei ◽

...

Keyword(s):

Graphene Oxide ◽

Flame Retardant ◽

Vinyl Chloride ◽

Ethyl Cellulose ◽

Lauroyl Peroxide ◽

Poly Vinyl Chloride ◽

Quenching Process ◽

Pl Quenching ◽

Graphene Oxide Sheets ◽

Scanning Electron

A new method to obtain poly(vinyl chloride) (PVC) spheres, which consists of an interaction between commercial PVC grains and hexyl ethyl cellulose and lauroyl peroxide at a temperature of 60 °C, is reported. The addition of the graphene oxide (GO) sheets dispersed in dimethylformamide to the reaction mixture leads to the generation of composites made of PVC spheres coated with GO sheets. Scanning electron microscopy studies have demonstrated that this method allows for the transformation of PVC grains with sizes between 75 and 227 μm into spheres with sizes varying from 0.7 to 3.5 μm when the GO concentration in the PVC/GO composite mass increases from 0.5 to 5 wt.%. Our studies of Raman scattering and FTIR spectroscopy highlight a series of changes that indicate the appearance of ClCH=CH–, CH2=CCl–, and/or –CH=CCl– units as a result of PVC partial dehydrogenation. New –COO– and C–OH bonds on the GO sheet surfaces are induced during the preparation of PVC spheres coated with GO sheets. A photoluminescence (PL) band with a maximum at 325 nm is reported to characterize the PVC spheres. A PVC PL quenching process is demonstrated to be induced by the increase in the concentration of the GO sheets in the PVC/GO composite mass. The perspectives regarding the use of this composite as a flame-retardant material are also reported.

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Soluble graphene composite with aggregation-induced emission feature: non-covalent functionalization and application in explosive detection

Journal of Materials Chemistry C ◽

10.1039/c7tc01194f ◽

2017 ◽

Vol 5 (25) ◽

pp. 6216-6223 ◽

Cited By ~ 15

Author(s):

Peiying Li ◽

Zhan Qu ◽

Xin Chen ◽

Xiankuan Huo ◽

Xiucheng Zheng ◽

...

Keyword(s):

Graphene Oxide ◽

Chemical Reduction ◽

Emission Feature ◽

Explosive Detection ◽

Covalent Functionalization ◽

Aggregation Induced Emission ◽

Wet Chemistry ◽

Graphene Composite ◽

First Time

Herein, a soluble graphene-based material exhibiting the aggregation-induced emission (AIE) feature was prepared for the first time via wet chemistry by the chemical reduction of graphene oxide (GO).

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Layer by layer assembled functionalized graphene oxide-based polymer brushes for superlubricity on steel-steel tribocontact

Soft Matter ◽

10.1039/d1sm00690h ◽

2021 ◽

Author(s):

Suprakash Samanta ◽

Rashmi Ranjan Sahoo

Keyword(s):

Graphene Oxide ◽

Nucleophilic Addition ◽

Polymer Brushes ◽

Addition Reaction ◽

Layer By Layer ◽

Functionalized Graphene ◽

Covalent Functionalization ◽

Functionalized Graphene Oxide ◽

Nucleophilic Addition Reaction ◽

Branched Polyethylenimine

Present study demonstrates a simple and multistep approach for the preparation of covalent functionalization of chemically prepared graphene oxide (GO) by branched polyethylenimine (PEI) through nucleophilic addition reaction to prepare...

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Temperature-Dependent Photoluminescence of ZnO Thin Films Grown on Off-Axis SiC Substrates by APMOCVD

Materials ◽

10.3390/ma14041035 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1035

Author(s):

Ivan Shtepliuk ◽

Volodymyr Khranovskyy ◽

Arsenii Ievtushenko ◽

Rositsa Yakimova

Keyword(s):

Optical Properties ◽

Structural Quality ◽

Organic Chemical ◽

Zno Films ◽

Vicinal Surfaces ◽

Temperature Dependent ◽

Step Flow ◽

Step Flow Growth ◽

First Time ◽

Temperature Dependent Photoluminescence

The growth of high-quality ZnO layers with optical properties congruent to those of bulk ZnO is still a great challenge. Here, for the first time, we systematically study the morphology and optical properties of ZnO layers grown on SiC substrates with off-cut angles ranging from 0° to 8° by using the atmospheric pressure meta–organic chemical vapor deposition (APMOCVD) technique. Morphology analysis revealed that the formation of the ZnO films on vicinal surfaces with small off-axis angles (1.4°–3.5°) follows the mixed growth mode: from one side, ZnO nucleation still occurs on wide (0001) terraces, but from another side, step-flow growth becomes more apparent with the off-cut angle increasing. We show for the first time that the off-cut angle of 8° provides conditions for step-flow growth of ZnO, resulting in highly improved growth morphology, respectively structural quality. Temperature-dependent photoluminescence (PL) measurements showed a strong dependence of the excitonic emission on the off-cut angle. The dependences of peak parameters for bound exciton and free exciton emissions on temperature were analyzed. The present results provide a correlation between the structural and optical properties of ZnO on vicinal surfaces and can be utilized for controllable ZnO heteroepitaxy on SiC toward device-quality ZnO epitaxial layers with potential applications in nano-optoelectronics.

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Versatile Graphene Oxide Nanosheets via Covalent Functionalization and Their Applications

Materials Chemistry Frontiers ◽

10.1039/d1qm00066g ◽

2021 ◽

Author(s):

Minju Park ◽

Namhee Kim ◽

Jiyoung Lee ◽

Minsu Gu ◽

Byeong-Su Kim

Keyword(s):

Graphene Oxide ◽

Two Dimensional ◽

Graphene Oxide Nanosheets ◽

Covalent Functionalization ◽

Graphene Derivatives

Even though many graphene derivatives that are atomically thin two-dimensional structures, such as graphene oxide (GO), have triggered enormous interest in the scientific and industrial communities owing to their easy...

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Retraction notice to “Covalent functionalization mediated anchoring of gold nanoparticles on graphene oxide surface: A unique approach for electrode preparation” [Chem. Phys. Lett. 778 (2021) 138822]

Chemical Physics Letters ◽

10.1016/j.cplett.2021.139002 ◽

2021 ◽

Vol 782 ◽

pp. 139002

Author(s):

Tapan Kumar Behera ◽

Snehalata Pradhan ◽

Priyanka Behera ◽

Pramoda Kumar Satapathy ◽

Priyabrat Mohapatra

Keyword(s):

Gold Nanoparticles ◽

Graphene Oxide ◽

Chem Phys ◽

Oxide Surface ◽

Covalent Functionalization ◽

Unique Approach ◽

Retraction Notice

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Surface activated carbon nitride nanosheets with optimized electro-optical properties for highly efficient photocatalytic hydrogen production

Journal of Materials Chemistry A ◽

10.1039/c5ta10194h ◽

2016 ◽

Vol 4 (7) ◽

pp. 2445-2452 ◽

Cited By ~ 86

Author(s):

Mohammad Ziaur Rahman ◽

Jingrun Ran ◽

Youhong Tang ◽

Mietek Jaroniec ◽

Shi Zhang Qiao

Keyword(s):

Optical Properties ◽

Activated Carbon ◽

Hydrogen Production ◽

Carbon Nitride ◽

Surface Activation ◽

Step Method ◽

Highly Efficient ◽

Thin Carbon ◽

Carbon Nitride Nanosheets ◽

First Time

We introduce a three-step method (co-polymerization, surface activation and exfoliation) for the first time to synthesize sub-nanometer-thin carbon nitride nanosheets as highly efficient hydrogen evolution photocatalysts.

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ARCHITECTURE OF FLOWER-LIKE rGO/CNTs-LOADED CuxO NANOPARTICLES AND ITS PHOTOCATALYTIC PROPERTIES

NANO ◽

10.1142/s1793292013500525 ◽

2013 ◽

Vol 08 (05) ◽

pp. 1350052 ◽

Cited By ~ 6

Author(s):

BIN ZENG ◽

XIAOHUA CHEN ◽

XUTAO NING ◽

CHUANSHENG CHEN ◽

HUI LONG

Keyword(s):

Electron Microscopy ◽

Photocatalytic Performance ◽

Degradation Process ◽

Photocatalytic Properties ◽

High Concentration ◽

Graphene Oxides ◽

Transmission Electron ◽

Time Scanning ◽

Reduced Graphene ◽

First Time

Novel flower-like composite architecture was successfully synthesized by spray drying and post-calcinating method for the first time. Scanning electron microscopy and transmission electron microscopy observations confirmed that reduced graphene oxides/carbon nanotubes hybrid (rGO/CNTs) formed a flower-like micrometer structure and Cu2O , CuO ( Cu x O , x = 1 or 2) nanoparticles were decorated inside them. The photocatalytic properties were further investigated by evaluating the photodegradation of a pollutant methyl orange (MO). The experimental results indicated that this novel architecture enhanced photocatalytic performance with 96.2% decomposition of MO after 25 min in the presence of H 2 O 2 under visible light irradiation, which was much higher than that of Cu x O powders (33.2%). This could be attributed to the more efficient adsorption of MO molecules on flower-like rGO/CNTs and provide a high concentration of MO near to the Cu x O nanoparticles, thus promoting the photocatalytic degradation process.

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