• Title/Summary/Keyword: functionalization

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Emerging Frontiers of Graphene in Biomedicine

  • Byun, Jonghoe
    • Journal of Microbiology and Biotechnology
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    • v.25 no.2
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    • pp.145-151
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    • 2015
  • Graphene is a next-generation biomaterial with increasing biomedical applicability. As a new class of one-atom-thick nanosheets, it is a true two-dimensional honeycomb network nanomaterial that attracts interest in various scientific fields and is rapidly becoming the most widely studied carbon-based material. Since its discovery in 2004, its unique optical, mechanical, electronic, thermal, and magnetic properties are the basis of exploration of the potential applicability of graphene. Graphene materials, such as graphene oxide and its reduced form, are studied extensively in the biotechnology arena owing to their multivalent functionalization and efficient surface loading with various biomolecules. This review provides a brief summary of the recent progress in graphene and graphene oxide biological research together with current findings to spark novel applications in biomedicine. Graphene-based applications are progressively developing; hence, the opportunities and challenges of this rapidly growing field are discussed together with the versatility of these multifaceted materials.

Dispersion of Single-Walled Carbon Nanotubes for Display Applications

  • Manivannan, S.;Ryu, Je-Hwang;Jeong, Il-Ok;Lee, Chang-Seok;Kim, Ki-Seo;Jang, Jin;Park, Kyu-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1625-1628
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    • 2007
  • Dispersion of arc-discharged single-walled carbon nanotubes (SWNTs) has been accomplished by a water soluble polymer wrapping functionalization at room temperature. The treated SWNTs were redispersed in both aqueous and many organic solvents and the solutions were found to be stable.

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Carbon nanotubes-properties and applications: a review

  • Ibrahim, Khalid Saeed
    • Carbon letters
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    • v.14 no.3
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    • pp.131-144
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    • 2013
  • The carbon nanotube (CNT) represents one of the most unique inventions in the field of nanotechnology. CNTs have been studied closely over the last two decades by many researchers around the world due to their great potential in different fields. CNTs are rolled graphene with $SP^2$ hybridization. The important aspects of CNTs are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful as fillers in different materials such as polymers, metallic surfaces and ceramics. CNTs also have potential applications in the field of nanotechnology, nanomedicine, transistors, actuators, sensors, membranes, and capacitors. There are various techniques which can be used for the synthesis of CNTs. These include the arc-discharge method, chemical vaporize deposition (CVD), the laser ablation method, and the sol gel method. CNTs can be single-walled, double-walled and multi-walled. CNTs have unique mechanical, electrical and optical properties, all of which have been extensively studied. The present review is focused on the synthesis, functionalization, properties and applications of CNTs. The toxic effect of CNTs is also presented in a summarized form.

Bio-functionalization of the Single Layer Graphene for Detecting the Cancer Cell

  • Oh, Hyung Sik;Park, Wanjun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.429.1-429.1
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    • 2014
  • We present a method of surface functionalization of a single layer graphene for linking and detecting MDA-MB-231 human breast cancer cell. The methodology is done by utilizing 1-pyrenebutanoic acid and succinimidyl ester for immobiling CD44 antibodies. This work shows that the single layer graphene is an efficient fixing substance to capture the MDA-MB-231 human breast cancer cell, selectively. The immobilization method of the cancer cell on the graphene layer will be an effective cell counting system. Moreover usage of the linking with non-covalent bonding is expected to develope a sensor scheme of electrical cell-detecting diagnosis system.

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Non-Functionalized Water Soluble Carbon Nanotubes

  • Wenping, Wang;Choe, Jeong-Il;Im, Yeon-Min;Kim, Yu-Na;Kim, Chang-Jun;Gang, Sang-Su;Nam, Tae-Hyeon;Gang, Dong-U
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.43.2-43.2
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    • 2010
  • Most of previous methods for the dispersions of carbon nanotube were achieved by various chemical functionalizations. In this study, however, we generated highly water dispersed carbon nanofibers by altering intrinsic materials property only, such as crystallinity of outer layers of carbons, without chemical treatment. Although most of chemical functionalization requires acidic treatment and may degrade their chemical functions by interacting with other molecules, suggested strategy demonstrated a simple but chemically non-degradable carbon nanotube for the application of various medical applications, such as drug delivery system and implant coatings.Furthermore, protein adsorption was increased by the reducing surface crystalinity since outer activated surface induced more adsorption of oxygen and eventually greater protein adsorption than pristine carbon nanofibers.

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Band Structure Engineering of Monolayer MoS2 by Surface Ligand Functionalization

  • Lee, Sang Yoon;Ramzan, Sufyan
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.367-370
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    • 2015
  • Monolayer transition metal dicalcogenide (TMDC) materials are currently attracting extensive attention due to their distinctive electronic, transport, and optical properties. For example, monolayer $MoS_2$ exhibits a direct band gap in the visible frequency range, which makes it an attractive candidate for the photocatalytic water splitting. For the photoelectrochemical water splitting, the appropriate band edge positions that overlap with the water redox potential are necessary. Similarly, appropriate band level alignments will be crucial for the light emitting diode and photovoltaic applications utlizing heterojunctions between two TMDC materials. Carrying out first-principles calculations, we here investigate how the band edges of $MoS_2$ can be adjusted by surface ligand functionalization. This study will provide useful information for the realization of ligand-based band engineering of monolayer $MoS_2$ for various electronic, energy, and bio device applications.

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Synthesis, End-Functionalization and Characterization of Hyperbranched Polysiloxysilanes from $AB_3$ Type Monomer

  • Ishida, Yoshihito;Yokomachi, Kazutoshi;Seino, Makoto;Hayakawa, Teruaki;Kakimoto, Masa-aki
    • Macromolecular Research
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    • v.15 no.2
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    • pp.147-153
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    • 2007
  • Hyperbranched polysiloxysilanes (HBPSs), with a variety of terminal functional groups (vinyl, epoxy, carboxyl and hydroxyl), were synthesized by the self-polymerization of an $AB_3$ type monomer of tris(dimethylvinylsiloxy) silane, with subsequent end-functionalizations, such as epoxidation and radical addition reaction, respectively. The ratio of the $\alpha-and$ $\beta-addition$ linkages in the HBPS polymerized by hydrosilylation of the $AB_3$ monomer was found to be approximately 1 to 3. The thermal stability and solubility were affected by the terminal functional groups.

Noncovalent Modification of Carbon Nanofibers Using 2-Naphthalenethiol for Catalyst Supports in PEM Fuel Cells

  • Oh, Hyung-Suk;Kim, Han-Sung
    • Journal of Electrochemical Science and Technology
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    • v.1 no.2
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    • pp.92-96
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    • 2010
  • A new synthesis method for the preparation of Pt electrocatalysts on carbon nanofibers (CNFs) is reported. In this method, Pt electrocatalysts are loaded onto 2-naphthalenethiol (NT) functionalized CNFs. The noncovalent functionalization of CNFs by NT is the effective way for better distribution of Pt particles and higher electrocatalytic activity in polymer electrolyte membrane fuel cells. It was found that the presence of NT acts as a poison to catalysts. Therefore, it is necessary to remove NT through the heat treatment at $400^{\circ}C$.

Study on the Functionalization of Waste EPDM and PP Blend

  • Chung, Kyungho;Kim, Jinhee
    • Elastomers and Composites
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    • v.50 no.4
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    • pp.245-250
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    • 2015
  • Recycling of ethylene-propylene-diene terpolymer (EPDM) scrap was tried by blending with polypropylene (PP). EPDM scrap powder was prepared by shear pulverization process at high temperature, which may lead to selective chain scission induced by difference in the critical elastic coefficient. On the other hand, EPDM scrap powder was prepared by adding a selected reclaiming agent during shear pulverization process at high temperature. Terpene as a bonding agent was then introduced to improve adhesion property. PP, used as a matrix for manufacturing thermoplastic elastomer, was modified by the incorporation of dicumyl peroxide and maleic anhydride. The functionalized EPDM and modified PP were blended and cured dynamically at $190^{\circ}C$. The blend materials prepared in this study showed the comparable results to those of conventional TPE in terms of tensile and flow properties. Also, the odor component of recycled EPDM was analyzed using GC-MS.

Synthesis, Characterization, and the Influence of Functionalized Multi-Walled Carbon Nanotubes with Creatinine and 2-Aminobenzophenone on the Gastric Cancer Cells

  • Tahermansouri, Hasan;Aryanfar, Yaser;Biazar, Esmaeil
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.149-153
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    • 2013
  • The chemical functionalization of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) by creatinine (MWCNT-Amide) and latter modification with 2-aminobenzophenone for producing 1-methyl-9-phenyl-1H-imidazo[4,5-b]quinolin-2-amine (MWCNT-quino) have been investigated. All products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, elemental analysis, thermogravimetric analysis, derivative thermogravimetric and cellular investigations. The interesting point is that MWCNT-quino can be homogeneously dispersed in dimethylformamide and to some extent in ethyl alcohol without sonication. Also, MTT assay was used to examine the behavior of cell proliferation after 48 h of cell culture experiments. Cellular results showed high toxicity of MWCNT-quino on the cancer cells. These functionalizations have been chosen due to active sites of carbonyl and methylene groups in MWCNT-Amide and the creating quinoline derivative on the MWCNTs for future application.