Next Issue
Previous Issue

Table of Contents

C, Volume 5, Issue 1 (March 2019)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-13
Export citation of selected articles as:
Open AccessArticle Novel Biobased Polyol Using Corn Oil for Highly Flame-Retardant Polyurethane Foams
Received: 31 January 2019 / Revised: 5 March 2019 / Accepted: 11 March 2019 / Published: 14 March 2019
Viewed by 221 | PDF Full-text (4206 KB) | HTML Full-text | XML Full-text
Abstract
A novel bio-based polyol was synthesized using corn oil and 2-mercaptoethanol via thiol-ene reaction as an alternative to petroleum-based polyol for the synthesis of polyurethane foams. The polyol was analyzed using wet chemical techniques to obtain hydroxyl number and viscosity. Infrared spectroscopy and [...] Read more.
A novel bio-based polyol was synthesized using corn oil and 2-mercaptoethanol via thiol-ene reaction as an alternative to petroleum-based polyol for the synthesis of polyurethane foams. The polyol was analyzed using wet chemical techniques to obtain hydroxyl number and viscosity. Infrared spectroscopy and gel permeation chromatography were used to confirm the structural properties of the foams. Flame-retardant polyurethane foams were prepared by the addition of different concentrations of dimethyl methyl phosphonate (DMMP) in final foam composition. The effect of DMMP on the thermo-mechanical properties of the polyurethane foams was analyzed. The TGA analysis showed improved stability of the final char with addition of DMMP in the foams. All the foams maintained a well-defined cellular structure and over 95% of closed cell content. The horizontal burning test showed reduced burning time and weight loss from 115 s and 38 wt.% for the neat foams, to 3.5 s and 5.5 wt.% for DMMP-containing foams (1.94 wt.% P). The combustion test using cone calorimeter showed a considerable reduction in heat release rate and total heat release. Thus, our study shows that corn-oil based polyol can be used to produce renewable polyol for industrially producible rigid polyurethane foams. The addition of a small amount of DMMP could result in a significant reduction in the flame-retardant properties of the polyurethane foams. Full article
(This article belongs to the Special Issue Advanced Coal, Biomass and Waste Conversion Technologies)
Figures

Graphical abstract

Open AccessArticle Fluorescent Carbon Dots Ink for Gravure Printing
Received: 8 February 2019 / Revised: 5 March 2019 / Accepted: 8 March 2019 / Published: 14 March 2019
Viewed by 227 | PDF Full-text (1994 KB) | HTML Full-text | XML Full-text
Abstract
In the present article, we describe the use of highly fluorescent carbon dots (CDs) for the preparation of an effective water-based carbon dot ink (CD-ink) for gravure printing. Carbon dots were prepared hydrothermally from citrate and triethylenetetramine, and mixed properly with certain resins [...] Read more.
In the present article, we describe the use of highly fluorescent carbon dots (CDs) for the preparation of an effective water-based carbon dot ink (CD-ink) for gravure printing. Carbon dots were prepared hydrothermally from citrate and triethylenetetramine, and mixed properly with certain resins that are used in gravure inks. The as-produced CD gravure ink was used successfully for printing high quality fluorescent images. Full article
(This article belongs to the Special Issue Recent Advances in Carbon Dots)
Figures

Graphical abstract

Open AccessArticle Plasma Oxidation Printing into DLC and Graphite for Surface Functionalization
Received: 18 December 2018 / Revised: 22 February 2019 / Accepted: 26 February 2019 / Published: 11 March 2019
Viewed by 216 | PDF Full-text (5989 KB) | HTML Full-text | XML Full-text
Abstract
A diamond-like carbon (DLC) film, coated on a AISI420-J2 stainless steel substrate and vertically aligned graphite (VAG), was structured by high-density plasma oxidation to work as a DLC-punch for micro-stamping and DLC-nozzle array for micro-dispensing, in addition to acting as a copper-plated thermal [...] Read more.
A diamond-like carbon (DLC) film, coated on a AISI420-J2 stainless steel substrate and vertically aligned graphite (VAG), was structured by high-density plasma oxidation to work as a DLC-punch for micro-stamping and DLC-nozzle array for micro-dispensing, in addition to acting as a copper-plated thermal spreader, respectively. Thick DLC films were micro-patterned by maskless lithography and directly plasma-etched to remove the unmasked regions. Thick VAG (Ca plates were micro-patterned by screen-printing and selectively etched to activate the surface. Raman spectroscopy as well as electric resistivity measurement proved that there was no degradation of VAG by this surface activation. Wet plating was utilized to prove that copper wettability was improved by this surface treatment. Full article
(This article belongs to the Special Issue Plasma Processing for Carbon-based Materials)
Figures

Figure 1

Open AccessArticle Rice Husk-Derived High Surface Area Nanoporous Carbon Materials with Excellent Iodine and Methylene Blue Adsorption Properties
Received: 26 January 2019 / Revised: 16 February 2019 / Accepted: 19 February 2019 / Published: 22 February 2019
Viewed by 361 | PDF Full-text (2519 KB) | HTML Full-text | XML Full-text
Abstract
Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide [...] Read more.
Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide solution. The silica-free rice husk char was mixed with chemical activating agents sodium hydroxide (NaOH), zinc chloride (ZnCl2), and potassium hydroxide (KOH) separately at a mixing ratio of 1:1 (wt%) and carbonized at 900 °C under a constant flow of nitrogen. The prepared carbon materials were characterized by scanning electron microscopy (SEM), Fourier transformed-infrared spectroscopy (FT-IR), powder X-ray diffraction (pXRD), and Raman scattering. Due to the presence of bimodal micro- and mesopore structures, KOH activated samples showed high specific surface area ca. 2342 m2/g and large pore volume ca. 2.94 cm3/g. Oxygenated surface functional groups (hydroxyl, carbonyl, and carboxyl) were commonly observed in all of the samples and were essentially non-crystalline porous particle size of different sizes (<200 μm). Adsorption study revealed that KOH activated samples could be excellent material for the iodine and methylene blue adsorption from aqueous phase. Iodine and methylene blue number were ca. 1726 mg/g and 608 mg/g, respectively. The observed excellent iodine and methylene blue adsorption properties can be attributed to the well-developed micro- and mesopore structure in the carbon material. This study demonstrates that the agricultural waste, rice husk, and derived nanoporous carbon materials would be excellent adsorbent materials in water purifications. Full article
Figures

Graphical abstract

Open AccessCommunication Novel Tubular Carbon Membranes Prepared from Natural Rattans
Received: 7 December 2018 / Revised: 22 January 2019 / Accepted: 29 January 2019 / Published: 1 February 2019
Viewed by 273 | PDF Full-text (1579 KB) | HTML Full-text | XML Full-text
Abstract
The novel tubular carbon membranes produced from natural materials are, for the first time, reported. The novelty of this idea is to use natural rattans as precursors for making carbon membranes to address the challenges of cellulose polymers. The rattan precursors were carbonized [...] Read more.
The novel tubular carbon membranes produced from natural materials are, for the first time, reported. The novelty of this idea is to use natural rattans as precursors for making carbon membranes to address the challenges of cellulose polymers. The rattan precursors were carbonized to present evenly distributed channels inside the tubular carbon membranes. Each channel has an inner diameter of 2 × 10−4 m with a dense-selective inner layer and a porous outer layer. Future work on selection of suitable rattans, proper pre-treatment, carbon structure tailoring can be conducted to open a new research field of carbon membranes/materials. Full article
Figures

Graphical abstract

Open AccessArticle Effects of Ion Bombardment Energy Flux on Chemical Compositions and Structures of Hydrogenated Amorphous Carbon Films Grown by a Radical-Injection Plasma-Enhanced Chemical Vapor Deposition
Received: 23 December 2018 / Revised: 14 January 2019 / Accepted: 18 January 2019 / Published: 24 January 2019
Viewed by 327 | PDF Full-text (1901 KB) | HTML Full-text | XML Full-text
Abstract
Hydrogenated amorphous carbon (a-C:H) films have attracted much attention, because of their excellent physical and chemical properties, such as high mechanical hardness, chemical robustness, a wide variety of optical bandgaps, and so forth. Although an ion bombardment energy has been regarded as essential [...] Read more.
Hydrogenated amorphous carbon (a-C:H) films have attracted much attention, because of their excellent physical and chemical properties, such as high mechanical hardness, chemical robustness, a wide variety of optical bandgaps, and so forth. Although an ion bombardment energy has been regarded as essential in the well-know subplantation model, it alone is inadequate especially in complicated reactions of a plasma-enhanced chemical vapor deposition process. In this study, an ion bombardment energy flux (ΓEi) was proposed as a crucial factor to determine chemical compositions and structures of a-C:H films. To obtain the amounts of ΓEi, electron densities, hydrogen (H) excitation temperatures, and negative direct current (DC) self-bias voltage (-VDC) were measured. The deposition rate increased, and sp2-C clusters incorporation was induced by the ΓEi. With increasing ΓEi, photoluminescence (PL) backgrounds in Raman spectra decreased, while spin densities in electron spin resonance (ESR) measurements increased. These results suggested the H content of a-C:H film decreased depending on the amount of ΓEi. The ΓEi is one of the crucial factors to determine the properties of the a-C:H films. Full article
Figures

Graphical abstract

Open AccessArticle Electrochemical Reaction in Hydrogen Peroxide and Structural Change of Platinum Nanoparticle-Supported Carbon Nanowalls Grown Using Plasma-Enhanced Chemical Vapor Deposition
Received: 3 December 2018 / Revised: 4 January 2019 / Accepted: 17 January 2019 / Published: 24 January 2019
Viewed by 386 | PDF Full-text (4163 KB) | HTML Full-text | XML Full-text
Abstract
Hydrogen peroxide (H2O2) reactions on platinum nanoparticle-decorated carbon nanowalls (Pt-CNWs) under potential applications were investigated on a platform of CNWs grown on carbon fiber paper (CFP) using plasma-enhanced chemical vapor deposition. Through repeated cyclic voltammetry (CV), measurements of 1000 [...] Read more.
Hydrogen peroxide (H2O2) reactions on platinum nanoparticle-decorated carbon nanowalls (Pt-CNWs) under potential applications were investigated on a platform of CNWs grown on carbon fiber paper (CFP) using plasma-enhanced chemical vapor deposition. Through repeated cyclic voltammetry (CV), measurements of 1000 cycles using the Pt-CNW electrodes in phosphate-buffered saline (PBS) solution with 240 μM of H2O2, the observed response peak currents of H2O2 reduction decreased with the number of cycles, which is attributed to decomposition of H2O2. After CV measurements for a total of 3000 cycles, the density and height of CNWs were reduced and their surface morphology changed. Energy-dispersive X-ray (EDX) compositional mapping revealed agglomeration of Pt nanoparticles around the top edges of CNWs. The degradation mechanism of Pt-CNWs under potential application with H2O2 is discussed by focusing on the behavior of OH radicals generated by the H2O2 reduction. Full article
(This article belongs to the Special Issue Plasma Processing for Carbon-based Materials)
Figures

Graphical abstract

Open AccessCommunication Convenient Preparation of Graphene Oxide from Expandable Graphite and Its Characterization by Positron Annihilation Lifetime Spectroscopy
Received: 12 December 2018 / Revised: 4 January 2019 / Accepted: 7 January 2019 / Published: 11 January 2019
Cited by 1 | Viewed by 379 | PDF Full-text (1821 KB) | HTML Full-text | XML Full-text
Abstract
Graphene oxide (GO) is conveniently prepared from expandable graphite using a simplified Hummers’ method. The product is thoroughly characterized by usual techniques (UV-vis, Fourier-transform infrared (FTIR) and Raman spectroscopies, zeta potential, electron microscopy, X-ray diffraction, nitrogen adsorption) to confirm the success of synthesis. [...] Read more.
Graphene oxide (GO) is conveniently prepared from expandable graphite using a simplified Hummers’ method. The product is thoroughly characterized by usual techniques (UV-vis, Fourier-transform infrared (FTIR) and Raman spectroscopies, zeta potential, electron microscopy, X-ray diffraction, nitrogen adsorption) to confirm the success of synthesis. Positron annihilation lifetime spectroscopy (PALS) is then used to extract information on the microenvironment in between the layers of graphene oxide. Full article
Figures

Graphical abstract

Open AccessEditorial Acknowledgement to Reviewers of C in 2018
Published: 9 January 2019
Viewed by 311 | PDF Full-text (221 KB) | HTML Full-text | XML Full-text
Abstract
Rigorous peer-review is the corner-stone of high-quality academic publishing [...] Full article
Open AccessArticle Experimental Investigation of the Mechanisms of Salt Precipitation during CO2 Injection in Sandstone
Received: 27 November 2018 / Revised: 28 December 2018 / Accepted: 3 January 2019 / Published: 8 January 2019
Viewed by 304 | PDF Full-text (2889 KB) | HTML Full-text | XML Full-text
Abstract
Deep saline reservoirs have the highest volumetric CO2 storage potential, but drying and salt precipitation during CO2 injection could severely impair CO2 injectivity. The physical mechanisms and impact of salt precipitation, especially in the injection area, is still not fully [...] Read more.
Deep saline reservoirs have the highest volumetric CO2 storage potential, but drying and salt precipitation during CO2 injection could severely impair CO2 injectivity. The physical mechanisms and impact of salt precipitation, especially in the injection area, is still not fully understood. Core-flood experiments were conducted to investigate the mechanisms of external and internal salt precipitation in sandstone rocks. CO2 Low Salinity Alternating Gas (CO2-LSWAG) injection as a potential mitigation technique to reduce injectivity impairment induced by salt precipitation was also studied. We found that poor sweep and high brine salinity could increase salt deposition on the surface of the injection area. The results also indicate that the amount of salt precipitated in the dry-out zone does not change significantly during the drying process, as large portion of the precipitated salt accumulate in the injection vicinity. However, the distribution of salt in the dry-out zone was found to change markedly when more CO2 was injected after salt precipitation. This suggests that CO2 injectivity impairment induced by salt precipitation is probably dynamic rather than a static process. It was also found that CO2-LSWAG could improve CO2 injectivity after salt precipitation. However, below a critical diluent brine salinity, CO2-LSWAG did not improve injectivity. These findings provide vital understanding of core-scale physical mechanisms of the impact of salt precipitation on CO2 injectivity in saline reservoirs. The insight gained could be implemented in simulation models to improve the quantification of injectivity losses during CO2 injection into saline sandstone reservoirs. Full article
Figures

Figure 1

Open AccessReview An Overview of the Recent Progress in the Synthesis and Applications of Carbon Nanotubes
Received: 13 October 2018 / Revised: 24 December 2018 / Accepted: 27 December 2018 / Published: 3 January 2019
Viewed by 669 | PDF Full-text (8726 KB) | HTML Full-text | XML Full-text
Abstract
Carbon nanotubes (CNTs) are known as nano-architectured allotropes of carbon, having graphene sheets that are wrapped forming a cylindrical shape. Rolling of graphene sheets in different ways makes CNTs either metals or narrow-band semiconductors. Over the years, researchers have devoted much attention to [...] Read more.
Carbon nanotubes (CNTs) are known as nano-architectured allotropes of carbon, having graphene sheets that are wrapped forming a cylindrical shape. Rolling of graphene sheets in different ways makes CNTs either metals or narrow-band semiconductors. Over the years, researchers have devoted much attention to understanding the intriguing properties CNTs. They exhibit some unusual properties like a high degree of stiffness, a large length-to-diameter ratio, and exceptional resilience, and for this reason, they are used in a variety of applications. These properties can be manipulated by controlling the diameter, chirality, wall nature, and length of CNTs which are in turn, synthesis procedure-dependent. In this review article, various synthesis methods for the production of CNTs are thoroughly elaborated. Several characterization methods are also described in the paper. The applications of CNTs in various technologically important fields are discussed in detail. Finally, future prospects of CNTs are outlined in view of their commercial applications. Full article
Figures

Graphical abstract

Open AccessArticle Nanostructure Quantification of Carbon Blacks
Received: 20 November 2018 / Revised: 8 December 2018 / Accepted: 21 December 2018 / Published: 31 December 2018
Cited by 1 | Viewed by 624 | PDF Full-text (7067 KB) | HTML Full-text | XML Full-text
Abstract
Carbon blacks are an extensively used manufactured product. There exist different grades by which the carbon black is classified, based on its purpose and end use. Different properties inherent to the various carbon black types are a result of their production processes. Based [...] Read more.
Carbon blacks are an extensively used manufactured product. There exist different grades by which the carbon black is classified, based on its purpose and end use. Different properties inherent to the various carbon black types are a result of their production processes. Based on the combustion condition and fuel used, each process results in a carbon black separate from those obtained from other processes. These carbons differ in their aggregate morphology, particle size, and particle nanostructure. Nanostructure is key in determining the material’s behavior in bulk form. A variety of carbon blacks have been analyzed and quantified for their lattice parameters and structure at the nanometer scale, using transmission electron microscopy and custom-developed fringe analysis algorithms, to illustrate differences in nanostructure and their potential relation to observed material properties. Full article
Figures

Graphical abstract

Open AccessArticle Carbon-Based Magnetic Nanocarrier for Controlled Drug Release: A Green Synthesis Approach
Received: 15 November 2018 / Revised: 15 December 2018 / Accepted: 22 December 2018 / Published: 28 December 2018
Viewed by 434 | PDF Full-text (4391 KB) | HTML Full-text | XML Full-text
Abstract
In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, [...] Read more.
In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release. Full article
(This article belongs to the Special Issue Biomedical Applications of Carbon Materials)
Figures

Graphical abstract

C EISSN 2311-5629 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top