간행물
Carbon Letters KCI 등재 Carbon letters
- 발행기관 한국탄소학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1976-4251 (Print)2233-4998 (Online)
- 수록기간 2000 ~ 2024
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
Vol.34 No.2 (2024년 4월) 27건
1.
2024.04
구독 인증기관 무료, 개인회원 유료
Carbon dots (CDs) are a novel type of fluorescent nanoparticles with a particle size smaller than 10 nm. They possess several advantageous properties, including excellent biocompatibility, light stability, water solubility, and low toxicity. CDs have been widely researched in recent years. As a treasure of ancient Chinese science, traditional Chinese medicine (TCM) is rich in various active ingredients and has a variety of pharmacodynamic effects, which have been used for thousands of years. TCM-CDs prepared with TCM as carbon source can create some special functions and then may play a greater medicinal value. The purpose of this review was to engage in an in-depth conversation about the use of TCM-CDs in medical therapy and bioimaging. Firstly, this study provides a comprehensive exploration of different synthesis methods for TCM-CDs, comparing their respective advantages and disadvantages. Subsequently, the intrinsic pharmacological activity of TCMCDs, encompassing antibacterial, hypoglycemic, hemostatic, anticancer, and anti-inflammatory effects, is mainly discussed, alongside their underlying mechanisms of action. Additionally, investigations into in vitro imaging of diverse cell types and the distribution and uptake of TCM-CDs under in vivo imaging guidance are presented. Finally, the significance of TCM-CD research, key challenges and issues within this field, and future directions for development are summarized and outlined.
5,500원
2.
2024.04
구독 인증기관 무료, 개인회원 유료
The coatings based on carbon nanotubes (CNTs) are increasingly developed for their applications, among others, in medicine, in particular for implants in implantology, cardiology, and neurology. The present review paper aims at a detailed demonstration of different preparation methods for such coatings, their performance, and relationships between deposition parameters and microstructure and material, mechanical, physical, chemical, and biological properties. The thermal and electrostatic spraying, electrophoretic and electrocathodic deposition, and laser methods are presented. Characterization of microstructure of coatings, topography, morphology, adhesion of CNTs to a substrate, mechanical behavior, corrosion resistance, wettability, cytotoxicity, bioactivity, and antibacterial protection are reviewed for different deposition methods and parameters. The state-of-the-art in the field of carbon nanotubes shows a considerable number of research performed on CNTs coatings. The different forms of CNTs, deposition methods, parameters, and substrates were applied as process variables. The microstructures and surface homogeneity, chemical and phase compositions, mechanical properties at the micro- and nanoscale such as coating Young`s modulus and hardness, interface adhesion strength and delaminating force, open corrosion potential and corrosion current density, contact angle in wettability assessment, and bioactivity, cytotoxicity, and antibacterial efficiency among biological properties were determined. The summary of so far achievements, strengths and weaknesses, and important future research necessary for clarification of some weak points, development of non-toxic, mechanically and chemically resistant, bioactive, and antibacterial multicomponent coatings based on functionalized CNTs are proposed.
8,600원
3.
2024.04
구독 인증기관 무료, 개인회원 유료
Composites of carbon quantum dots (CQDs) are important materials to utilize the optical properties of CQDs in diverse applications including photoluminescence-based sensing and LED phosphors. Combining pre-prepared CQDs with a polymeric matrix usually causes changes in the optical properties of CQDs due to unavoidable aggregation. Recently, the preparation of composites based on in-situ formed CQDs has been debated to overcome the aggregation limits of the conventional mixing methods. Herein, we have demonstrated the synthesis of homogeneous CQDs composites by simple thermal annealing blends of aluminum hydroxide (AlOH), citric acid (CA), and urea (URA). Transmission electron microscopy (TEM), X-ray diffraction, and Raman spectroscopy studies revealed the formation of individual CQDs with a diameter of about 2–9 nm dispersed homogeneously over the AlOH matrix. The composites have a broad excitation band centered at about 360 nm and exhibit excitation-dependent photoluminescence which was similar to that of hydrothermally synthesized CQDs from CA and URA. The photoluminescent intensity of the composite was stable to UV irradiation and responded selectively to Cu(II) ion demonstrating its potential application in Cu(II) sensing.
4,000원
4.
2024.04
구독 인증기관 무료, 개인회원 유료
The effects of different plasma agent species ( CF4, N2) over the conductivity of CFX cathode material were identified. Both plasma treatments have surface etching effect, while the CF4 plasma treatment has C–F bond modification effect and the N2 plasma treatment has defluorination effect. The changes of surface chemical species and porosity along the plasma agent were elucidated. Moreover, the electrochemical properties of plasma-treated CFX confirmed the effects of plasma treatments. The charge-transfer resistance of plasma-treated CFX was maximum 60.3% reduced than the pristine CFX. The effects of surface chemical modification coupled with etching along the plasma gas agents were compared and identified with their reaction mechanisms.
4,000원
5.
2024.04
구독 인증기관 무료, 개인회원 유료
In the present work, multi-walled carbon nanotubes (MWCNT) were anchored with the assistance of vinyl ester resin (VE) on the carbon fiber surfaces of conventional carbon fabrics (CCF) and semi-spread carbon fabrics (SSCF) having different areal density, ply thickness, and crimp number, respectively. Here, MWCNT anchoring means that MWCNT were physically attached on the individual carbon fiber surfaces of each fabric by coating with dilute VE and then by thermally curing it. The MWCNT anchoring effect on the interlaminar shear strength (ILSS) of CCF/VE and SSCF/VE composites was investigated. MWCNT were also simply applied (without physical attachment) to the carbon fiber surfaces of CCF and SSCF for comparison, respectively. It was found that SSCF/VE composites exhibited the ILSS higher than CCF/VE composites, regardless of simple-applying or anchoring of MWCNT, increasing the ILSS with the MWCNT concentration. It was noted that MWCNT anchoring was effective to improve not only the interlaminar adhesion but also the interfacial bonding between the carbon fiber and the matrix due to the formation of MWCNT bridges between the individual carbon fibers of SSCF, indicating that the MWCNT anchoring effect was more pronounced with SSCF than with CCF. The result of the interlaminar property was well supported by the fiber and composite fracture topography.
4,000원
6.
2024.04
구독 인증기관 무료, 개인회원 유료
Efficient Li-ion transport in anode materials is paramount for electric vehicles (EVs) and energy storage systems. The rapid charging demands of EVs can lead capacity decay at high charging rate. To overcome this challenge, we focus on graphite geometric characteristics that effect to interparticle space. We interpret the correlation between the utilization of the electrode and the interparticle space where solvated Li-ion transports in liquid electrolyte. To introduce variability into this space, two main coke precursors, coal cokes and petroleum cokes, were prepared and further categorized as normal cokes and needle cokes. Manufactured graphite samples were observed with distinct geometric characteristics. In this study, investigates the impact of these geometric variations on electrochemical performance, emphasizing rate capability and cycle stability during fast charging. By analyzing the transport properties of electrochemical species within these graphite samples, we reveal the critical role of morphology in mitigating concentration polarization and side reaction, such as Li-plating. These findings offer promising contribution for the development of advanced anode materials, in fast-charging condition in Li-ion.
4,000원
7.
2024.04
구독 인증기관 무료, 개인회원 유료
A combination of a series of epoxy coatings filled with octadecylamine (ODA)-modified graphene oxide (mGO) or commercial exfoliated graphite nanoplatelets (xGnP) was developed to boost the anticorrosion performances of mild steel substrates in acidic and NaCl aqueous solutions. The xGnP and mGO were applied successfully as fillers for the preparation of layer by layer (LBL) xGnP or mGO/epoxy coatings, respectively, which were coated on the clean steel surfaces to form LBLassembled layers. The LBL-assembled xGnP or mGO/epoxy coating-coated steel substrates exhibit excellent anticorrosion performances. The corrosion potentials (Ecorr) of xGnP-1/xGnP-2/3 and mGO-1/mGO-2/3 display at − 193 and − 150 mV, respectively, while Ecorr of the bare steel shows at − 871 mV of immersion in the 3.5 wt% NaCl solution. The most positive Ecorr values are obtained for xGnP-1/2/3 (− 117 mV) and mGO-1/2/3 (− 66 mV), showing the best anticorrosion performances compared to the bare steel (− 404 mV) in 17 wt% HCl solution.
4,000원
8.
2024.04
구독 인증기관 무료, 개인회원 유료
This study aimed to fabricate composites with high thermal conductivity using diglycidyl ether of bisphenol-A (DGEBA), incorporating carbon fiber cloth (CFC) and graphene as reinforcing agents. Notably, the dispersion of graphene within the DGEBA matrix was enhanced through surface modification via a silane coupling agent. The effects of CFC and graphene addition on the impact strength, thermal conductivity, and morphology of the composites were examined. The experimental results showed that the incorporation of 6 wt% CFC resulted in a substantial (16-fold) increase in impact strength. Furthermore, the introduction of 6 wt% CFCs along with 20 wt% graphene led to a remarkable enhancement in thermal conductivity to 5.7 W/(m K), which was approximately 22 and 4 times higher than the intrinsic thermal conductivities of pristine DGEBA and the CFC/DGEBA composite, respectively. The increased impact strength is ascribed to the incorporation of CFC and silane-modified graphene. Additionally, the gradual increase in thermal conductivity can be attributed to the enhanced interaction between the acidic silane-modified graphene and the basic epoxy–amine hardener within the system studied.
4,000원
9.
2024.04
구독 인증기관 무료, 개인회원 유료
We report a simple benchtop method to synthesize diamonds from ethyl alcohol ( C2H6O) at ambient pressure and room temperature via solvothermal reactions in a liquid solution of table salt (NaCl) and their structural characterization using electron diffraction and high-resolution electron microscopy. In addition to the usual cubic phase of diamond, the hexagonal phase of diamond (lonsdaleite) has also been obtained and identified unambiguously. Many of the synthesized diamonds often contain structural defects including twinnings, stacking faults, and dislocations. The formation and growth of diamond under ambient conditions provide further insights into understanding of the natural existence of diamond on Earth as well as in outer space. While only nanometric diamonds have been observed in the present study, we believe this discovery will open up new ways that have long been sought to grow diamonds, including large size diamonds, in organic solutions at ambient conditions.
4,000원
10.
2024.04
구독 인증기관 무료, 개인회원 유료
Mengyao Ling, Ningning Yin, Yifan Chen, Zenan Zhou, Haifeng Chen, Chunping Dai, Jingda Huang, Wenbiao Zhang
Polylactic acid (PLA) is often used in the preparation of environmentally friendly biodegradable polymer plastics, and how to improve the flame retardant performance of polylactic acid has been concerned by experts and scholars. Here, we provide a new idea, using bamboo activated carbon as the main material, and phytic acid, urea and Zn(NO3)2·6(H2O) as modifiers to produce a new type of carbon flame retardant. It has bamboo activated carbon as carbon source; second, it has P, N elements and metal oxides. The two synergistically play a flame retardant role on polylactic acid. The polylactic acid composite showed good thermal stability, from no grade optimization to V-0 in the UL-94 test, and the limiting oxygen index was also increased from 20.1 to 31.2%. The above tests show that bamboo activated carbon loaded with ZnO has a good flame retardant effect on polylactic acid.
4,200원
11.
2024.04
구독 인증기관 무료, 개인회원 유료
Large-area porous carbon is easily produced for supercapacitors from polyvinylidene chloride (PVDC) and polyvinylidene fluoride (PVDF) precursors, composed of carbon backbone and attached heteroatoms. The released heteroatoms during pyrolysis leave the porous carbon. This study explored the activation of both precursors using chemical agents (ZnO, Mg(OH)2, and KOH) to develop carbon with multiple micropores and mesopores. The activation process and relevant precursors were studied to implement synthesized porous carbon as an electrode in supercapacitors. During the activation of PVDC-resin, ZnO served both as templates and activating agents, while Mg(OH)2 served only as a template, and KOH served as an activating agent. For activation of PVDF, ZnO acted as a template and activating agent, whereas Mg(OH)2 and KOH impeded activation owing to side reactions. Therefore, with the above chemical agents, PVDC-resin was converted to carbon with a higher surface area than PVDF. The porous carbon produced using PVDC-resin with KOH had the highest specific capacitance of 137 F g− 1 and rate performance of 79% at 50 mV s− 1 (vs. 5 mV s− 1) owing to the successful creation of micropores and mesopores. This study identifies optimal conditions for synthesizing porous carbon using polymer precursors and chemical agents for supercapacitors.
4,600원
12.
2024.04
구독 인증기관 무료, 개인회원 유료
In this study, Pitch-derived activated carbon (PAC) pellets were by steam activation for automotive carbon canisters. The crystal structure of PAC was analyzed using X-ray diffraction. The textural properties of PAC were studied by Brunauer– Emmett–Teller (BET), Horvath-Kawazoe (HK), and Non-Localized Density Functional Theory (NLDFT) equations with N2/ 77 K isotherm adsorption/ desorption curves. The butane adsorption capacity of the PAC pellets was analyzed according to the ASTM D5228 standard. With increasing steam activation time, the specific surface area and total pore volume of the PAC increased 650–1950 m2/ g and 0.27–1.02 cm3/ g, respectively. The mesopore ratio of PAC increased with increasing activation time and was observed up to 28.4% at 190 min. The butane adsorption capacity of the PAC increased and was observed to range from 10.86 to 51.55%. A close relationship between butane adsorption capacity and pore size (1.47–2.39 nm) was found. Finally, the butane activity of PAC was found to be 51.55% for the steam activated at 950 ℃ for 190 min; this butane activity is 24% better than that of the coconut-derived activated carbon (41.43%) with a similar specific surface area, indicating that pitch is a suitable material for the activated carbon of automotive carbon canisters.
4,200원
13.
2024.04
구독 인증기관 무료, 개인회원 유료
Shangyin Jia, Ying Han, Zhihao Liu, Jin Qiao, Da Bao, Linna Tian, Bin Zhang, Xiaohang Tuo, Jing Guo, Sen Zhang
The challenge of incorporating photothermal conversion function into chitosan (CS) hybrid fibers lies in balancing functionality and mechanical properties. In this study, we successfully prepared a chitosan/graphene oxide/gelatin (CS/GA/GO) hybrid fiber using the wet spinning process, achieving improved mechanical properties and efficient photothermal conversion capabilities. When compared with pure CS fiber with a breaking strength of 1.07 cN/dtex, the breaking strength of the CS/ GA composite fiber increased by 46.73%, while the CS/GA/GO hybrid fiber showed an even greater increase of 85.98%. In addition, the introduction of gelatin (GA) led to secondary scattering of near-infrared light, enhancing the photothermal conversion efficiency. As a result, the CS/GA/GO hybrid fiber exhibited a faster temperature rise rate and higher maximum temperatures (94.3 °C, 103.0 °C, and 111.3 °C) as compared to the CS/GO hybrid fiber. The successful incorporation of GA not only improved the mechanical properties but also enhanced the photothermal performance of the hybrid fiber.
4,200원
14.
2024.04
구독 인증기관 무료, 개인회원 유료
In this study, we utilized a multi-step stabilization method, incorporating dry-oxidation, to produce high-density polyethylene (HDPE)-based activated carbon fibers. This stabilization was achieved through electron-beam irradiation, sulfonation, and dry oxidation. The stabilized fibers were carbonized and activated at 900 ℃. The crystallite characteristics of the activated carbon fibers were observed using X-ray diffraction, and their surface morphologies were analyzed through scanning electron microscopy. The textural properties were analyzed using N2/ 77 K adsorption–desorption isothermal curves. And leveraging the microdomain model, we explored the influence of these stabilization methods on the HDPE-based activated carbon fibers texture properties. The results show that HDPE fibers treated with sulfonation only at 100 ℃ for 60 min were not sufficiently cross-linked and were completely decomposed during the carbonization stage. However, the sulfonated fibers treated with the new dry-oxidation process maintained their shapes and were successfully activated. The specific surface area of the resulting activated carbon fibers was as much as 2000 m2/ g.
4,000원
15.
2024.04
구독 인증기관 무료, 개인회원 유료
Porous carbon nanofiber (CNF) electrodes for supercapacitors were prepared by using polyacrylonitrile (PAN) and cucurbituril (CB), which is a macrocyclic compound comprising glycoluril units containing hollow cores. Mixture of PAN and CB in dimethyl sulfoxide was electrospun, and thermally treated to produce CNF electrodes. Their thermal stability, surface morphology, carbon microstructures, and surface porosity were investigated. Electrochemical properties were measured using three-electrode with synthesized CNFs without further treatment as a working electrode and 1 M Na2SO4 as an electrolyte. CNFs derived from PAN and CB exhibited a high specific capacitance of 183.5 F g− 1 and an energy density of 25.4 Wh kg− 1 at 0.5 A g− 1 with stable cyclic stability during 1000 cycles, which is significantly higher than those for CNFs derived from PAN only. This demonstrated that the introduction of CB successfully improved the energy storage performance of CNF electrodes.
4,000원
16.
2024.04
구독 인증기관 무료, 개인회원 유료
This paper investigates the effect of seashell (SS) powders of 75 μm size, reinforced in multi-walled carbon nanotube (MWCNT)-added nylon 66 polymer composite, by studying its mechanical and thermal properties for suitable application in the automotive industry. Seashells were collected from the seashores and the mechanical ball milling method is employed to ground the SSs into powders using a sieve machine, and the desired particulate size of 75 μm is obtained. These particulate SSs are reinforced in the matrix of nylon 66 in different proportions, viz., 3, 6, 9, 12, and 15% by weight along with 1 wt.% of MWCNTs. Twin-screw extruder and injection molding are employed to prepare the testing specimens. Mechanical and thermal tests were carried out as per ASTM standards. From the mechanical and thermal analyses, it is observed that tensile strength and coefficient of linear thermal expansion decrease with an increase in SS content, whereas flexural strength, shore hardness, impact strength, Vicat softening point, and heat deflection temperature rise with higher wt.% of SSs. This is owing to the thermoplastic’s decreased flexibility, which increases its resilience to deflection and load and its high thermal stability. The added MWCNTs improved the bonding strength and mechanical properties due to their higher surface areato- volume ratio.
4,300원
17.
2024.04
구독 인증기관 무료, 개인회원 유료
Nithya Ramasamy, Anbudayanidhi Sivalingam, Shanmuga Sundar Saravanabhavan, Kavitha Nagarasampatti Palani, Balasubramanian Natesan
The development of biocomposites using renewable resources is a cost-effective and long-term solution to environmental and resource issues. Hydrogels [Poly Sodium Acrylate (PSA)] were created by variable percentages of crosslinker concentration, and banana–cellulose microfibril (CMF) was used as a filler in this study for better reinforcement. When the concentration of crosslinker is increased, the number of covalent crosslinks increases, limiting the movement of water molecules and lowering the diffusion coefficient, equilibrium water content, the initial rate of swelling, and the theoretical equilibrium swelling ratio. The swelling behaviour of reinforced PSA with high concentrations of CMF was unexpected; the hydrophilic OH groups of CMF increase the diffusion of water molecules from the swelling medium to inside the PSA, allowing for better mechanical behaviour of gels without sacrificing the swelling response. The swelling behaviour and swelling exponent of a hydrogel were determined at various temperatures, pH levels, and physiological fluid models. The swelling exponent's maximum value was discovered to be 0.5, which suggests that the hydrogel's water diffusion was non-Fickian in nature. The swelling ratio was found to rise with rising temperature and to have a lower value than that at room temperature. It was also proven that elevating the pH of the medium from 1 to 7 improved the PSA/CMF hydrogels' swelling response. The swelling behaviour of PSA/CMF hydrogels was also investigated as the concentration of CMF rose from 0.2 to 1%. The equilibrium water content, swelling kinetics, and water transport mechanisms were all investigated. The Flory–Rehner equation was applied to determine crosslinking density, polymer mesh size, and molecular weight between crosslinks.
4,500원
18.
2024.04
구독 인증기관 무료, 개인회원 유료
Study on the controlled release properties of modified multi‑walled carbon nanotubes on sulforaphane
Sulforaphane is a naturally occurring active substance found in vegetables that is known for its potential in preventing and treating cancer. This compound has demonstrated promising effects in inhibiting the growth of various types of cancer, including esophageal, lung, colon, breast, and liver cancer. However, its instability towards pH and heat limits its application in the medical and food industries. To address this challenge, novel drug delivery systems have been developed to improve the stability and efficacy of sulforaphane, making it a more suitable candidate for clinical use in cancer research. In this study, nanocomposite materials were prepared using multi-walled carbon nanotubes (MWCNTs) and chitosan (CS) as base materials, with polydopamine (PDA) acting as a bridge material. The synthesized composite materials were used as drug carriers for the release of sulforaphane. The results of the study showed that the drug loading increased with an increase in the concentration of sulforaphane, indicating that the nanocomposite materials were effective in delivering and releasing the drug. Moreover, a positive correlation was observed between the drug loading and the thickness of the PDA layer. These findings suggest that the use of MWCNTs, CS, and PDA in the development of drug delivery systems can enhance the stability and efficacy of sulforaphane, potentially leading to improved cancer treatment outcomes.
4,000원
19.
2024.04
구독 인증기관·개인회원 무료
20.
2024.04
구독 인증기관 무료, 개인회원 유료
Xuan Minh Vu, Thi My Hanh Le, Van Cuong Bui, Tuan Dung Nguyen, D. D. Hrynshpan, Van Thuan Le, Dai Lam Tran, Thi Phuong Lan Nguyen, Thi Lan Pham
Activated carbon (AC) is a versatile and extensively employed adsorbent in environmental remediation. It possesses distinct properties that can be enhanced to selectively target specific pollutants through modifications, including chemical impregnation or incorporation into composite materials. In this study, porous calcium alginate beads (PCAB) were synthesized by incorporating AC and natural alginate through ion gelation in a Ca(II) ion-containing solution, with the addition of sodium lauryl sulfate as a surfactant. The prepared PCAB was tested for Cu(II) removal. PCAB exhibited a spherical shape with higher porosity and surface area (160.19 m2. g−1) compared to calcium alginate beads (CAB) (0.04 m2. g−1). The adsorption kinetics followed the pseudo-first-order model for PCAB and the pseudo-second-order model for CAB. The Langmuir isotherm model provided the best fit for adsorption on PCAB, while the Freundlich model was suitable for CAB. Notably, PCAB demonstrated a maximum adsorption capacity of 75.54 mg.g−1, significantly higher than CAB's capacity of 9.16 mg. g−1. Desorption studies demonstrated that 0.1 M CaCl2 exhibited the highest efficiency (90%) in desorbing Cu(II) ions from PCAB, followed by 0.1 M HCl and 0.1 M NaCl. PCAB showed efficient reusability for up to four consecutive adsorption– desorption cycles. The fixed-bed column experiment confirmed the match with the Thomas model to the breakthrough curves with qTH of 120.12 mg.g−1 and 68.03 mg.g−1 at a flow rate of 1 mL.min−1 and 2 mL.min−1, respectively. This study indicated that PCAB could be an effective adsorbent for Cu(II) removal, offering insights for further application and design considerations.
4,600원
1
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