Silicon-Based Anode with High Capacity and Performance Produced by Magnesiothermic Coreduction of Silicon Dioxide and Hexachlorobenzene

Ma, Kai The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.3

Silicon (Si) has been considered as a promising anode material because of its abundant reserves in nature, low lithium ion (Li⁺) intercalation/de-intercalation potential (below 0.5 V vs. Li/Li⁺) and high theoretical capacity of 4200 mA h/g. In this paper, we prepared a silicon-based (Si-based) anode material containing a small amount of silicon carbide by using magnesiothermic coreduction of silica and hexachlorobenzene. Because of good conductivity of silicon carbide, the cycle performance of the silicon-based anode materials containing few silicon carbide is greatly improved compared with pure silicon. The raw materials were formulated according to a silicon-carbon molar ratio of 10:0, 10:1, 10:2 and 10:3, and the obtained products were purified and tested for their electrochemical properties. After 1000 cycles, the specific capacities of the materials with silicon-carbon molar ratios of 10:0, 10:1, 10:2 and 10:3 were still up to 412.3 mA h/g, 970.3 mA h/g, 875.0 mA h/g and 788.6 mA h/g, respectively. Although most of the added carbon reacted with silicon to form silicon carbide, because of the good conductivity of silicon carbide, the cycle performance of silicon-based anode materials was significantly better than that of pure silicon.

Current Status of Thin Film Silicon Solar Cells for High Efficiency

Chonghoon Shin,Youn-Jung Lee,Jinjoo Park,Sunbo Kim,Hyeongsik Park,Sangho Kim,Junhee Jung,Junsin Yi 한국태양광발전학회 2017 Current Photovoltaic Research Vol.5 No.4

The researches on the silicon-based thin films are being actively carried out. The silicon-based thin films can be made as amorphous, microcrystalline and mixed phase and it is known that the optical bandgap can be controlled accordingly. They are suitable materials for the fabrication of single junction, tandem and triple junction solar cells. It can be used as a doping layer through the bonding of boron and phosphorus. The carbon and oxygen can bond with silicon to form a wide range of optical gap. Also, The optical gap of hydrogenated amorphous silicon germanium can be lower than that of silicon. By controlling the optical gaps, it is possible to fabricate multi-junction thin film silicon solar cells with high efficiencies which can be promising photovoltaic devices.

실리콘에 의한 말초혈액 단핵구의 아세포 형성능 및 단핵세포의 interleukin-1β와 tumor necrosis factor-α의 분비효과

한만욱,장익수,안상태 大韓成形外科學會 1998 Archives of Plastic Surgery Vol.25 No.7

Although there are numerous reviews of clinical and epidemiologic data, there has been no critical analysis of silicone immunology. The purpose of this study is to identify human celluar immune reaction to silicone through mononuclear cell blastogenesis as well as by measuring IL-1βand TNF-α released from human monocyte/macrophage incubated with silicone in vitro. In the study, total 14 healthy volunteers participated in the experiment as blood donors. in the peripheral blood mononuclear cell blastogenesis assay, one control group and three experimental groups were designed. The three experimental groups were composed of a silicone treated group, a silicone/phytohemagglutinin treated group, and a phytohemagglutinin treated group. The peripheral blood mononuclear cells were isolated with the Ficoll-Hypaque gradient method, and they were incubated for 72 hours. The proliferation of the peripheral blood mononuclear cells was measured with the [³H]-thymidme uptake. In the cytokine assay of monocyte stimulated by silicone, human monocyte was isolated from the peripheral blood mononuclear cells through the magnetic cell sorting(MACS) method. One control group and three experimental groups were designed also in the experiment. The experimental groups were composed of a silicone treated group, a silicone/lipopolysaccharide treated group, and a lipopolysaccharide treated group. The monocytes of each group were incubated for 1,3,6,24 and 48 hours. The supernatants were preserved at -20℃ to measure IL-1βand TNF-α with ELISA. Statistical analysis was done by two-way ANOVA and Scheffe test(p < 0.05). In the peripheral blood mononuclear cell blastogenesis study, no statistical difference was found either between the silicon treated group and the control group, or between the silicone/phytohemagglutinin treated group and the phytohemagglutinin treated group. The silicone treated group had higher IL-1βlevel than the control group 1 hour and 3 horus(p < 0.05), and the silicone/LPS treated group and had higher IL-1βlevel than the LPS treated group at 1 hour(p < 0.05). However the TNF-αlevel had shown statistical difference neither between the silicone treated group and control group nor between the silicone/LPS treated group and the LPS treated group at any time. In conclusion, IL-1β was released from the human monocyte/macrophage induced by silicione, and silicone did not induce peripheral blood mononuclear cell blastogenesis. It has been known that IL-1βcan induce the chemotaxis of T lymphocyte-subpopulation and T cell infiltration in tissue. Therefore the results of this experiments are regarded as an evidence of silicone-induced inflammation and tissue destruction such as rheumatic disease.

소수성 모노머들을 포함한 콘택트렌즈의 특성에 관한 연구

예기훈,김태훈,성아영 한국안광학회 2008 한국안광학회지 Vol.13 No.3

목적: 본 연구에서는 HEMA(2-Hydroxyethyl methacrylate)/Silicone 기본 조합에 각각 BMA(Butyl methacrylate)와 MMA(Methyl methacrylate)를 혼합하여 콘택트렌즈의 재료로 사용한 후, 각각의 물리적 특성을 비교하였다. 방법: 캐스트 몰드 법을 이용하여 각각의 렌즈를 제조 하였으며, 각 시료의 물리적 특성에 대한 평균값을 사용하여 분석 하였다. 결과: HEMA/silicone/BMA 조합의 경우, 함수율은 24.69%에서 29.26%, 인장강도는 0.109kgf에서 0.263kgf 의 분포를 나타내었다. HEMA/silicone/MMA 조합의 경우, 팽윤율은 13.56%에서 14.83%, 함수율은 25.61%에서 29.33%, 인장강도는 0.107kgf에서 0.286kgf의 분포를 나타내었다. 결론: 두 조합은 HEMA/silicone(0.20%~11.50%) 의 기본 조합에서 BMA(5.15%)와 MMA(5.15%)를 일정량 첨가한 것으로 두 경우 모두에서 BMA의 양과 MMA의 양이 상대적으로 감소할수록 팽윤율과 함수율이 증가하는 경향을 보였다. HEMA/silicone/MMA 조합의 경우, 인장 강도는 silicone의 비율이 증가할수록 4-MMA 시료까지는 다소 증가하는 경향을, HEMA/silicone/BMA 조합의 경우 , 인장강도는 silicone의 비율이 증가할수록 감소하는 경향을 나타내었다. Purpose: In this study, we compared the physical properties of the compositions that were mixed with basic materials of HEMA (2-Hydroxyethyl methacrylate)/Silicone and BMA (Butyl methacrylate), MMA (Methyl methacrylate) by making the silicone contact lens. Method: Each sample of contact lenses was fabricated by cast mould method. We analyzed results by using average values of physical property of each sample. Results: In the composition of HEMA/Silicone/BMA, water contents of samples showed the value from 24.69% to 29.26%. Ultimate strength of samples showed the value from 0.109 kgf to 0.263 kgf. In the composition of HEMA/ Silicone/MMA, swelling ratio of samples showed the value from 13.56% to 14.83%. Water contents of samples showed the value from 25.61% to 29.33%. Ultimate strength of samples showed the value from 0.107 kgf to 0.286 kgf. Conclusions: The compositions of percents of silicone were ranged from 0.20% to 11.50% and the composition percent of BMA and MMA was 5.15% in total. Swelling ratio and water contents increased with decreasing of BMA (Butyl methacrylate) and MMA (Methyl methacrylate) percent. In the composition of HEMA/Silicone/MMA, the values of ultimate strength increased with increasing of silicone percent to 4-MMA sample. In the composition of HEMA/Silicone/BMA, the values of ultimate strength decreased with increasing of silicone percent.

CNT를 첨가한 Silicon/Carbon 음극소재의 전기화학적 특성

정민지 ( Min Zy Jung ),박지용 ( Ji Yong Park ),이종대 ( Jong Dae Lee ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.1

Silicon/Carbon/CNT, Anode material, Carbon nanotube, Magnesiothermic re실리콘의 부피팽창과 낮은 전기전도도를 개선하기 위하여 Silicon/Carbon/CNT 복합체를 제조하였다. Silicon/Carbon/CNT 합성물은 SBA-15를 합성한 후, 마그네슘 열 환원 반응으로 Silicon/MgO를 제조하여 Phenolic resin과 CNT를 첨가하여 탄화하는 과정을 통해 합성하였다. 제조된 Silicon/Carbon/CNT 합성물은 XRD, SEM, BET, EDS를 통해 특성을 분석하였다. 본 연구에서는 충방전, 사이클, 순환전압전류, 임피던스 테스트를 통해 CNT 첨가량에 따른 전기화학적 효과를 조사하였다. LiPF6 (EC:DMC:EMC=1 :1 :1 vol%) 전해액에서 Silicon/Carbon/CNT 음극활물질을 사용하여 제조한 코인셀은 CNT 함량이 7 wt% 일 때 1,718 mAh/g으로 높은 용량을 나타내었다. 코인셀의 사이클 성능은 CNT첨가량이 증가할수록 개선되었다. 11 wt%의 CNT를 첨가한 Silicon/Carbon/CNT 음극은 두 번째 사이클 이후 83%의 높은 용량 보존율을 나타냄을 알 수 있었다.duction, Lithium ion battery Silicon/Carbon/CNT composites as anode materials for lithium-ion batteries were synthesized to overcome the large volume change during lithium alloying-de alloying process and low electrical conductivity. Silicon/Carbon/CNT composites were prepared by the fabrication processes including the synthesis of SBA-15, magnesiothermic reduction of SBA-15 to obtain Si/MgO by ball milling, carbonization of phenolic resin with CNT and HCl etching. The prepared Silicon/ Carbon/CNT composites were analysed by XRD, SEM, BET and EDS. In this study, the electrochemical effect of CNT content to improve the capacity and cycle performance was investigated by charge/discharge, cycle, cyclic voltammetry and impedance tests. The coin cell using Silicon/Carbon/CNT composite (Si:CNT=93:7 in weight) in the electrolyte of LiPF6 dissolved in organic solvents (EC:DMC:EMC=1:1:1 vol%) has better capacity (1718 mAh/g) than those of other composition coin cells. The cycle performance of coin cell was improved as CNT content was increased. It is found that the coin cell (Si:CNT=89:11 in weight) has best capacity retension (83%) after 2nd cycle.

Effect of Defect Densities and Band Offsets on Carrier Transport Mechanisms in Mixed phase Silicon/Crystalline Silicon Heterojunction

이준신,Vinh Ai Dao,김경해,김영국,Duy Nguyen Van,Zhenghai Jin 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

Thin-film silicon/crystaline silicon heterojunction-type solar cels, combining the low-cost, low- temperature and light-weight of thin-film silicon with the high efficiency and high stability of crystaline silicon (c-Si), are studied widely due to the increased need for terrestrial and satelite applications. A major aspect when dealing with thin-film silicon/crystaline silicon heterojunction solar cels is quality of the silicon film-crystaline silicon hetero-interface. In this study, the carrier transport mechanisms in mixed phase (amorphous and microcrystaline) thin-film silicon/p type crystaline silicon heterojunction for various thin-film thicknesses and SiH4/H2 ratios are investi- gated. The electrical properties are strongly affected by the defect state distribution and the band offset at the hetero-interface. Two carrier transport mechanisms are recognized. The recombination process involving the interface states on the thin-film silicon side dominates at low forward bias (V < 0.4 V), whereas multi-step tunneling capture emission (MTCE) dominates at the high forward bias (0.4 < V < 0.8 V).

Effect of wafer resistivity and HF concentration on the formation of vertically aligned porous silicon

Yonughwan Lee,Jonghyuck Lee,Yonggun Shul,임상우 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.1

In this study, the mechanism of vertically aligned porous silicon formation was examined. Silicon wafers with various resistivities and electrolytes containing different HF concentrations were used to explain porous silicon formation by the reaction at the silicon/electrolyte interface. Total pore volume increased proportionally to the current applied and anodization time. As the concentration of HF increased, pore depth and total pore volume formed in silicon anodization increased, then decreased beyond the optimum point. At a given applied current, total pore volume formed by anodization increased with an increase in resistivity of silicon wafer, but then decreased. From the mechanism of silicon etching and schematic isoetch contour of silicon suggested in this study, it is concluded that the formation of porous silicon is determined by an accumulation of F near the silicon/electrolyte interface in silicon anodization. # 2007 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

백인의 상처분장과 노인분장에 활용할 수 있는 실리콘의 조색방법

김숭현,이윤진,이금희,김기영 대한미용학회 2011 대한미용학회지 Vol.7 No.2

According to the development of the special make-up industry, silicons are used widely as special make-up materials. silicone have a advantage for expression a variety of skin colors and give the delicacy and reality in the description of the character often expressed in the makeup of wounds and old people are needed. So that, in this study expression methode of incision wound skin and old age special make-up in white people were investigated by silicon’s colorants combination. 10 White people’s skin color (L*, a*, b*) were measured by chromameter, and the colorants of beige, permanent yellow light, carmine and cobalt blue were mixed at different concentration. The chromaticity’s change and similarity of the silicon was observed by the thickness. Colorants combined silicons were prepared and tried to wound and old age special make-up on a face of white people. As a result, the value of lightness on the forehead and cheek L*=60.4 and 60.1, the value of redness a*=13.4 and 14.4, and the value of yellowness b*=12.6 and 11.7 in the 10 participants. Optimal mixing ratio was beige 9.21 g : carmine 0.66 g : cobalt blue 0.13 g. And it was very similar to the real skin color, so this ratio was used for preparation of silicon piece. The thicker of the silicon piece was more the darker than thinner, and attaching the 2 mm silicon piece on the skin of a participant, the color was very similar and it was difficult to observe the difference with the naked eye. When being applied to the makeup of wounds, the silicon expressed the swollen skin surface caused by injuries and the incised wound realistically without the sense of difference in the edge. When being applied to the makeup of old people, the silicon expressed the feature of the aging skin such as the detailed wrinkle on the forehead, the drooping under the eye, and the wrinkle around the mouth delicately and realistically. In conclusion, as the thickness of the silicon influences the chromaticity, and combination of silicon and colorants could be very useful in the special makeup such as of incision wound skin and old people.

실리콘을 소재로 한 장신구 연구

이광선 ( Kwang Sun Lee ) 한국기초조형학회 2014 기초조형학연구 Vol.15 No.6

지난 세기 50년대 이후 장신구계에 등장한 현대 장신구의 특징 중의 하나는 장신구가 다양한 재료를 사용한다는 점이다. 그때까지 부각되지 않던 소재의 관점은 이제 장신구디자인에서 전면에 나타나고 장신구는 이 관점에서 만들어졌으며. 그 결과 새로운 장신구들이 만들어진다. 실리콘은 그런 소재 중의 하나이다. 이 연구는 실리콘이 어떤 속성으로 인해 현대 장신구의 신소재로 이용되는지, 지금까지 어떤 실리콘 장신구들이 만들어졌는지, 마지막으로 지금까지의 실리콘 장신구와는 다른, 실리콘의 조형 가능성에 대해서 분석하고자 했다. 20세기 초에 인공적으로 만들어진 실리콘은 무한한 조형가능성을 가지고 있으며 신체에 유해하지 않고 원하는 칼라를 낼 수 있다. 무엇보다 비교적 가격이 저렴하다. 이런 속성들에 의해서 실리콘은 이미 사회의 다양한 분야에서 광범위하게 사용되고 있다. 그러나 실리콘이 장신구계에서 소재로 사용된 시점은 그다지 오래되지 않았으며 그런 까닭에 거의 모든 실리콘 장신구들은 단순히 자연이나 문화에 존재하는 사물들을 복제하는 식으로 만들어졌다. 따라서 이것들은 장신구의 좋은 미적 질을 보여주지 못한다. 이런 한계는 극복될 수 있는데, 그렇기 위해서는 왜 실리콘이 사용되어야만 하는지에 대한 물음을 고려해서 심미적 컨셉을 발전시켜야만 한다. 이에 대한 예로 신체와의 관계성을 주제로 삼은 실리콘 장신구를 분석해서 실리콘의 물성을 극대화하면서 다른 소재와의 결합을 통해 실리콘이 가진 소재적 한계성을 넘어서 수공예적 기술과 조형적 컨셉 그리고 심미성을 보여주는 실리콘 장신구의 또 다른 조형가능성을 제시했다. One of some features of modern jewelry that has come into the jewelry scene since 1950sisthat it started to use more materials. Therefore, the aspect of the material that had been neglected until that time, was moved in the foreground of the jewelry design and the jewelry was considered from this aspect and produced. Thus, new forms of jewerly began to be made. Silicon is one of such materials. This study attempts to analyse what features it has, what made it used as a material of modern jewelry, which silicon jewels have now been produced, and which design options from silicon for jewelry there can be. Silicon, which was produced artificially at the beginning of the 20th century, has unlimited design possibilities, has no harm to human body, can be colored as many. Above all, it is cheap. Thanks to these properties, it already finds its enormous uses in various sectors of society. However, it is not until recently that it has been used in the jewelry scene as material, and most of the silicon-jewelry was designed simply to imitate things both in nature and in culture, resulting in unvaried products. In fact, it has unlimited design possibilities and this deficiency in design can be overcome soon. For a lot of artists will develop aesthetic concepts in due consideration of why silicone must be used. If jewelry is to be made from silicone, it has to show both aesthetic design concepts and manual skills of jewelry artist. To make this clear, here is a silicone jewelry analyzed, which takes the variable relationship between the body and the jewelry as aesthetic concept. This analysis shows a new silicone jewelry that exceeds through the combination with the metal the material limit of silicon and simultaneously makes the materiality of silicone clear. This is aresult from the cooperation of craft technique, design concept and aesthetics.

A systematic review of complications associated with nasal augmentation implants: expanded polytetrafluoroethylene (Gore-Tex) versus silicone

Han Le Thuc Hoang,Michael Januszyk,J,Brian Boyd 대한미용의학회 2017 대한미용의학회지 Vol.1 No.2

Background: Augmentation rhinoplasty has been one of the most common cosmetic procedures in Asian population. Silicone is the most widely used nasal augmentation material in Asia. However, in the past few decades, expanded polytetrafluoroethylene (ePTFE, Gore-tex ?? ) has become more popular as an alternative. Objective: In this study, complications associated with each implant aresystematically reviewed. Methods: Heuristic searches of MEDLINE, PubMed, and the Cochrane Library were performed using the keywords “ePTFE”, “Goretex”, “silicone”, and “rhinoplasty” to identify manuscripts for inclusion. The reference lists of these articles were systematically reviewed to further identify relevant articles. Only studies with detailed complication reports (i.e., infection, malposition) were considered. Random effects meta-analysis was performed to calculate the significance of differences in complication rates between silicone and ePTFE. Results: Eighteen studies encompassing a total of 7,759 patients were analyzed, 12 with ePTFE and 6 with silicone. Among studies in which sex was reported, 88.8% of the patients were female. 88.4% of cases in the silicone group were primary, as compared to 78% in the ePTFE group. Overall complications were 5.3% for the ePTFE group and 9.2% for silicone (p<0.05). Infection rate was similar between the two groups, 1.4% for ePTFE versus 1.9% for silicone group (p>0.05). Exposure rate was also similar, 0.7% for silicone and 1.2% for ePTFE (p>0.05). Malposition rates were significantly lower in ePTFE group compared to those receiving silicone implants (2.4% versus 6.8%, p<0.05). Conclusion: Although the gold standard graft material for rhinoplasty remains autologous tissue, implant based rhinoplasty is far more common in Asian populations. Both silicone and ePTFE have acceptable risk profiles when used in selective patients for dorsal augmentation. However, given the additional risks of capsular contracture and implant malposition associated with silicone implants, ePTFE should be considered as a first-line option for implant-based nasal augmentation.