전해 이온화와 자외선광을 이용한 사파이어 화학기계적 연마의 재료제거 효율 향상에 관한 기초 연구

박성현(Seonghyun Park),이현섭(Hyunseop Lee) 한국트라이볼로지학회 2021 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.37 No.6

Chemical mechanical polishing (CMP) is a key technology used for the global planarization of thin films in semiconductor production and smoothing the surface of substrate materials. CMP is a type of hybrid process using a material removal mechanism that forms a chemically reacted layer on the surface of a material owing to chemical elements included in a slurry and mechanically removes the chemically reacted layer using abrasive particles. Sapphire is known as a material that requires considerable time to remove materials through CMP owing to its high hardness and chemical stability. This study introduces a technology using electrolytic ionization and ultraviolet (UV) light in sapphire CMP and compares it with the existing CMP method from the perspective of the material removal rate (MRR). The technology proposed in the study experimentally confirms that the MRR of sapphire CMP can be increased by approximately 29.9, which is judged as a result of the generation of hydroxyl radicals (·OH) in the slurry. In the future, studies from various perspectives, such as the material removal mechanism and surface chemical reaction analysis of CMP technology using electrolytic ionization and UV, are required, and a tribological approach is also required to understand the mechanical removal of chemically reacted layers.

Development of a hazardous material selection procedure for the chemical accident response manual

이광희,유병길,조형태,박찬호,조성현,박삼배,문일 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.3

After the accidental hydrogen-fluoride leak in Gu-mi city, Korea, the Korean government revised its laws on chemical management. The hazardous chemical management laws were strengthened to meet the legal standards, and now the selection of Accident Precaution Chemicals (APCs) is required. This study introduces a novel hazardous material selection procedure for industrial chemical management. The proposed method consists of screening, scoring, rating, and selection procedures. Among the 4,994 hazardous chemicals in the database, 1,362 chemicals were selected through the screening process. The selected chemicals were classified as flammable, explosive/reactive, and toxic materials, and in the final step, flash point, heat of combustion, and toxicity of these chemicals were considered in chemical ratings. According to the ratings, 100 toxic materials were selected and used to modify the safety management manual development software, currently used in Korean companies that deal with hazardous chemicals. The developed algorithm and software are expected to greatly aid plants that deal with hazardous materials.

Effect of Substitution of Chicken Breast for Alaska Pollack on Physico-chemical Characteristics and Quality in Surimi-like Materials Contained Different Cryoprotectants

진상근,허선진,최영준 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.2

Surimi-like samples were divided into four groups (C, surimi-like material made from Alaska Pollack with all cryoprotectant ingredients; T1, surimi-like material made from chicken breast with sugar and a sorbitol-free cryoprotectant; T2,surimi-like material made from chicken breast with a sugar-free cryoprotectant; T3, surimi-like material made from chicken breast with all cryoprotectant ingredients). Water and protein content were lower in Alaska Pollack surimi-like material (C)than those in chicken breast surimi-like material. Centrifuge loss and cooking loss were higher in C than those in chicken breast surimi-like material. Lipid oxidation (thiobarbituric acid reactive substances) was lower in T3 than others during storage. In a sensory evaluation, overall acceptability was significantly higher in C than those in other samples during storage. As a result, we found that the raw material composition (Alaska Pollack or chicken breast) had a large influence on the physico-chemical characteristics and quality of surimi-like materials, whereas cryoprotectant composition may have less influence on the physico-chemical characteristics and quality of surimi-like materials.

Effect of Substitution of Chicken Breast for Alaska Pollack on Physico-chemical Characteristics and Quality in Surimi-like Materials Contained Different Cryoprotectants

Jin, Sang-Keun,Choi, Young-Jun,Hur, Sun-Jin Korean Society for Food Science of Animal Resource 2011 한국축산식품학회지 Vol.31 No.2

Surimi-like samples were divided into four groups (C, surimi-like material made from Alaska Pollack with all cryoprotectant ingredients; T1, surimi-like material made from chicken breast with sugar and a sorbitol-free cryoprotectant; T2, surimi-like material made from chicken breast with a sugar-free cryoprotectant; T3, surimi-like material made from chicken breast with all cryoprotectant ingredients). Water and protein content were lower in Alaska Pollack surimi-like material (C) than those in chicken breast surimi-like material. Centrifuge loss and cooking loss were higher in C than those in chicken breast surimi-like material. Lipid oxidation (thiobarbituric acid reactive substances) was lower in T3 than others during storage. In a sensory evaluation, overall acceptability was significantly higher in C than those in other samples during storage. As a result, we found that the raw material composition (Alaska Pollack or chicken breast) had a large influence on the physico-chemical characteristics and quality of surimi-like materials, whereas cryoprotectant composition may have less influence on the physico-chemical characteristics and quality of surimi-like materials.

Effect of Substitution of Chicken Breast for Alaska Pollack on Physico-chemical Characteristics and Quality in Surimi-Like Materials Contained Different Cryoprotectants

Sang Keun Jin,Young Jun Choi,Sun Jin Hur 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.2

Surimi-like samples were divided into four groups (C, surimi-like material made from Alaska Pollack with all cryoprotectant ingredients; T1, surimi-like material made from chicken breast with sugar and a sorbitol-free cryoprotectant; T2, surimi-like material made from chicken breast with a sugar-free cryoprotectant; T3, surimi-like material made from chicken breast with all cryoprotectant ingredients). Water and protein content were lower in Alaska Pollack surimi-like material (C) than those in chicken breast surimi-like material. Centrifuge loss and cooking loss were higher in C than those in chicken breast surimi-like material. Lipid oxidation (thiobarbituric acid reactive substances) was lower in T3 than others during storage. In a sensory evaluation, overall acceptability was significantly higher in C than those in other samples during storage. As a result, we found that the raw material composition (Alaska Pollack or chicken breast) had a large influence on the physico-chemical characteristics and quality of surimi-like materials, whereas cryoprotectant composition may have less influence on the physico-chemical characteristics and quality of surimi-like materials.

초등학교 6학년 학생들의 화학물질에 대한 이해도 조사

최봉윤,김성규,공영태 이화여자대학교 교과교육연구소 2009 교과교육학연구 Vol.13 No.2

The purpose of this research is to survey an understanding of chemical materials among sixth grade students. This research involved a total of 278 students from six classes in six elementary schools in the metropolitan city of Ulsan. The results of the research are as follows. The students were generally able to recognize the outer appearance of salt, starch, vinegar, alcohol and acetone, while a recognition of copper sulfate and sodium hydroxide appeared to be low. Regarding physical and chemical properties, an understanding of the salt and starch was high, but an understanding of the vinegar, alcohol, copper sulfate, acetone, sodium hydroxide and hydrochloric acid was relatively low. With the exception of the starch and the hydrochloric acid, the students displayed a high level of understanding of chemical materials usage. In terms of the degree of danger, the students thought that the salt was safe, but in the case of the starch and the vinegar, they were not well aware of the degree of danger for either one. Most students indicated that alcohol, copper sulfate, acetone, sodium hydroxide, and hydrochloric acid solution were dangerous. Treatment of the chemical waste was conducted according to the teacher's instructions, and most students claimed that they had collected eight different kinds of chemical materials. The students also indicated that they knew how to treat salt, starch, vinegar, and acetone from daily experience, while treatment of alcohol, copper sulfate, sodium hydroxide, and hydrochloric acid had been learned in the classroom. Findings of the current study indicate that the teacher's directions during the experimentation and the study of chemical materials in the laboratory were the most important factors. This may be due to the fact that the students always followed the instructions and guidance of their teachers. It is highly recommended that teachers properly understand the methods of controlling the chemical materials and guide students properly. 본 연구에서는 현행 초등학교 과학교과서 물질영역에서 다루고 있는 8가지 화학물질을 선정하여 초등학교 6학년 학생들을 대상으로 1) 겉보기 성질에 대한 이해 2) 물리·화학적 성질에 대한 이해 3) 용도에 대한 이해 4) 화학물질의 안전에 대한 이해 5) 실험 후 화학물질 처리 실태 6) 화학 물질을 알게 된 경로를 살펴봄으로써 화학물질에 대해 얼마나 이해하고 있는지를 알아보았다. 이번 연구에서 얻어진 자료를 바탕으로 화학물질에 대한 관심을 가지고 과학 교수·학습의 방안 모색에 도움이 되고자 한다. 본 연구의 결과를 요약하면 다음과 같다. 겉보기 성질과 물리·화학적 성질은 일상생활 속에서 쉽게 접할 수 있는 소금, 녹말, 식초, 알코올, 아세톤 등은 아동들이 잘 이해하고 있었다. 이에 비하여 생활 속에서 흔히 볼 수 없었고 배운 지가 오래 되었다고 생각되는 황산구리, 묽은 수산화나트륨, 묽은 염산 등은 잘 모르는 것으로 나타났다. 녹말, 염산을 제외하고 용도에 대해 잘 알고 있었다. 위험 인식 정도에서는 먹을 수 있고 친근하게 사용하는 물질은 대체적으로 안전하다고 생각하고 있는 반면, 실험실에서만 주로 다루어지는 물질들은 위험하다고 생각하고 있었다. 학생들이 실험 후 화학물질 처리는 대부분 교사의 지시에 따라 처리하였으며 또한 해당 물질의 물리·화학적인 성질에 따라 처리하는 것으로 나타났다. 알게 된 경로에 대해 ‘가정이나 일상생활을 통해 알게 되었다’라고 응답한 물질은 소금, 녹말, 식초, 아세톤이었고, ‘교과서 또는 실험을 통해 알게 되었다’는 물질은 알코올, 황산구리, 묽은 수산화나트륨, 묽은 염산으로 나타났다. 아동들이 실험실에서 경험한 물질이지만 생소하게 느끼는 물질들을 일상생활 속에서 흔히 볼 수 있는 물질들처럼 잘 알 수 있게 물질의 용도에 대해 구체적인 지도를 해야 한다. 또한 반복적인 학습을 위한 교사의 지속적인 지도가 요구된다. 그러면 많은 아동들이 화학물질에 대해 친근감을 느끼고 과학실험에 대한 흥미가 높아지리라 생각된다.

화학물질 유해성에 대한 작업자와 관리자들의 인식

조용민 ( Yong Min Cho ),김희정 ( Hee Jung Kim ),최재욱 ( Jae Wook Choi ) 한국산업위생학회 2012 한국산업보건학회지 Vol.22 No.4

Objectives: In chemical hazard communication, information receiver`s perception is a important factor, but the study on the perception was few. Therefore, this study evaluated the perception of managers and workers group about chemical hazard communication by chemical hazard communication tools that were being used in fields. Methods: 91 managers and 238 workers were surveyed in two companies where use chemicals. All subjects were asked about the comprehensibility and perception for MSDS and GHS Pictograms being used in their workplaces through faceto- face interviews. Results: Most of the respondents knew MSDS, and more than half of the respondents had used MSDS once or more per year. The level of use to find the information on chemicals with MSDS was higher in the managers in comparison with workers. Also, the managers could understand and find the information on MSDS easier(p < 0.05). In the question asking the meaning of GHS Pictograms, the managers responded more correctly, as well(p < 0.05). 86.8% of the managers and 62.6% of the workers were conscious of the possible health hazards of chemicals that they could be exposed at work. However, among the respondents conscious of the health hazards, only less than 70% were well aware of the contents of the health hazards correctly. Conclusions: In chemical hazard communication, it is very important to evaluate whether information receiver have proper and correct knowledge and perception or not and actions based on the evaluations as well as provide correct information.

전자재료 표면의 무결함 연마를 위한 화학기계적 균형

정해도(Hae-Do Jeong),이창석(Chang-Suk Lee),김지윤(Ji-Yoon Kim) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.1

Chemical mechanical polishing(CMP) technology is faced with the challenge of processing new electronic materials. This paper focuses on the balance between chemical and mechanical reactions in the CMP process that is required to cope with a variety of electronic materials. The material properties were classified into the following categories: easy to abrade(ETA), difficult to abrade(DTA), easy to react(ETR) and difficult to react(DTR). The chemical and mechanical balance for the representative ETA-ETR, DTA-ETR, ETA-DTR and DTA-DTR materials was considered for defect-free surfaces. This paper suggests the suitable polishing methods and examples for each electronic material.

국내 트리클로로에틸렌의 물질흐름분석

박준철(Jun Chul Park),황용우(Yong Woo Hwang),김준범(Jun Beum Kim),김영운(Young Woon Kim) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.4

목적 : 물질흐름분석을 통하여 그룹 1 발암물질 중 배출량이 가장 많은 트리클로로에틸렌의 국내 흐름을 파악한 후, 효율적인 화학물질 관리 및 배출량 저감방안 수립을 위한 기초자료를 제공하고자 하였다. 방법 : 본 연구에서는 2014년 국내 트리클로로에틸렌의 물질흐름분석을 실시하였다. 물질흐름도는 STAN 2.6 소프트웨어를 사용하여 나타내었다. 연구 대상 물질의 지역별・산업별 흐름을 분석하여 각 흐름의 특성을 파악한 후, 배출량 저감 방안을 제시하였다. 결과 및 토의 : 트리클로로에틸렌은 수도권에서 79.8%가 사용되었고, 기타 기계 및 장비 제조업에서 45.6%, 금속가공제품 제조업에서 29.4% 사용되었으며, 고무제품 및 플라스틱제품 제조업에서 42.0%, 1차 금속 제조업에서 26.8% 배출되었다. 기업 규모별 배출량 분석 결과 대기업에서 전체 배출량의 3.9%, 중견기업에서 전체 배출량의 61.6%, 중소기업에서 전체 배출량의 34.5%를 배출하였다. 트리클로로에틸렌은 사용량에 비해 배출량이 많았으며, 다양한 업종 및 지역에서 사용되었다. 결론 : 트리클로로에틸렌은 사용량에 비해 많은 양이 배출되었는데, 소규모 사업장의 화학물질의 관리가 미흡한 것으로 조사되었다. 물질흐름분석 결과를 기초자료로 활용하여 화학물질의 배출 저감 방안으로 화학물질의 위험성 및 대체물질 홍보, 기업 간 교류 시스템 도입, 발암물질 배출 총량제 도입, 배출저감계획서의 의무 이행, 배출저감 인센티브제도 고려를 제시하였고, 위험성 개선 방안으로 위험성 데이터베이스 구축을 제시하였다. Objectives : According to the material flow analysis, the domestic flow of trichloroethylene with the highest emission among carcinogens in group 1 was determined. The purpose of this study is to provide basic data for efficient chemical management and establish measures to reduce emissions. Methods : In this study, the material flow analysis of trichloroethylene was analyzed in Korea in 2014. The material flow chart was presented using STAN 2.6 software. The flow of trichloroethylene by region and industry was analyzed to identify the characteristics of each flow, and the emission reduction method was presented. Results and Discussion : Trichloroethylene was used up to 79.8% in the Seoul metropolitan area, 45.6% in the manufacturing of other machinery and equipment, and 29.4% in the manufacturing of fabricated metal products except machinery and furniture. Trichloroethylene was emitted 42.0% in the manufacturing of rubber and plastics products and 26.8% in the manufacturing of primary metals. The analysis of emissions by company size resulted in 3.9% of total emissions from large companies, 61.6% from mid-sized companies, and 34.5% from small-sized companies. Trichloroethylene was used in various industries and regions, with higher emissions compared to its use. Conclusions : Trichloroethylene has been emitted in large quantities relative to its usage. The study found that the management of chemicals in small businesses was insufficient. This result of the material flow analysis is used as basic data to reduce emissions of chemicals. The result of the study helps to recognize the risk of chemicals and suggest alternative materials, introduce inter-company information and expert exchange system, introduce a total amount of carcinogens emission system, implement duties in the emission reduction plan, and consider emission reduction incentives. In addition, measures to improve risk are proposed to establish risk-based database.

Edge-Functionalized Graphene Nanoribbon Chemical Sensor: Comparison with Carbon Nanotube and Graphene

Cho, Kyeong Min,Cho, Soo-Yeon,Chong, Sanggyu,Koh, Hyeong-Jun,Kim, Dae Woo,Kim, Jihan,Jung, Hee-Tae American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.49

<P>With growing focus on the use of carbon nanomaterials in chemical sensors, one-dimensional graphene nanoribbon (GNR) has become one of the most attractive channel materials, owing to its enhanced conductance fluctuation by quantum confinement effects and dense, abundant edge sites. Due to the narrow width of a basal plane with one-dimensional morphology, chemical modification of edge sites would greatly affect the electrical channel properties of a GNR. Here, we demonstrate for the first time that chemically functionalizing the edge sites with aminopropylsilane (APS) molecules can significantly enhance the sensing performance of the GNR sensor. The resulting APS-functionalized GNR has a sensitivity ((Δ<I>R</I>/<I>R</I><SUB>b</SUB>)<SUB>max</SUB>) of ∼30% at 0.125 ppm nitrogen dioxide (NO<SUB>2</SUB>) and an ultrafast response time (∼6 s), which are, respectively, 7- and 15-fold enhancements compared to a pristine GNR sensor. This is the fastest and most sensitive gas-sensing performance of all GNR sensors reported. To demonstrate the superiority of the GNR-APS sensor, we compare its sensing performance with that of APS-functionalized carbon nanotube (CNT) and reduced graphene oxide (rGO) sensors prepared in identical synthesis conditions. Very interestingly, the GNR-APS sensor exhibited 30- and 93-fold enhanced sensitivity compared to the CNT-APS and rGO-APS sensors. This might be attributed to highly active edge sites with superior chemical reactivity, which are not present in CNT and rGO materials. Density functional theory clearly shows that the greatly enhanced gas response of GNR with edge functionalization can be attributed to the higher electron densities in the highest occupied molecular orbital levels of GNR-APS and incorporation of additional adsorption sites. This finding is the first demonstration of the importance of edge functionalization of GNR for chemical sensors.</P> [FIG OMISSION]</BR>