음식물류폐기물폐수의 혐기성 소화에서 바이오가스의 실록산 농도 특성

이채영,이세욱,박수희,허광범,김해룡,이남훈 유기성자원학회 2011 유기물자원화 Vol.19 No.4

Siloxane is an organic silicon compound and is volatilized into the bio gas from anaerobic digestion. It causes failure of gas combustion engines using the bio gas. Siloxane emission characteristics should be identified to provide a proper siloxane control. This study focuses on characterizing siloxane emission in bio gas from an anaerobic digester of food wastewater operating from January to March. The concentrations of total average siloxane and cycle-siloxane D4 were detected to be 9.5 and 4.0 mg siloxane/㎥, respectively. The concentrations of cycle-siloxane and linear-siloxane were resulted in D4>D5>D6 and L4>L3>L5>L2, respectively. The total siloxane concentration was the lowest in January and the highest in March. 실록산은 유기규소화합물로서 혐기성소화조에서 생산되는 바이오가스로 휘발되며, 이러한 실록산은 바이오가스로 이용되는 가스 연소 엔진 고장의 원인이 된다. 따라서, 바이오가스 내의 실록산을 저감시킬 수 있는 방안이 필요하며 우선적으로 실록산의 발생특성에 대한 조사가 필요하다. 이에 본 연구는 음식물류폐기물폐수의 혐기성소화조에서 발생되는 바이오가스에 함유되어 있는 실록산의 농도 특성을 조사하였다. 총 실록산의 농도는 평균적으로 9.5 mg siloxane/㎥로 나타났으며, 고리 구조 D4의 실록산 농도는 4.0 mg siloxane/㎥로 가장 높게 나타났다. 고리구조 및 선형구조 실록산의 농도는 각각D4>D5>D6 및 L4>L3>L5>L2의 순서로 나타났다. 1월 2월 및 3월의 실록산 농도 측정 결과에서 1월의 총 실록산 농도가 가장 낮게 나타났으며, 3월의 총 실록산 농도가 가장 높게 나타났다.

조성 및 실록산 분자 구조에 따른 전자 패키징용 에폭시 기반 실록산/실리카 복합체의 물성 변화 분석

장준호,강동준,임현균,Junho Jang,Dong Jun Kang,Hyeon-Gyun Im 한국분말재료학회 (*구 분말야금학회) 2023 한국분말재료학회지 (KPMI) Vol.30 No.4

Epoxy-based composites find extensive application in electronic packaging due to their excellent processability and insulation properties. However, conventional epoxy-based polymers exhibit limitations in terms of thermal properties and insulation performance. In this study, we develop epoxy-based siloxane/silica composites that enhance the thermal, mechanical, and insulating properties of epoxy resins. This is achieved by employing a sol-gel-synthesized siloxane hybrid and spherical fused silica particles. Herein, we fabricate two types of epoxy-based siloxane/silica composites with different siloxane molecular structures (branched and linear siloxane networks) and investigate the changes in their properties for different compositions (with or without silica particles) and siloxane structures. The presence of a branched siloxane structure results in hardness and low insulating properties, while a linear siloxane structure yields softness and highly insulating properties. Both types of epoxy-based siloxane/silica composites exhibit high thermal stability and low thermal expansion. These properties are considerably improved by incorporating silica particles. We expect that our developed epoxy-based composites to hold significant potential as advanced electronic packaging materials, offering high-performance and robustness.

매립지 특성이 매립가스 내 siloxane 발생에 미치는 영향

남상철,강정희,허광범,이남훈 유기성자원학회 2011 유기물자원화 Vol.19 No.3

유기규소화합물인 siloxane은 물리화학적으로 우수한 특성으로 인하여 화장품이나 세제 등과 같이 우리 생활에서 다양한 제품 형태로 사용된다. 이러한 제품의 사용 후 매립되어 분해되는 과정에서 매립가스에 포함된 siloxane은 매립가스 자원화 시설의 운영 시 악영향을 미친다. 본 연구에서는 국내 여러 매립지 특성에 따른 매립가스 내 실록산 발생특성을 파악하기 위하여 매립연령과 매립폐기물에 따른 siloxane 발생특성을 실록산의 농도, 구조 및 성분별로 고찰하였다. 시간에 따른 실록산 발생특성은 매립종료 전ㆍ후와 각 매립지의 매립연령별로 12개 매립지를 대상으로 검토하였으며, 매립폐기물에 의한 siloxane의 발생특성 변화는 6개 매립지를 대상으로 매립폐기물의 발생원 및 물리적 조성의 비율과 siloxane 농도를 비교하였다. 매립가스 내 total-siloxane의 농도는 평균 6.75 mg/m3 이었으며, cyclic-siloxane이 이 중 93% 이상을 차지한 것으로 나타났다. 성분별 실록산은 매립연령과 관계없이 D4 및 D5가 순서대로 가장 높은 비율을 차지하였다. 본 연구에서 매립폐기물의 종류(조성)가 실록산 발생에 미치는 영향은 확인할 수 없었으나, total-siloxane 및 cyclic-siloxane의 농도는 매립가스 일차분해모델과 같이 매립연령이 증가함에 따라 감소하는 것으로 나타났다. Siloxane, organo-silicon compound, is used in the various forms of products such as cosmetics and detergents due to its quality physical chemistry attributes. Siloxane included in landfill gas which is caused in the process of decomposing of such products after landfill has imposed negative impacts on the operation of landfill gas utility facilities. The objective of this study was to investigate the siloxane production characteristics depending on the features of various landfill site in Korea so that the analysis was made on the landfilling age and landfill waste by in terms of its concentration, structure and composition. As for the concentration of siloxane depending on time passage, 12 landfill sites were reviewed by landfilling age. As for production attributes change of siloxane by landfill wastes, the source of wastes, physical production ration and siloxane concentration were compared in 6 landfills. The average concentration of total-siloxane within LFG is 6.75 mg/m3 and cyclic-siloxane out of it occupies over 93%. By element, D4 and D5 in order take the highest proportion regardless of total-siloxane concentration and landfilling age. Even though this study is not able to verify the different impact of each kind of wastes on the generation of siloxane, it is confirmed that total-siloxane and cyclic-siloxane decrease in line with the increase of landfilling age as it does in the first order decay model for landfill gas.

Robust siloxane/graphene oxide thin film membranes: Siloxane size adjustment for improved separation performance and flux recovery

Solmaz Valizadeh,Leila Naji,Mohammad Karimi 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

Siloxane/graphene oxide (GO) nanocomposites were synthesized by hydrolysis and condensation of tetraethyl orthosilicate in the presence of GO nanosheets through a sol-gel process. The influence of synthesis parameters on the properties of the siloxane/GO samples was studied and their structural, morphological and physicochemical characteristics were compared using various techniques. Polyether sulfone-supported GO and siloxane/GO thin film membranes were prepared using a pressure-assisted self-assembly method using a dead-end cell, and their separation performance and antifouling ability were evaluated. Siloxane/GOs appeared to have higher interlayer spacing, higher zeta potential and thus higher dispersion stability in aqueous media compared to GO. This gave rise to slower and more uniform sedimentation of the siloxane/GOs during the filtration process and formation of thin film membranes possessing denser and smoother morphology. The porosity, mean pore radius, water contact angle and pure water flux of the prepared membranes were compared. The separation performance of the prepared membranes to remove methylene blue (MB) and penicillin G-procaine (PG-P) from water was evaluated as a function of used GO solution concentration. The antifouling ability of membranes was studied by determining reversible fouling (Rr), irreversible fouling (Rir) resistances and flux recovery ratio (FRR). The siloxane/GO thin film membranes containing larger siloxane network exhibited the highest rejection percentage for MB (~99%) and PG-P (~88%), which were about 40% and 90% higher than that achieved for GO thin film membranes, while the water flux remained as high as 78.1 l·m2h1. Furthermore, these membranes exhibited the highest chlorine resistance, stability under ultrasonication, FRR (89%) and Rr (57%) values, implying higher chemical and mechanical stability, flux recovery capacity and antifouling ability.

실록산 이미드로 개질된 변성 에폭시 수지의 물성

공희진 ( H. J. Gong ),김원호 ( W. Kim ) 한국고무학회 2008 엘라스토머 및 콤포지트 Vol.43 No.1

상용 에폭시 수지의 접착력은 XNBR을 첨가함으로써 달성할 수 있으나 이는 필연적으로 유리전이온도(Tg)의 감소를 수반하여 접착제의 내열성을 저하시킨다. 1,3-bis(3-aminopropyl) tetramethyldisiloxane과 hydroxy phthalic anhydride를 반응시켜 siloxane-imide를 합성하고, 이를 상용 에폭시 수지와 공중합시켜 변성 에폭시 수지를 합성하였다. 변성 에폭시 수지의 siloxane-imide 함량을 결정하기 위하여 접착력 및 유리전이온도를 2관능성 에폭시 수지의 경우와 비교하여 조성비를 정하였다. Siloxane-imide와 공중합된 30% 변성 에폭시 수지는 5% XNBR을 첨가한 경우 0.42 N/mm의 박리 강도와 155℃의 유리전이온도를 나타내어 die-bond용 접착제에 요구되는 물성 값인 0.3 N/mm 이상의 박리 강도와 150℃ 이상의 유리전이온도를 충분히 만족시킴을 알 수 있었다. 변성 에폭시 수지의 내 산성, 내 알칼리성 및 내습성을 평가한 결과 벤젠 링과 이미드 링의 영향으로 산, 염기 조건에서는 상용 에폭시 수지 대비 무게 변화폭이 감소하였지만 수분 조건에서는 무게 변화폭이 증가한 것을 알 수 있었다. 5% XNBR을 첨가한 30% 변성 에폭시 수지의 경우, 인장응력과 신장률이 상용 에폭시 수지 대비 약 220% 향상되었는데 이는 siloxane의 유연한 성질 때문인 것으로 판단된다. Peel strength of epoxy adhesives can be increased by adding some amounts of XNBR. In this case, thermal resistance of the adhesive will be decreased by decrease of glass transition temperature of the adhesive. Epoxy resin modified with siloxane-imide was synthesized to improve thermal resistance and peel strength of the adhesive, after that the properties of modified epoxy resin were compared with the commercial epoxy resin. When 5% XNBR was added to 30% modified epoxy resin, this adhesive showed 0.42 N/mm of peel strength and 155℃ of glass transition temperature. These properties are enough compared to the required properties by the industry, i.e., 0.3 N/mm and 150℃, respectively. Weight loss of the modified epoxy resin by the treatment of nitric acid and 0.1N NaOH was reduced, but weight gain by the humid condition was increased by the presence of benzene ring and imide ring. 30% modified epoxy resin blended with 5% XNBR showed 220% improvement in tensile strength and elongation compared to the case of common epoxy resin. This is due to the flexibility of the siloxane in the modified epoxy resin.

Effect of materials structure and composition on properties of siloxane-containing hydrogels

Younghwan Kwon,Minhyeon Song,Yong Gu Hwang,Seung Hyun Chang,Won Ji Hong 한국물리학회 2008 Current Applied Physics Vol.8 No.3,4

Properties of siloxane-containing hydrogels were investigated with formulations of siloxane-containing monomer (TRIS) and/or poly(dimethylsiloxane) macromers with hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and N,N-dimethyl acrylamide (DMA). Phase separation behavior of siloxane-containing hydrogels was found to be affected mainly by compositions of siloxanebased hydrophobic/hydrophilic monomers. Properties of siloxane-containing hydrogels were investigated with formulations of siloxane-containing monomer (TRIS) and/or poly(dimethylsiloxane) macromers with hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and N,N-dimethyl acrylamide (DMA). Phase separation behavior of siloxane-containing hydrogels was found to be affected mainly by compositions of siloxanebased hydrophobic/hydrophilic monomers.

수산화철-분말활성탄 혼합 흡착제의 유입 혼합가스 조건에 따른 황화수소와 실록산 제거 특성

이성우 ( Seongwoo Lee ),김대근 ( Daekeun Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회지 Vol.36 No.2

The purpose of this study was to investigate the effect of gas composition with an iron hydroxide-activated carbon powder composite for the removal of hydrogen sulfide and siloxane (D4) in a fixed bed reactor. As a result of the breakthrough test that controlled the space velocity, initial concentration, relative humidity, oxygen, and gas mixture of methane/carbon dioxide, the adsorption capacity of hydrogen sulfide for the iron hydroxide-activated carbon powder composite was improved up to five times by 60% of the relative humidity. In addition, the space velocity and initial concentration were found to be important factors. The adsorption capacity of siloxane increased by 0.168 g siloxane/g adsorbent with increasing space velocity. In the case of simultaneous removal of hydrogen sulfide and siloxane, the adsorption capacity of hydrogen sulfide was negligible compared with that of siloxane, and the adsorption capacity of the siloxane was decreased by the hydrogen sulfide.

Anti-pilling of Cashmere Knitted Fabric Based on Siloxane-Modified Chitosan

Wanyun Tian,Luyi Chen,Xue Zhang,Yarong Wu 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

In this study, chitosan was modified by two kinds of different siloxanes, γ-glycidoxypropyl-trimethoxysilane (GPTMS) and γ-glycidoxypropyl-dimethoxy- methylsilane (GPDMS), respectively, then applied for anti-pilling of cashmere knitted fabrics. The structure of the modified chitosan, the apparent morphology and the mechanical properties of the modified film were analyzed by FTIR, SEM and DMA, respectively. The hydrophilicity and swelling properties of the modified film were compared. The results showed that epoxy groups of siloxane reacted with amino groups of chitosan, and the –OR (R represents alkyl) groups of siloxane hydrolyzed and polycondensation conducted during the film-forming process. After modification, the mechanical properties of the film were more flexible, the hydrophilicity and swelling of the film was decreased. Cashmere knitted fabric was treated with the modified chitosan and glutathione was chosen as the model compound to explore the reaction between modified chitosan and cashmere fibers. The apparent morphology and elements distribution of the fibers were observed by SEM and EDS, respectively. The directional friction effect of the fibers was tested by fiber friction coefficient tester. The pilling grade, handle, whiteness and launderability of fabric were investigated. The results showed that the epoxy groups remaining in siloxane were reacted with the amino groups of cashmere fiber, which enhance the binding of the fiber and siloxane-modified chitosan, the siloxane-modified chitosan film formed on fibers in situ. The directional friction effect of the fiber significantly reduced, the tendency of fuzzes to the surface of the fabric was weakened and the probability of tangling of exposed fuzzings was reduced, the pilling grade of the fabric treated by modified chitosan reached level 4 and the fabrics had good launderability, the soft and smooth handle was still preserved. There was no obvious color difference of cashmere fabrics treated with siloxane-modified chitosan.

Siloxane-Encapsulated Upconversion Nanoparticle Hybrid Composite with Highly Stable Photoluminescence against Heat and Moisture

Kuk, Su Keun,Jang, Junho,Han, Hyeuk Jin,Lee, Eunsang,Oh, Hyeongyeol,Kim, Hwea Yoon,Jang, Jinhyeong,Lee, Kang Taek,Lee, Hohjai,Jung, Yeon Sik,Park, Chan Beum,Bae, Byeong-Soo American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.17

<P>Herein, we report a siloxane-encapsulated upconversion nanoparticle hybrid composite (SE-UCNP), which exhibits excellent photoluminescence (PL) stability for over 40 days even at an elevated temperature, in high humidity, and in harsh chemicals. The SE-UCNP is synthesized through UV-induced free-radical polymerization of a sol-gel-derived UCNP-containing oligosiloxane resin (UCNP-oligosiloxane). The siloxane matrix with a random network structure by Si-O-Si bonds successfully encapsulates the UCNPs with chemical linkages between the siloxane matrix and organic ligands on UCNPs. This encapsulation results in surface passivation retaining the intrinsic fluorescent properties of UCNPs under severe conditions (e.g., 85 °C/85% relative humidity) and a wide range of pH (from 1 to 14). As an application example, we fabricate a two-color binary microbarcode based on SE-UCNP via a low-cost transfer printing process. Under near-infrared irradiation, the binary sequences in our barcode are readable enough to identify objects using a mobile phone camera. The hybridization of UCNPs with a siloxane matrix provides the capacity for highly stable UCNP-based applications in real environments.</P> [FIG OMISSION]</BR>

실리콘 폴리머의 내전압 및 절연특성에 관한 연구

지원영 한국전기전자재료학회 2001 전기전자재료학회논문지 Vol.14 No.11

The fundamental study on HTV silicone for insulation material has been performed. In order to estimate the chemical behavior of siloxane under high voltage, H-NMR, GPC and vinyl contents measurement were used. As an experimental results, after high voltage stress, the molecular weight of siloxane are increased, the vinyl contents of siloxane are decreased. The dielectric strength of vinyl group containing siloxane was lower than only methyl containing siloxane.