• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.154-154
• /
• 2008

Although the screen printing technology using photosensitive carbon nanotube (CNT) paste has many advantages such as low cost, simple process, uniform emission, and capability of mass production, the CNT paste needs to be improved further in CNT dispersion, printability, adhesion, electrical conductivity, population of CNT emitters, etc. Ball milling has been frequently employed to prepare the CNT paste as ball milling can mix its ingredients very well and easily cut the long, entangled CNTs. This study carried out a parametric approach to fabricating the CNT paste in terms of low-energy ball milling and a paste composition. Field emission properties of the CNT paste was characterized with CNT dispersion and electrical conductivity which were measured by a UV-Vis spectrophotometer and a 4-point probe method, respectively. Main variables in formulating the CNT paste include a length of milling time, and amounts of CNTs and conductive inorganic fillers. In particular, we varied not only the contents of conductive fillers but also used two different sizes of filler particles of ${\mu}m$ and nm ranges. Among many variations of conductive fillers, the best field emission characteristics occurred at the 5 wt% fillers with the mixing ratio of 3:1 for ${\mu}m$-and nm-sizes. The amount and size of fillers has a great effect on the morphology, processing stability, and field emission characteristics of CNT emitter dots. The addition a small amount of nm-size fillers considerably improved the field emission characteristics of the photosensitive CNT paste.

• 한국연초학회지
• /
• 제32권1호
• /
• pp.12-18
• /
• 2010

The parcel wrapper for cigarettes has been used as the package and media materials for protection and design of product brands. The design of parcel wrapper has been contributed to the delivery of brand image and motivated consumer to purchase the brand. Therefore, the properties of parcel wrapper have been paid attention to highlight the design image, and increasing opacity of media materials has been one of the effective ways to obtain clear design on the paper surface. This study was carried out to improve the opacity of parcel wrapper for cigarettes. The effects of pulp composition and inorganic fillers in the furnish on the optical and mechanical properties were investigated. The use of hardwood in the stock preparation gave the increased opacity of paper than that of softwood. The application of higher refractive indices of fillers was effective to improve opacity. Brightness, tensile strength and stiffness were affected by the retained filler amount on the paper. Increase of filler contents decrease the tensile strength and stiffness due to the lesser bonding ability of fibers.

• 한국재료학회지
• /
• 제22권11호
• /
• pp.604-608
• /
• 2012

Recently, inorganic-organic hybrid materials have attracted much attention not only for their excellent thermal conductivity but also for their flame retardant properties. In this study, the properties of organic-inorganic hybrid insulating materials using inorganic fillers and polyurethane foam with different foaming conditions have been investigated. The addition of 1.5 wt% water to polyurethane as foaming agent shows the best foaming properties. The pore size was decreased in the foaming body with increasing of the $CaCO_3$ addition. The apparent density and thermal conductivity were increased by increasing the $CaCO_3$ addition. With an increasing amount of $CaCO_3$ powder, the flame retardant property is improved, but the properties of thermal conductivity and apparent density tend to decrease. When the addition of fine particles of $CaCO_3$, the apparent density and thermal conductivity were increased and, also, with the addition of coarse particles over $45{\mu}m$ in size, the apparent density and thermal conductivity were increased as well. In this study, the adding of $CaCO_3$ with average particle size of $27{\mu}m$ led to the lowest thermal conductivity and apparent density. After evaluation with different inorganic fillers, $Mg(OH)_2$ showed the highest thermal conductivity; on the other hand, $CaCO_3$ showed the lowest thermal conductivity.

• 한국세라믹학회지
• /
• 제51권2호
• /
• pp.127-131
• /
• 2014

Precipitated calcium carbonate(PCC) inorganic fillers for plastic offera higher replacement ratio with improved mechanical properties than any other inorganic fillers. Due to its secure economic feasibility, its fields of application areexpanding. For optimized PCC grain size and polymer replacement ratio, it is good to maintain at least $0.035{\mu}m$ grains and keep double the grain size of distance between particles, depending on the molecular weight and volume replacement rate of the polymer. PCC has unique characteristics, ie, with smaller grain size, dispersibility decreases, and if grain size is not homogenous, polymer cracking occurs. The maximum replacement ratio of PCC is approximately 30%, but in the range of 10 - 15% it produces the highest mechanical strength. When mixed with a biodegradable plastic like starch, it also improves initial environmental degradability.

• 펄프종이기술
• /
• 제46권4호
• /
• pp.1-10
• /
• 2014

In papermaking industry, inorganic fillers are widely used for the purpose of improving opacity, brightness, printability, uniformity and dimensional stability. They are also useful for production costs and energy savings. In the past, inorganic fillers in papermaking industry only focused on micro-scale but recently, new trials on nano-powdered technology are applying. Even nano-powdered fillers are rapidly utilized for improving the optical and surface properties in coating and surface sizing, there still have some problems in wet-end process due to poor dispersibility and retention. In this study, nano-particled calcium carbonate was produced by milling the PCC and its applicability between micro sized and nano sized calcium carbonated was compared in wet-end process, and finally the sheet properties were evaluated. Nano-PCC was not retained in sheet structure without applying retention system, but with retention system nano-powdered PCC was absorbed on fiber surface with expanding the fiber networks. The application of PAM-bentonite system has resulted in high ash retention and bulky structure for copier paper, and good optical properties in brightness and opacity. However, it required to solve the weakness of low tensile property due to interruption of hydrogen bonding by nano fillers.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2002년도 봄 학술발표회 논문집
• /
• pp.321-324
• /
• 2002

Recently, organic-inorganic nanocomposites have attracted great interest from researchers since they frequently exhibit unexpected hybrid properties synergistically derived from two components[1]. The addition of highly dispersed inorganic nano-sized fillers permits improvement of certain properties of polymers as compared with conventional particulate composites; increase of modulus and strength, improved barrier properties, increase in solvent and heat resistance, and good optical properties[2]. (omitted)

• 한국수소및신에너지학회논문집
• /
• 제32권6호
• /
• pp.524-533
• /
• 2021

In this study, a series of anion conductive organic/inorganic composite membranes with excellent ionic conductivity and chemical stability were prepared by introducing graphene oxide (GO) inorganic nanofiller into the quaternized poly(phenylen oxide (Q-PPO) polymer matrix. The fabricated organic/inorganic composite membranes showed higher ionic conductivity than the pristine membrane. In particular, Q-PPO/GO 0.7 showed the highest ionic conductivity value of 143.2 mS/cm at 90℃, which was 1.56 times higher than the pristine membrane Q-PPO (91.5 mS/cm). In addition, the organic/inorganic composite membrane showed superior dimensional stability and alkaline stability compared to the pristine membrane, and the physicochemical stability was improved as the content of inorganic fillers increased. Therefore, we suggest that the as-prepared organic/inorganic composite membranes are very promising materials for anion exchange membrane applications with high conductivity and alkaline stability.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.814-817
• /
• 2003

The sintering behavior of $BaO-B_{2}O_{3}-ZnO$, which is Pb-free glass-ceramic system, was examined as functions of the composition and the amount and particle size of $Al_{2}O_{3}$ filler. Different kinds of modifiers were added and $Al_{2}O_{3}$ fillers with different particle sizes ($1.5{\mu}m$ and $4.5{\mu}m$) were added. The glass frit-filler composites were sintered in the temperature range $520{\sim}580^{\circ}C$. X-ray diffraction results revealed that some of the composites crystallized during sintering. Dielectric constant and thermal expansion coefficient the glass-ceramics were analyzed.

• 한국건설순환자원학회지
• /
• 제16권1호
• /
• pp.8-11
• /
• 2021

• 보존과학회지
• /
• 제27권4호
• /
• pp.431-440
• /
• 2011

석조문화재에 사용되는 에폭시 수지에 열팽창계수가 낮은 무기물을 첨가하여, 석재와 비슷한 수준으로의 열팽창계수 조절 및 무기물 첨가에 따른 기계적 변화를 연구하였다. 사용된 에폭시 주제는 hydrogenated bisphenol A (HBA), 경화제로는 상온에서 경화가 가능한 Isophoronediamine (IPDA), 점도 조절을 위한 반응성 희석제로는 difunctional polyglycidyl epoxide (DPE)를 선정하였으며 열팽창계수를 조절하기 위한 무기물 첨가제는 talc와 fused silica 를 사용하였다. 에폭시 수지와 희석제의 함량에 따라 점도를, 에폭시 수지와 무기물 첨가제의 부피비에 따른 열팽창계수를 측정하여 물리 화학적 물성 개선 가능성을 확인하였으며 인장강도, 전단강도 측정을 통하여 기계적 성능을 비교하였다. 연구결과 에폭시 수지에 첨가될 무기물 첨가제의 함량이 커질수록 열팽창 계수가 감소할 뿐만 아니라, 굴곡강도가 감소하고 전단 강도는 증가하는 특성이 나타났으며, fused silica를 사용한 에폭시 수지가 talc를 사용한 제품군에 비해 열팽창계수가 크게 감소하여 석재와 비슷한 수준으로 조절 가능함을 확인하였다.