• Macromolecular Research
• /
• v.9 no.2
• /
• pp.122-128
• /
• 2001

Monodisperse composite latex particles with size of ca. 300 nm, which consist ofn-butyl acrylate as a soft phase and methyl methacrylate as a hard phase with different morphology, were synthesized by seeded multi-stage emulsion polymerization. Three types of composite latex particles including random-, core/shell-, and gradient-type particles were obtained by using different monomer feeding methods during semi-batch emulsion polymerization. Effect of poly(butyl acrylate)-poly(methyl methacrylate) rubber particle morphology on the mechanical and rheological properties of rubber toughened poly(methyl methacrylate) was investigated. Among three different rubber particles, the gradient-type rubber particle showed better toughening effect than others. No significant variation of rheological property of poly(methyl methacrylate)/rubber blends was observed for the different rubber particle morphology.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.83-84
• /
• 2006

In aqueous phase, we directly prepared conducting and photoluminescent nano-structured particles by oxidation polymerization. Thiophene(PT) was initiated by $FeCl_{3}/H_{2}O_{2}$ (catalyst/oxidant) combination system. And, polydispersed core-shell poly(styrene/thiophene) and polyaniline(PANI)-coated multi core-shell polystyrene latex particles were successfully prepared by oxidative and radical polymerization. The resulting latex particles have fine improved luminescence and conductive efficiency and dispersion state due to the PT and PANI shell. Hyper functionalized nanoparticle would be expected to increase the processibility in various electrical and electro-optical fields.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.171-172
• /
• 2009

A Bonded Concrete Overlay is a layer of concrete bonded to the top of an existing pavement to rehabilitate it, to restore and increase its structural and functional capabilities and forming a monolithic structure with the existing pavement. This study focuses on the field application of BCO by very early strength latex modified concrete.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.995-997
• /
• 2003

In this study, we have investigated the positively charged polymer particles using emulsifier-free emulsion polymerization for applications in electrophoretic displays. The FT-IR, Zeta potential and SEM characteristics showed that by emulsifier-free polymerization, the positively charged polymer particles were manufactured. Using these particles, we can obtain well-dispersed white latex particles in dielectric suspending media.

• Journal of the Korean Chemical Society
• /
• v.45 no.2
• /
• pp.143-148
• /
• 2001

In this study, open tubular capillary columns for ion charomatography were developed to analyze trace amount of ions in samples. When small I,D. capillary column length is 1.0~5.0 m. The capillary columns were made using fused silica capillary(I.D:50㎛) and DMEOHA latex particles. The new conductivity cell and suppressor were also developed and made for capillary column ion chromatography. When several anions(fluoride, nitrite, nitale,chlorate,phosphte, sulfate) were analyzed using these capillary columns. reproducible and good chromatograms were obtained.

• 한국환경농학회:학술대회논문집
• /
• 2009.07a
• /
• pp.187-199
• /
• 2009

We present real.time, rapid detection of Mycoplasma pneumonia in phosphate buffered saline (PBS) inside a Y.channel polydimethylsiloxane (PDMS) microfluidic device by means of optical fiber monitoring of latex immunoagglutination. The latex immunoagglutination assay was performed with serially diluted Mycoplasma pneumonia solutions using highly carboxylated polystyrene particles of 390nm and 500nm diameter conjugated with monoclonal anti. Mycoplasma pneumonia . Proximity optical fibers were located around the viewing cell of the device, which were used to measure the increase in 45${\b{o}}$ forward light scattering of the immunoagglutinated particles. The detection limit was less than 50 $pgml^{-1}$ both for 390nm and 500nm microspheres with the detection time less than 90 seconds.

• The Journal of the Korean dental association
• /
• v.11 no.2
• /
• pp.123-129
• /
• 1973

The authors measured orthodontic force using the orthodontic materials of the Rocky Mountain Products Company. The results were as follows : ① Use latex of wide diameter in long distance, and when the latex of wide diameter activated by four or five times, we obtained a optimal force. ② The authors obtained canine retractions with sectional arch. Activation of sectional arch began at 1mm and had to do not activations of 3mm more. ③ The leveling started from .014 green round wire and finished to. 0.16" green Elgiloy round wire. Permit only a mild force in ideal arch form, in rectangular wire. ④ Fundamentaly, elastic thread obtained maximum force by activating as two times. ⑤ Coil spring obtained more heavy force from short distance than long distance.

• Journal of Industrial Technology
• /
• v.33 no.A
• /
• pp.101-107
• /
• 2013

The purpose of this study was to investigate bond strength between substrate and HES-LMS mortar, durability of HES-LMS mortar with latex content(0%, 5%, 10%). To measure the bond strength, the direct tensile test based on uniaxial tensile test was used, which was proposed by Kuhlman(1990). Also, Resistance for water permeability, water absorption and image analysis for air void system were conducted to estimating durability of HES-LMS mortar.

• Journal of Industrial Technology
• /
• v.26 no.A
• /
• pp.139-146
• /
• 2006

Many concrete bridge decks develop transverse cracking shortly after construction. These cracks accelerate corrosion of reinforcing steel and lead to concrete deterioration, damage to components beneath the deck, unsightly appearance. These cracks shorten the service life and increase maintenance costs of bridge structures. In this study, VES-LMC overlay, which provides the same benefits as a conventional overlay, is designed to cure very quickly. Although the materials for VES overlays are more expensive, the cost is more than offset by the savings on traffic control and work zone safety measures. Otherwise, reaction of hydration occurs very rapidly in beginning step(concrete placing). As a results, thermal cracking can be occur by thermal stress in accordance with hydration-heat The purpose of this study was to estimate diagnosis of crack occurrence of VES-LMC through field tests at early-age.

• Korean Journal of Veterinary Research
• /
• v.39 no.4
• /
• pp.806-810
• /
• 1999

A multiplex-polymerase chain reaction (PCR) assay was used to detect staphylococcal enterotoxin production by 12 strains of Staphylococcus aureus isolated from clinical specimens. To evaluate the efficacy and/or sensitivity of this method, the results were compared to those obtained with the reversed passive latex agglutination kit (SET-RPLA, Denka Seiken, Japan). Of 10 strains positive by PCR were positive by RPLA but two strains, representing high sensitivity of the former method. Enterotoxin B was the most prevalent by the two methods. The kappa index between the two methods was 0.826, indicating a higher agreement and fully reliable for use. These results would suggest that sensitive, inexpensive, and relatively rapid multiplex-PCR technique may be an effective means for the detection of staphylococcal enterotoxin genes as an alternative to traditional methods such as kits or immunological methods, which depend upon the amount of enterotoxin produced.