• Title/Summary/Keyword: Modified microparticle

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Retention Performance of Nanocoated GCC with Positive Charge (양이온성으로 표면 개질된 nanocoated GCC의 보류 성능)

  • Lee, Jegon;Sim, Kyujeong;Lee, Hak Lae;Youn, Hye Jung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.5
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    • pp.14-22
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    • 2013
  • In this study, we investigated retention characteristics of nanocoated GCC that was positively modified by Layer-by-Layer (LbL) multilayering process. Three layers were formed onto GCC particles with poly-DADMAC/PSS/poly-DADMAC (PD3) and C-starch/A-PAM/C-starch (CS3) systems, respectively. Untreated GCC, PD3 GCC (strongly positive charge) and CS3 GCC (weekly positive charge) were retained on pulp fibers under single retention system or microparticle retention system conditions. In single retention system, PD3 particles were not affected by cationic retention aid due to their strong positive charge, whereas CS3 particles reacted with cationic retention aid due to anionic sites on the surface of the weekly positive particles. In a microparticle retention system, positively modified GCC (PD3 and CS3) showed higher retention level than untreated GCC at the same dosage of retention aid. The cationic surface of GCC particles were more reacted with bentonite so the deposition onto pulp fibers was improved. In addition, the retention level of nanocoated GCC was increased with maintaining good formation.

Improve H2S Gas Sensing Characteristics through SnO2 Microparticle Surface Modification and Ti Nanoparticle Decoration using Tip Sonication (Tip sonication을 이용한 SnO2 마이크로 입자 표면 개질 및 Ti 나노 입자 장식을 통한 H2S 가스 감지 특성 향상)

  • Ji Yeon Shin;Chan Gyu Kim;Ji Myeong Park;Hong Nhung Le;Jeong Yun Hwang;Myung Sik Choi
    • Journal of Sensor Science and Technology
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    • v.33 no.2
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    • pp.105-111
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    • 2024
  • In this study, the H2S gas sensing characteristics were evaluated using surface-modified SnO2 microparticles by tip sonication. The surface-modified SnO2 microparticles were synthesized using the following sequential process. First, bare SnO2 microparticles were synthesized via a hydrothermal method. Then, the surfaces of bare SnO2 microparticles were modified with Ti nanoparticles during tip sonication. The sensing characteristics of SnO2 microparticles modified with Ti were systematically investigated in the range of 100-300℃, compared with the bare SnO2 microparticles. In this study, we discuss in detail the improved H2S sensing characteristics of SnO2 microparticles via Ti nanoparticle modification.