• Title/Summary/Keyword: chemical pre-treatment

Search Result 368, Processing Time 0.028 seconds

Effect of Pre-Treatment by Ozone on Chemical Surface Modification of Activated Carbon Fiber (오존에 의한 전처리가 활성탄소섬유 화학적 표면개질에 미치는 영향)

  • Jang, Jung Hee;Han, Gi Bo;Kim, Ho
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.35 no.6
    • /
    • pp.415-421
    • /
    • 2013
  • To increase specific surface property of activated carbon fiber(ACF), chemical activation(CA) using alkali metals and surface treatment(ST) using oxidant was widely used. The CA and ST process developed micro-pore on the surface of ACF by chemical reaction of the alkali metals and oxidative of oxidant, respectively. To improve the efficiency of CA process for developing micro-pores on the surface of ACF, the ST process was adopted as an pre-treatment method. After treatment of ST process, ACF properties was investigated depending on the ST pre-treatment process. FT-IR, TG and elemental analysis of the ACF are carried out, and an adsorption property of ACF was also evaluated using toluene(which in typical volatile organic matter). Once the single CA process is used, the surface area and adsorption capacity of ACF were increased from 1,483 to 1,988 $m^2/g$ and from 0.22 to 0.27 $g_{-Tol.}/g_{-ACF}$, respectively. On the other hands, once the ST and CA processes are used successively, the surface area and adsorption capacity of ACF are greatly increase(where the surface area is 2,743 $m^2/g$ and the adsorption capacity is 0.37 $g_{-Tol.}/g_{-ACF}$). It indicates that the combined process of ST and CA can improve the surface process properties of ACF.

Potassium loading effects for nano-porous ACF pre-fronted with phosphoric acid

  • Oh, Won-Chun;Lim, Chang-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.16 no.3
    • /
    • pp.106-111
    • /
    • 2006
  • The objective of this paper is to compare the surface features of two kinds of nano-porous activated carbon fiber (NPACF) treated with potassium and the variation of their properties by phosphoric acid pre-treatment. X-ray diffraction (XRD) patterns indicate that NPACF containing potassium species show better performance for potassium and potassium salts by pre-treatment with phosphoric acid. In order to present the causes of the differences in surface properties and specific surface area after the samples were treated with phosphoric acid, pore structure and surface morphology are investigated by adsorption analysis and SEM. For the chemical composition microanalysis for potassium loading of the NPACF pre-treated with phosphoric acid, samples were analyzed by EDX. Finally, the type and quality of oxygen groups are determined from the method proposed by Boehm.

Effect of Ion-beam Pre-treatment on the Interfacial Adhesion of Sputter-deposited Cu film on FR-4 Substrate (이온빔 전처리가 스퍼터 증착된 Cu 박막과 FR-4 기판 사이의 계면접착력에 미치는 영향)

  • Min, Kyoung-Jin;Park, Sung-Cheol;Lee, Ki-Wook;Kim, Jae-Dong;Kim, Do-Geun;Lee, Gun-Hwan;Park, Young-Bae
    • Korean Journal of Metals and Materials
    • /
    • v.47 no.1
    • /
    • pp.26-31
    • /
    • 2009
  • The effects of $Ar/O_2$ ion-beam pre-treatment conditions on the interfacial adhesion energy of sputterdeposited Cu thin film to FR-4 substrate were systematically investigated in order to understand the interfacial bonding mechanism for practical application to advanced chip-in-substrate package systems. Measured peel strength increases from $45.8{\pm}5.7g/mm$ to $61.3{\pm}2.4g/mm$ by $Ar/O_2$ ion-beam pre-treatment with anode voltage of 64 V. Interfacial bonding mechanism between sputter-deposited Cu film and FR-4 substrate seems to be dominated by chemical bonding effect rather than mechanical interlocking effect. It is found that chemical bonding intensity between carbon and oxygen at FR-4 surface increases due to $Ar/O_2$ ion-beam pretreatment, which seems to be related to the strong adhesion energy between sputter-deposited Cu film and FR-4 substrate.

Effects of Pre-treatments on the Oil Palm EFB Fibers (오일팜 EFB 섬유의 전처리 영향 평가)

  • Kim, Dong-Seop;Sung, Yong Joo;Kim, Chul-Hwan;Kim, Se-Bin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.44 no.6
    • /
    • pp.36-42
    • /
    • 2012
  • The empty fruit bunch fibers(EFB) of oil palm were examined for optimal utilization of the EFB fibers. The EFB fibers were obtained by shredding EFB, followe by removal of fines. The surface properties of the fibers were modified with various pre-treatments, such as hot water extraction, the soaking treatments with NaOH, $ClO_2$ and n-hexane. The changes in the fiber surface were examined with FT-IR method, which showed the changes in chemical compositions such as pectin, lignin, and etc. according to the pre-treatment methods. And the z-directional tensile testing of the fiber mold made of the treated EFB fibers showed the changes in the bonding strength by the pre-treatments. The fiber mold made of EFB fibers treated with $ClO_2$ showed the greater increase in the tensile energy absorption although the NaOH treatment resulted in the severer impact on the EFB fibers.

Strength property improvement of OCC-based paper by chemical and mechanical treatments (2) (골판지 고지의 물리화학적 처리에 의한 강도향상 (제2보))

  • Lee, Jong-Hoon;Seo, Yung B.;Jeon, Yang;Lee, Hak-Lae;Shin, Jong-Ho
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2000.04a
    • /
    • pp.69-69
    • /
    • 2000
  • In the previous experiment, it was found that OCC pre-treatment with Hobat mixer at 20-25% consistency for 3 hrs or more followed by the application of the equal refining time, caused the increase of tensile strength, burst strength, compressive strength and tear resistance, compared to the no pre-treated. Four completely different fibers, which were Hw-BKP, Sw-BKP, White ledger, and OCC were selected for this experiment to investigate the effect of mechanical pre-treatment process on different fibers. From the experiment, it was found that the mechanical pre-treatment did not decrease fiber length at all, but decreased freeness, compared to the no pre-treated, when the same refining time was applied WRVs of the pre-treated fibers were higher than the no pre-treated at the same freeness level. It was speculated that the mechanical pre-treatment induced only hydrophilic nature of fibers without damaging fiber length by delaminating fiber walls. The fiber surface area and the physical strength differences of handsheets will be discussed in the next publication.

  • PDF

APPLICATION OF TUBULAR MEMBRANE FILTRATION TO LNDUSTRIAL WASTE WATER TRATMENT (산업폐수에 관형막 분리응용)

  • 지은상
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 1991.10a
    • /
    • pp.58-63
    • /
    • 1991
  • Membrane technology has been effectively used for many years in certain segments of industrial water treatment. Recent advances in combining sophisticated chemical pre-treatment technology with cross-flow membrane filtration technology have successfully demonstrated that highly efficient, low-cost methods for treating a large of industral streams are available.

  • PDF

Adhesion Enhancement of Polyurethane Foam Using Atmospheric Plasma (II) (대기압 플라즈마를 이용한 폴리우레탄 소재의 접착력 향상 (II))

  • Sim, Dong Hyun;Seul, Soo Duk;Oh, Sang Taek
    • Journal of Adhesion and Interface
    • /
    • v.8 no.3
    • /
    • pp.1-8
    • /
    • 2007
  • An atmospheric plasma pre-treatment method was applied to polyurethane foam to improve its contact angle and adhesion. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen, argon, oxygen, air), rate of gas flow (30~150 mL/min), and reaction time (0~30 sec) were examined in a plate plasma reactor. Also, the effects were compared to those of a conventional vacuum plasma pre-treatment system. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of polyurethane foam, the greatest adhesion strength was achieved at a flow rate of 100 mL/min and at a reaction time of 10s for N2 gas. Consequently, the atmospheric plasma treatment reduced the contact angle of the polyurethane foam and also resulted in the improvement of the peel strength.

  • PDF

Study of cotton linter pre-treatment process for producing high quality regenerated fibers for fabrics (방직용 고품질 재생섬유 제조를 위한 면린터 전처리공정에 관한 연구)

  • Park, Hee Jeong;Han, Jung Su;Son, Ha Neul;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.45 no.3
    • /
    • pp.27-35
    • /
    • 2013
  • Cotton linter pre-treatment methods using electron beam and sulfuric acid were investigated to prepare high quality regenerated fibers for fabrics. So far, NaOH was used to reduce the degree of polymerization (DP) of the cotton linter for ease of dissolving by cellulose solvent. Two pre-treatment methods were developed to reduce the consumption of the chemicals (NaOH) and to control the DP of cellulose more precisely. Changes in ${\alpha}$-cellulose contents and brightness by the pre-treatments were also important concerns. Both electron beam irradiation and sulfuric acid were shown to be effective on controlling the DP of cellulose and to reduce the chemical consumption, but reduced ${\alpha}$-cellulose contents as well in this study. Sulfuric acid pre-treatment, which needed additional washing process after the pre-treatment when comparing to the electron beam irradiation method, gave the highest brightness and the highest reduction of ${\alpha}$-cellulose content.

Strength Property Improvement of OCC-based Paper by Chemical and Mechanical Treatments (III) - Handsheet physical properties - (골판지 고지의 물리화학적 처리에 의한 강도향상(제3보) - 수초지의 물리적 특성변화 -)

  • Lee, Jong-Hoon;Seo, Yung B.;Jeon, Yang;Lee, Hak-Lae;Shin, Jong-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.32 no.2
    • /
    • pp.8-15
    • /
    • 2000
  • This study is a continuation of the previous experimental analysis and is mostly focused on handsheet strength properties. Four completely different fibers, which were Hw-BKP, SW-BKP, White ledger, and OCC, were selected to investigate the effect of mechanical pre-treatment by Hobart mixer on handsheet strehgth properties. After equal time mechanical pre-treatment, the fibers were refined with laboratory valley beater for 10, 20 and 30 minutes, and handsheets were prepared from the fibers for physical strength comparison. Handsheets from SW-BKP and OCC showed 5-30% increase of breaking length, burst index, tear index, and compression index while handsheets from HW-BKP and White ledger no increase except tear index. In Hobart mixer pre-treatment, HW-BKP and White ledger fibers were easily attached to the wall of the mixer bowl and mechanical action was not effectively applied. The fiber length of Hw-BKP and White ledger were 0.837 mm and 1.591 mm, respectively, while SW-BKP and OCC were 2.744 mm and 2.033 mm, respectively, in weight weighted length. The effective mechanical pre-treatment seems to be related to the fiber length. Tear indexes of the pre-treated furnish were much higher than no pre-treatment at the same breaking length level.

  • PDF

Strength property improvement of OCC-based paper by chemical and mechanical treatments (3 - handsheet physical properties) (골판지 고지의 물리화학적 처리에 의한 강도향상 (제3보 - 수초지의 물리적특성변화))

  • Lee, Jong-Hoon;Seo, Yung B.;Jeon, Yang;Lee, Hak-Lae;Shin, Jong-Ho
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2000.04a
    • /
    • pp.70-70
    • /
    • 2000
  • This study is a continuation of the previous experimental analysis and is mostly focused on handsheet strength properties. Four completely different fibers, which were Hw-BKP, Sw-BKP, white ledger, and OCC, were selected to investigate the effect of mechanical pre-treatment by Hobart mixer on handsheet strength properties. After equal time mechanical pre-treatment, the fibers were refined with laboratory valley beater for 10, 20 and 30 minutes, and handsheets were prepared from the fibers for physical strength comparison. Handsheets from SW-BKP and OCC showed 5-30% increase of breaking length, burst index, tear index, and compression index while handsheets from HW-BKP and white ledger no Increase except tear index. In Hobart mixer pre-treatment, HW-BKP and white ledger fibers were easily attached to the wall of the mixer bowl and mechanical action was not effectively applied. The fiber length of Hw-BKP and white ledger were 0.837mm and 1.591 mm, respectively, while SW-BKP and OCC were 2.744 mn and 2.033 mm, respectively, in weight weighted length. The effective mechanical pre-treatment seems to be related to the fiber length. Tear indexes of the pre-treated furnish were much higher than no pre-treatment at the same breaking length level.

  • PDF