• Title/Summary/Keyword: exothermic behavior

검색결과 71건 처리시간 0.015초

Adsorption Thermodynamics of Polyamidoamide Epichlorohydrin Polymer in an Aqueous Fibrous Suspension (섬유 현탁액내 PAE 고분자 흡착의 열역학적 고찰)

  • Sung-Hoon Yoon;Kwang-Suk Joo;Tae-Won Lee;Kun-Han Kim;Byung-Bin Park
    • Journal of the Korean Chemical Society
    • /
    • 제47권3호
    • /
    • pp.220-228
    • /
    • 2003
  • This study was to examine the thermodynamic features of polyelecrolytic adsorption of polyamidoamine-epichlorohydrin(PAE) in a papermaking wet-end. The PAE adsorption experiments were conducted in a stirred jar containing an aqueous fibrous suspension and evaluated in terms of Langmuir and Freundlich parameters. The electrokinetic property of a stock was examined by measuring the zeta potential of each colloidal suspension. The polyelectrolytic PCD titration was employed to determine the adsorbed amounts of PAE polymer. The zeta potential of a stock, being varied significantly depending upon the addition of PAE polymer, showed initially a sharp increase and later an exponential decay as a function of time . The PAE adsorption exhibited a pseudo-Langmuir adsorption behavior at$20^{\circ}C$ , whereas its Freundlich power(v) increased in a proportional way at an elevated temperature. The train numbers calculated on the basis of adsorption thermodynamics were 7 to 8. The length of the extended loop of PAE was calculated as 215 nm at $20^{\circ}C$ and increased at a rate of 9% at every $10^{\circ}C$ rise in temperature. The PAE adsorption was proven to be an exothermic physisorption with the estimated adsorption enthalpy of -27 to -29 kJ/mol.