Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
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Effect of Inorganic Salt Additives on Formation of Phase-Inversion Polyethersulfone Ultrafiltration Membrane

상변환 Polyethersulfone 한외여과막 제조시 무기염 첨가 효과

  • 김민정 (충북대학교 공과대학 화학공학부) ;
  • 이상덕 (충북대학교 공과대학 화학공학부) ;
  • 염경호 (충북대학교 공과대학 화학공학부)
  • Published : 2002.06.01
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Abstract

The effect of addition of inorganic salts in polyethersulfone (PES) polymer solution on the membrane formation and ultrafiltartion performance was studied through the thermodynamic and kinetic properties of casting solution. To control the thermodynamic and kinetic properties of casting solution, various inorganic salts $[CaC1_2, LiCl, LiClO_4, ZnC1_2 $and Mg(ClO_4)_2]$ were added in the PES/NMP solution. Variation of membrane morphology and performance of the resulting membranes with change of the salt type and content added in tasting solution were discussed using viscosity, coagulation value, light transmittance measurement, overall membrane porosity, ultrafiltration experiment and cross-sectional SEM image. For all kind of inorganic salts, according as increase of the salt content in casting solution, viscosity is increased, coagulation value becomes lower, top layer thickness below the skin surface is increased, bovine serum albumin(BSA) rejection decreased and pure water flux is increased except $CaC1_2$ and LiCl. In case of $CaC1_2$ and LiCl, it is found that when the salt content is increased, the formation of macrovoids is suppressed and the precipitation rate becomes slow while instantaneous demixing of precipitation type is maintained. However, in case of $LiClO_4$ and $Mg(ClO_4)_2,$ it is found that precipitation rate becomes faster.

Polyethesulfone(PES) 상변환 막 제조 시 캐스팅 용액에의 무기염 첨가가 막의 구조 및 성능에 미치는 효과를 캐스팅 용액의 열역학적.속도론적 특성치로서 연구하였다. PES/NMP 캐스팅 용액에 첨가시킨 무기염의 종류[CaCl_2, LiCl, LiCl_4, ZnCl_2 $및 Mg(ClO_4)_2]$와 양을 달리하여 제조된 막의 몰폴로지와 막성능(순수 투과량 및 용질 배제도)을 캐스팅용액의 점도와 coagulation vague, 제막시간에 따른 광투과도 변화, 총괄 다공도와 순수 투과량, bovine serum albumin(BSA) 용액의 한외여과 실험 및 막단면의 SEM 사진 결과로서 설명하였다. 이 결과 모든 종류의 무기염에 대해 첨가량이 증가할수록 캐스팅 용액의 점도는 증가하고, coagulation value는 낮아져 열역학적 불안정성이 증가하며, 막 단면 상층부(top layer below skin surface)의 an게가 증가하였으며, BSA 배제도는 감소하고 순수 투과량은 CaC1$_2$ 및 LiCl 무기염을 제외하고는 점차 증가하였다. CaC1$_2$ 및 LiCl 무기염을 첨가한 경우는 첨가량이 증가함에 따라 macrovoid의 형성이 억제되었으며, 순간분리의 침강형식은 유지하나 침강 속도가 점차 느려졌다. 반면 LiCl_4$ 및 Mg(ClO_4)_2$무기염을 첨가한 경우는 침강속도가 점차 빨라졌다.

Keywords

References

  1. UCLA Engineering Report No. 60-60 S. Loeb;S. Sourirajan
  2. ACS Symposium Series no.269 Production of microporous media H. Strathmann;D.R. Lloyd(ed.)
  3. Desalination v.16 The formation mechanism of asymmetric membranes H. Strathmann;K. Kock;P. Amar;R.W. Baker https://doi.org/10.1016/S0011-9164(00)82092-5
  4. J. Appl. Poym. Sci. v.23 The effect of low molecular weight additives on the properties of aromatic polyamide membranes M.A. Kraus;M. Nemas;M.A. Frommer https://doi.org/10.1002/app.1979.070230214
  5. J. Appl. Polym. Sci. v.35 Surface tension consideration for membrane casting systems K. Darcovich;O. Kutowy https://doi.org/10.1002/app.1988.070350705
  6. Ind. Eng. Chem. Res. v.26 Effect of polyvinylpyrrolidone additive on the performance of polyethersulfone ultrafiltration membranes L.Y. Lafreniere;F.D. F. Talbot;T. Matsuura;S. Sourirajan https://doi.org/10.1021/ie00071a035
  7. J. Memb. Sci. v.118 Effect of nonlolvent additives on the porosity and morphology of asymmetric TPX membranes J.Y. Lai;F.C. Lin;C.C. Wang;D.M. Wang https://doi.org/10.1016/0376-7388(96)00084-1
  8. J. Memb. Sci. v.138 Effect of PEG additive on membrane fromation by phase inversion J.H. Kim;K.H. Lee https://doi.org/10.1016/S0376-7388(97)00224-X
  9. Fundamentals of Fiber fromation;The Science of Fiber Spinning and Drawing A. Ziabicki
  10. J. memb. Sci. v.38 Effect of coagulation condition on structure and properties of membranes from aliphatic polyamides C.W. Yao;R.P. Burford;R.P.;A.G. Fane;C.J.D. Fell https://doi.org/10.1016/S0376-7388(00)80874-1
  11. Analytical Biochem. v.72 A rapid and sensitive method for the quantitaion of microgram quantities of protein utilizing the principle of protein dye binding M.M. Bradford https://doi.org/10.1016/0003-2697(76)90527-3
  12. Macromolecules v.27 Equilibrium thermodynamics of a quaternary membrane-forming system with two polymers. Ⅰ. Calculations R.M. Boom;Th. van den Boomgaard;C.A. Smolder https://doi.org/10.1021/ma00086a010
  13. Basic Principle of Membrane Technology M. Mulder
  14. J. Memb. Sci. v.34 Formation of membranes by means of immersion precipitation. Part Ⅱ. The mechanism on formation of membranes prepared from the system cellulose acetate-acetone-water A.J. Reuvers;C.A. Smolder https://doi.org/10.1016/S0376-7388(00)80021-6
  15. J. Appl. Polym. Sci. v.41 The four tiers of structure in integrally skinned phase inversion membranes and their relevance to the various separation regimes R.E. Kesting https://doi.org/10.1002/app.1990.070411120
  16. J. Colloid Interface Sci. v.147 Discussions on the formation mechanism of surface pores in reverse osmosis, ultrafiltration and microfiltration membranes prepared by phase inversion porcess Z. Zhenxin;T. Matsuura https://doi.org/10.1016/0021-9797(91)90162-2