기액 계면에서 2,4,-Hexadecadienoic Acid의 단분자 막 거동에 대한 pH와 염의 영향

김승렬; 이규종; 김길호; 김종득

Polymer(Korea), Vol.16, No.3, 363-371, May, 1992

Export Citation

기액 계면에서 2,4,-Hexadecadienoic Acid의 단분자 막 거동에 대한 pH와 염의 영향

The pH and Salt Effect on the Monolayer Behaviors of 2,4-Hexadecadienoic Acid at the Air/Water Interface

김승렬, 이규종, 김길호, 김종득

초록

기액 계면상에서 2,4-Hexadecadienoic acid(HDDA) 단분자막의 거동에 대한 pH와 염의 영향을 살펴 보았다. HDDA는 이중결합을 지니므로 π-A 등온선(surface pressure-surface area isotherm)에서 보여지는 계면거동이 palmitic acid와는 다르다. HDDA단분자막은 diene기의 영향으로 팽창상만을 나타내며 큰 분자당 면적을 갖는다. 단분자막의 pH에 따른 π-A 등온선, 반복 효과, 일정 표면압하의 면적변화 등의 실험으로부터 막손실의 주 원인이 막붕괴보다는 액상으로의 용해에 기인됨 을 알 수 있었다. 염을 사용한 실험에 서 Al³⁺은 안정한 표면구조를 형성함에 따라 단분자막의 안정성을 증가시켰다. π-A 등온선에서 보이는 상전이는 diene기가 수면상에서 일어서 소수기로 작용하기 때문이다. 이에 비하여 Ba²⁺는 안정성에 영향이 없는 반면, Cd²⁺는 액상으로의 용해를 가속화시켰다. 따라서 보상효과를 갖는 용해와 막붕괴에 의한 단분자막의 손실에는 최적 pH가 존재하며, 적절한 염을 사용하여 안정한 단분자막을 형성시킬 수 있었다.

The surface behavior of 2,4-hexadecadienoic acid (HDDA) on the air/water interface has been investigated on the effects of pH and salts. Since HDDA has a conjugated double bond, its π-A isotherm differs from that of palmitic acid. The HDDA monolayer exibited only the expanded phase and large limiting area because of the orientation caused by the diene group. The π-A isotherms, repetition effects and area change at constant π with pH indicated that the main factor of film loss was the dissolution rather than the film collapse of HDDA. Considering salt effects, Al³⁺ ion improved the monlayer stability by forming a stable surface structure of the film. Also the phase transition of film was observed. Perhaps it is because that diene group works as hydrophobic group by lifting a conjugated double bond from the water surface. However, Ba²⁺ did not show any effects, and Cd²⁺ accelerated the dissolution of monolayer into the subphase. In summary, the film loss by the dissolution and collapse could be reduced under the conditions of optimum pH, and the stability of monolayer was increased by the use of good salts.

[References]

Kowel ST, Selfridge R, Eldering C, Matloff N, Thin Solid Films, 152, 377 (1987)
Sugi M, Thin Solid Films, 152, 305 (1987)
Ringsdorf H, Schupp H, J. Macromol. Sci.-Chem., A15, 1015 (1981)
Laschewsky A, Ringsdorf H, Macromolecules, 21, 1936 (1988)
Roberts G, "Langmuir-Blodgett Films," pp. 73-76, Plenum Press, New York (1990)
Dorn K, Klingbiel RT, Specht DP, Tyminski PN, Ringsdorf H, O'Brien DP, J. Am. Chem. Soc., 106, 1627 (1984)
Mingins J, Owens NF, Thin Solid Films, 152, 9 (1987)
Muller A, Proc. Roy. Soc., 114, 542 (1927)
Wiedmann TS, Fordan KR, Langmuir, 7, 318 (1991)
Davies JT, Rideal EK, "Interfacial Phenomena," p. 265, 2nd Ed., Academic Press, New York (1963)
Xu S, Miyano K, Abraham BM, J. Colloid Interface Sci., 89, 581 (1982)
Gaines GL, "Insoluble Monolayers at Liquid-Gas Interface," pp. 193-199, John Wiley & Sons, Inc., New York (1966)
Neuman RD, J. Colloid Interface Sci., 53, 161 (1975)

[Referenced By]

[1] Kowel ST, Selfridge R, Eldering C, Matloff N, Thin Solid Films, 152, 377 (1987)

[2] Sugi M, Thin Solid Films, 152, 305 (1987)

[3] Ringsdorf H, Schupp H, J. Macromol. Sci.-Chem., A15, 1015 (1981)

[4] Laschewsky A, Ringsdorf H, Macromolecules, 21, 1936 (1988)

[5] Roberts G, "Langmuir-Blodgett Films," pp. 73-76, Plenum Press, New York (1990)

[6] Dorn K, Klingbiel RT, Specht DP, Tyminski PN, Ringsdorf H, O'Brien DP, J. Am. Chem. Soc., 106, 1627 (1984)

[7] Mingins J, Owens NF, Thin Solid Films, 152, 9 (1987)

[8] Muller A, Proc. Roy. Soc., 114, 542 (1927)

[9] Wiedmann TS, Fordan KR, Langmuir, 7, 318 (1991)

[10] Davies JT, Rideal EK, "Interfacial Phenomena," p. 265, 2nd Ed., Academic Press, New York (1963)

[11] Xu S, Miyano K, Abraham BM, J. Colloid Interface Sci., 89, 581 (1982)

[12] Gaines GL, "Insoluble Monolayers at Liquid-Gas Interface," pp. 193-199, John Wiley & Sons, Inc., New York (1966)

[13] Neuman RD, J. Colloid Interface Sci., 53, 161 (1975)