TY - JOUR
T1 - Properties of complexes and particles of gelatin with ionic surfactants
AU - Vinetsky, Y.
AU - Magdassi, S.
PY - 1998/5
Y1 - 1998/5
N2 - The properties of soluble gelatin-ionic surfactant complexes and insoluble particles were evaluated. It was found that colloidal particles of gelatin A - cationic surfactant (dodecyltrimethyl-ammonium bromide, DTAB, and cetyltrimethylammonium bromide, CTAB) were formed. Binding isotherms showed that these particles are obtained above the CMC of each surfactant, while cooperative binding takes place. Surface tension measurements conducted for both gelatin/DTAB and gelatin/anionic surfactant, SDS (sodium dodecyl sulfate) showed a break in the curve describing surface tension vs number of bound surfactant molecules, (ν) at concentrations below the CMC of each surfactant alone. This break, which is attributed to CMC 1, is observed at the same number of bound surfactant molecules ν ~ 2 for both gelatin/surfactant couples. Contact angle measurements showed that the maximal hydrophobicity of the gelatin-surfactant particles is obtained at the same concentration range in which the precipitation occurs. It was also found that the hydrophobicity of gelatin-SDS particles, is higher than that of the gelatin-cationic surfactants, due to a different composition of the resulting particles. The zeta potential of the particles indicated charge neutralization and even charge reversal for gelatin-CTAB at high surfactant concentration.
AB - The properties of soluble gelatin-ionic surfactant complexes and insoluble particles were evaluated. It was found that colloidal particles of gelatin A - cationic surfactant (dodecyltrimethyl-ammonium bromide, DTAB, and cetyltrimethylammonium bromide, CTAB) were formed. Binding isotherms showed that these particles are obtained above the CMC of each surfactant, while cooperative binding takes place. Surface tension measurements conducted for both gelatin/DTAB and gelatin/anionic surfactant, SDS (sodium dodecyl sulfate) showed a break in the curve describing surface tension vs number of bound surfactant molecules, (ν) at concentrations below the CMC of each surfactant alone. This break, which is attributed to CMC 1, is observed at the same number of bound surfactant molecules ν ~ 2 for both gelatin/surfactant couples. Contact angle measurements showed that the maximal hydrophobicity of the gelatin-surfactant particles is obtained at the same concentration range in which the precipitation occurs. It was also found that the hydrophobicity of gelatin-SDS particles, is higher than that of the gelatin-cationic surfactants, due to a different composition of the resulting particles. The zeta potential of the particles indicated charge neutralization and even charge reversal for gelatin-CTAB at high surfactant concentration.
KW - Binding
KW - Cetyltrimethylammonium bromide
KW - Dodecyltrimethyl-ammonium bromide
KW - Gelatin
KW - Hydrophobicity
KW - Sodium dodecyl sulfate
KW - Surface tension
KW - Surfactant
KW - Zeta potential
UR - http://www.scopus.com/inward/record.url?scp=0031852996&partnerID=8YFLogxK
U2 - 10.1007/s003960050258
DO - 10.1007/s003960050258
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AN - SCOPUS:0031852996
SN - 0303-402X
VL - 276
SP - 395
EP - 401
JO - Colloid and Polymer Science
JF - Colloid and Polymer Science
IS - 5
ER -