To understand the mechanism of adsorption of cationic polymer at the hair-water interface in the presence of anionic surfactant

1. : To determine the interfacial behavior of anionic surfactant (SLES) in the
presence of cationic polymer, we have studied the interfacial adsorption of cationic
polymer (polyquaternium 10, PQ10) at the hair-water interface in the presence of
sodium laureth sulphate. The interaction of the polymer with the anionic surfactant
was determined from the measurement of surface tension and foam volume. The
adsorption of the polymer on hair in presence of different surfactant concentrations
was followed from the analysis of signature peak of the polymer in the ATR-FTIR
spectra of hair. The surface tension of surfactant solution in the presence of polymer
was higher compared to the surfactant solution alone. The interaction of cationic
polymer with anionic surfactant leads to the decrease of free anionic surfactant in the
bulk medium. Therefore, the observed decrease in surface tension could be correlated
with the decreased availability of surfactant in bulk in the presence of cationic polymer.
Adsorption measurement with varied surfactant polymer ratio showed enhanced
adsorption on hair surface at 50:1 (w:w) anionic surfactant to polymer ratio in the bulk
medium.
Objective
To understand the mechanism of adsorption of cationic polymer at the hair-
water interface in the presence of anionic surfactant
Materials
SLES (Galaxy), PQ10 (Dow Chemicals) and Millique water
Methods
Surface tension. The surface tension of the samples were measured by drop
weight method. In drop weight method, the shape of a drop of liquid from a
capillary is dependent upon different forces including the surface tension of the
liquid. The drop weights are proportional to surface tension so that surface
tension of a liquid is given by :
where  is surface tension, N is number of drops,  is density, L is liquid and W
is water.
Zeta potential. The conductance and zeta potential of different surfactant
solution with and without polymer were measured using conductometer and
zeta sizer (Metrohm).
Adsorption of Polyquartenium-10 at hair-water interface in the presence of
Sodium Lauryl Ether Sulphate: Each hair tresses were divided into treated
and untreated portions. The hair was treated with samples (surfactant and
polymer in water), after 40rubs, the hair was rinsed with distilled water and then
dried. The deposition of polymer was quantified in ATR-FTIR by monitoring
the peak at 1045 cm-1, which is the signature peak for hydroxy ethyl cellulose
polymers. The variation of peak intensity gives the measure of deposition of
polymer on hair surface.
Results
Conclusions
Interfacial Behavior of Anionic Surfactant in the
Presence of Cationic Polymers
Kavitha Murugesan, Dhimoy Roy, Shoba R and Samares C Biswas*
ITC R & D Center, Karnataka, Bangalore -560058
ATR-FTIR Study of PQ10 Adsorption on Hair Surface
Bibliography
1. J. Livingston R. Morgan, J. Am. Chem. Soc., 1915, 37 (6), pp 1461–1467, DOI:
10.1021/ja02171a006
2. William D. Harkins, E. C. Humphery, J. Am. Chem. Soc., 1916, 38 (2), pp 228–236, DOI:
10.1021/ja02259a004
3. Lisa R. Huisinga, and Robert Y. Lochhead, Investigation of the Structure of
Polyelectrolyte-Based Complex Coacervates (pp 5)
• The ratio of surfactant to polymer has important role in the adsorption of
polymer on hair surface. The adsorption of polymer from anionic
surfactant solution depends on the balance between charge density and
hydrophobicity of the polymer surface.
• Overall charge of a surfactant-polymer system goes from positive to
negative with increasing surfactant concentration with zero being the CAC
region. Positive correlation between Surface Tension data and Zeta
Potential measurement
• From ATR-FTIR study one may note that the deposition of cationic
polymers is maximum at the neutralization region.
Abstract
WL
LWW
L
N
N





Surface Tension of SLES with & without PQ10
Adsorption of PQ10 on Hair
Zeta Potential-Neutralization of PQ10 with Surfactant
National Conference on Trends in Surface Science and Related Areas (TSSRA) Friday, November 19, 2010
CAC, Coacervation and CMC
of a surfactant-polymer system
is a function of the effective
charge density and
hydrophobicity of the polymer
and surfactant
The over all charge of
surfactant-polymer system
measured by Zeta Potential
shows a sigmoid pattern with
CAC being at zero. Positive
correlation for 0.01% PQ10
data can be seen
The ATR-FTIR spectra of
hair showed signature peak
of PQ10 @1045cm-1. The
adsorption of PQ10 is
maximum from 50:1
surfactant to polymer ratio.
From ATR-FTIR study one
may note that the deposition
of cationic polymers is
maximum at the
neutralization region.
Schematic Representation of Surfactant-Polymer complexation