News of Science
March 22, 2009

PHYSICAL CHEMISTRY;
Research conducted at A.H. Poghosyan and co-researchers has updated
our knowledge about physical chemistry

"We have performed a 50 ns of molecular dynamics study of
poly(diallyldimethylammonium chloride) (PDADMAC)/sodium dodecyl
sulfate (SDS)/decanol/water systems. The influence of the cationic
polyelectrolyte on the anionic SDS-based lamellar liquid crystalline
system was investigated," scientists writing in the Journal of
Physical Chemistry B report.

"The main structural parameters have been calculated and compared with
experimental data. We obtain two types of PDADMAC conformation, a more
folded structure A and a structure B where the PDADMAC molecule is
adsorbed at the anionic head groups of the surfactant molecules,"
wrote A.H. Poghosyan and colleagues.

The researchers concluded: "The polyelectrolyte-induced coexistence of
two lamellar phases at a concentration of 2-3% of PDADMAC is observed,
which is in agreement with experimental findings."

Poghosyan and colleagues published their study in the Journal of
Physical Chemistry B (Molecular Dynamics Study of
Poly(Diallyldimethylammonium chloride) (PDADMAC)/Sodium Dodecyl
Sulfate (SDS)/Decanol/Water Systems. Journal of Physical Chemistry B,
2009;113(5):1303-1310).

Additional information can be obtained by contacting A.H. Poghosyan,
National Academy Science, International Science Education Center, M
Baghramyan Avenue 24D, Yerevan 0019, Armenia.

The publisher of the Journal of Physical Chemistry B can be contacted
at: American Chemical Society, 1155 16th St., NW, Washington, DC
20036, USA.