TY - JOUR
T1 - Alkanol-induced micelles of a very hydrophilic eo-po-eo block copolymer
T2 - Characterization by spectral and scattering methods
AU - Parmar, Arpan
AU - Bharatiya, Bhavesh
AU - Patel, Keyur
AU - Aswal, Vinod
AU - Bahadur, Pratap
PY - 2013/1/1
Y1 - 2013/1/1
N2 - The aqueous solution behavior of a PEO-PPO-PEO block copolymer (EO 103PO39EO103), was investigated in the presence of aliphatic alkanols (C2, C4, C6 and C 8). The non-associated polymer chains remain extremely hydrated in water, but aggregation in the form of spherical micelles was evidenced, triggered by the interaction of polymer chains with hydrophobic alkanol. We assume that the hydrophobic interaction between the PPO block of the copolymer and alkanol promotes micellization, which increases further with the introduction of higher chain length species. The critical micellization temperature (CMT), as measured by UV-visible spectroscopy, indicates an interaction of polymer chains with the alkanol bearing a higher chain length, which triggers aggregation. The micelles were characterized by small angle neutron scattering to elucidate the size and related micellar parameters. The gradual increase in the alkanol content increases the aggregation number, though the micelles were spherical in shape. We conclude that ethanol, due to its preferential solubility in the aqueous phase, does not affect the aggregation. The alkanols with chain lengths of C4-C8 chain, interact with the PPO block through hydrophobic interaction and shifts the CMTs to lower values. The combined effect of inorganic salt (NaCl) and alkanols show enhanced micellar properties.
AB - The aqueous solution behavior of a PEO-PPO-PEO block copolymer (EO 103PO39EO103), was investigated in the presence of aliphatic alkanols (C2, C4, C6 and C 8). The non-associated polymer chains remain extremely hydrated in water, but aggregation in the form of spherical micelles was evidenced, triggered by the interaction of polymer chains with hydrophobic alkanol. We assume that the hydrophobic interaction between the PPO block of the copolymer and alkanol promotes micellization, which increases further with the introduction of higher chain length species. The critical micellization temperature (CMT), as measured by UV-visible spectroscopy, indicates an interaction of polymer chains with the alkanol bearing a higher chain length, which triggers aggregation. The micelles were characterized by small angle neutron scattering to elucidate the size and related micellar parameters. The gradual increase in the alkanol content increases the aggregation number, though the micelles were spherical in shape. We conclude that ethanol, due to its preferential solubility in the aqueous phase, does not affect the aggregation. The alkanols with chain lengths of C4-C8 chain, interact with the PPO block through hydrophobic interaction and shifts the CMTs to lower values. The combined effect of inorganic salt (NaCl) and alkanols show enhanced micellar properties.
KW - CMT
KW - Hydrophobic interaction
KW - PEO-PPO-PEO
UR - http://www.scopus.com/inward/record.url?scp=84872377724&partnerID=8YFLogxK
U2 - 10.1007/s11743-012-1365-9
DO - 10.1007/s11743-012-1365-9
M3 - Article (Academic Journal)
AN - SCOPUS:84872377724
VL - 16
SP - 105
EP - 114
JO - Journal of Surfactants and Detergents
JF - Journal of Surfactants and Detergents
SN - 1097-3958
IS - 1
ER -