Effect of Varying Additives on Aqueous Solution of PEO-PPO-PEO Tri-block Copolymer

Abstract

The effect of addition of salt potassium chloride (KCl) and detergent sodium dodecyl sulfate (SDS) on the aqueous solution of PEO‐PPO‐PEO (polyethylene oxide‐polypropylene oxide‐polyethylene oxide) tri‐block copolymer, i.e. (EO)103(PO)39(EO)103 Pluronics F88 has been carried out. The concentration of F88 was fixed at 5 wt‐% and the concentrations of KCl and SDS were varying in the range of 0.05 to 1.5 M and 0.001 to 0.125 M, respectively. Small‐angle neutron scattering (SANS) experiments were carried out using 36 m SANS spectrometer at Neutron Scattering Laboratory, Serpong (SMARTer), Indonesia. The wavelength of neutron beam was 3.90 A and the experiments were performed at two different sample‐to‐detector distances of 2 m and 8 m. A 3He of 128×128 two‐dimensional position sensitive detector (2D‐PSD) with a beam stopper of 60 mm in diameter was used to detect the scattered beam in the range of 0.008<Q(A−1)<0.25. All measurements were performed at room temperature. It is observed that increasing the concentration of the above additives induced the micellization of block copolymers to form a core‐shell micelle structure.