CO2-responsive TX-100 emulsion for selective synthesis of 1D or 3D gold

Abstract

The effect of CO 2 on the properties of water/poly(oxyethylene)iso-octylphenyl ether (TX-100)/ isooctane emulsions was investigated by direct observation, small angle X-ray scattering (SAXS), and UV-vis spectroscopy at 303.2 K in the pressure range 0-5 MPa. It was demonstrated that the droplet size of the emulsion was sensitive to the pressure of CO 2 , and the droplet size can be tuned in a wide range from the micron to the nanometre scale. When the CO 2 pressure was 3.90 MPa, the droplet size reached a minimum value of 92 nm. To demonstrate the utilization of the CO 2 -responsive water/TX-100/isooctane emulsion, gold particles were synthesized using HAuCl 4 as a gold precursor and TX-100 as a reducing reagent. It was shown that gold particles with different morphologies, such as nanowires, nanorods, and polyhedral nanocrystals could be synthesized by controlling the pressure of CO 2 .

Mechanistic Aspects of Aqueous Heterogeneous Radical Polymerization of Styrene under Compressed CO2

“…As the pressure was further increased, the emulsion once again became translucent and finally turbid again at pressures beyond 10.0 MPa. This behavior is consistent with previous work on CO 2 pressurization of oil‐in‐water and water‐in‐oil emulsions …”

Magnetic Control over Liquid Surface Properties with Responsive Surfactants

“…Surfactants responsive to pH,1 temperature,2 CO 2 ,3 and light4 are well known. Here we report for the first time ionic liquid surfactants that are magneto‐responsive, thus offering the potential to perturb liquid emulsions simply by the application of an external magnetic field.…”

Radical polymerization of miniemulsions induced by compressed gases

“…36 The transparent emulsion formed via CO 2 pressurization of TX-100 (poly(oxyethylene)iso-octylphenyl ether)/water/ isooctane at P T ¼ 3.90 MPa was characterized by small-angle Xray scattering (SAXS), yielding spherical droplets of diameter 92 nm. 41 However, a typical miniemulsion with a diameter of 92 nm is not transparent but milky white. 1 Compressed gas-induced miniemulsion polymerization entails pressurization of a coarse macroemulsion to moderate pressure followed by radical polymerization.…”