|
Smart Response nano- gel synthesis of nanomaterials , drug delivery , cosmetics and other fields has wide application prospect. In this paper, soap-free emulsion polymerization method to N-isopropyl acrylamide (NIPAM) for the temperature-sensitive monomer , methacrylic acylated sulfadiazine (SD) or allylamine (AM) for the pH-sensitive monomers, synthetic two monodisperse , temperature and pH -sensitive nanogels ; using DLS, TEM and other methods nanogels were characterized , the effects of temperature , pH, ionic strength of the two nano- particle gel water dispersion system effects ; further nanogels used in Pickering nanoemulsion build, and initially explored nano gel emulsion stability mechanism . 1) p (NIPAM-co-SD) nanogels : ( 1 ) As the temperature increases, the particle size decreases, the phase transition temperature in the range between 33.0 ~ 34.0 ℃ ; in 0.05 ~ 0.8 mol / L of NaCl solution , the particle diameter were about 200 nm , the colloidal system than pure small size ; ( 2 ) at 25.0 ℃ , when the pH is in the range of 6.00 ~ 7.40 , with the pH increases, the ionization degree increases, the colloidal particle size increases ; pH is between 1.50 to 6.00 , pH decreased, the particle size increases ; (3) TEM morphology observation that nanogels spherical morphology , the monomer feed ratio on its internal shape has some influence ; 2) p (NIPAM-co-AM) nanogels : (1) p (NIPAM-co-AM) nanogels size decreases with increasing temperature ; while under the same temperature conditions , at a pH value of between 6.00 ~ 7.40 , the particle size decreases as the pH increases ; at between pH 4.00 ~ 6.00 , the particle size increases with the increase of pH ; ( 2) TEM morphology observation that nanogels uniform size , network structure for the spherical particles. 3 ) using nano- gel preparation of Pickering emulsions. Control through process and prescription , can be prepared from 100 nm average particle size of the emulsion to several micrometers . The prepared Pickering emulsions were TEM morphology, optical imaging and fluorescence imaging studies ; right nanogels temperature-sensitive emulsion , pH sensitivity and stability were studied. In addition , this paper also uses hydrogen damage experiments on emulsion formation mechanism was discussed .
|