Interaction between Surfactant and Poly(N-vinylcaprolactam) Microgels

Abstract

Narrowly distributed spherical poly(N-vinylcaprolactam) (PNVC) microgels were prepared by precipitation polymerization in water. The effect of both anionic (sodium dodecyl sulfate, SDS) and cationic (N-dodecylpyridinium bromide, DPB) surfactants on the swelling and shrinking of the microgels were investigated by laser light scattering (LLS). Our results showed that the microgels gradually shrank to the collapsed state when the temperature increased from 20 to ∼38 °C. The addition of anionic surfactant caused an extra swelling of the microgels and shifted the collapsing temperature higher, whereas the addition of cationic surfactant has different effects on the swelling and shrinking of the microgels prepared by using different initiators, depending on whether the decomposed fragments of the initiator are ionic or neutral. Our results clearly showed that the ionic groups introduced into polymer gels from the initiators should be taken into consideration in the study of the surfactant/gel interaction.

Study on hydration of poly(N-vinylcaprolactam) microgels by near-IR and mid-IR spectroscopy

“…Synthesis PVCL microgel was prepared from emulsion polymerization, using a method similar to that by Gao et al [9]. The reaction was carried out in a 200 mL two-neck flask equipped with a reflux condenser and a mechanical stirrer device.…”

“…Another reason why it is attractive is that its amide group will not produce small compounds after hydrolysis, which makes it suitable for biomedical applications [7,8]. Gao et al [9] proposed a precipitation polymerization method to get PVCL microgels, and the effect of surfactant on it was investigated. Laukkanen et al [10] prepared PVCL microgel particles grafted with amphiphilic chains with a method similar to that of Gao's.…”

Thermosensitive graft copolymers of an amphiphilic macromonomer and N-vinylcaprolactam: synthesis and solution properties in dilute aqueous solutions below and above the LCST

“…Accurate estimes of M agg w are somewhat difficult because of the uncertainty of the increment of refractive index, dn/dc, for the collapsed polymer at 50 8C. We calculated M agg w values using two different dn/dc values: 0.176 cm 3 /g, the value measured for PVCL-g-18 in water at 20 8C and 0.232 cm 3 /g, a literature value for a collapsed PVCL microgel at 40 8C [39]. Both values of M agg w are listed in Table 4, together with r, the density of the particles (rZ M agg w =ðN A ð4=3ÞpR 3 h Þ).…”

Interpolymer complexes of poly(acrylic acid) nanogels with some non-ionic polymers in aqueous solutions

“…microgels and nanogels [11][12][13][14][15][16][17][18][19][20]. The microgel and nanogel particles are of particular interest because they exhibit intrinsic properties of gels combined with the properties of colloids.…”

“…The microgel and nanogel particles are of particular interest because they exhibit intrinsic properties of gels combined with the properties of colloids. There are several studies devoted to interactions of micro and nanogels with drug molecules and proteins [11,12,14], surfactants [13] as well as living cells [16]. However the information about complexation of micro and nanogels with linear polymers via hydrogen bonding is insufficient and to the best of our knowledge is limited to one research paper only [20].…”