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E u r o s c i c o n C o n f e r e n c e o n
Physical Chemistry and
Analytical Separation Techniques
October 08-09 , 2018
Amsterdam, Nether l ands
Journal of Organic & Inorganic Chemistry
ISSN: 2472-1123
Physical Chemistry and Analytical Separation Techniques 2018
T
he polycarboxybetaine polysulfobetaine double hydrophilic block copolymer, poly (2-((2-(methacryloyloxy) ethyl)
dimethylammonio) acetate)-b-poly (3-((2-(methacryloyloxy) ethyl) di-methylammonio) propane-1-sulfonate) (PGLBT-
b
-PSPE),
was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. The block copolymer was designed
for responding to both temperature and pH. The temperature dependent behaviours in aqueous solution of PGLBT-b-PSPEs were
revealed by observing transmittance variation at λ=400 nm. The transmittance of solutions was gradually increase/decreased over
20
o
C, unlike polysulfobetaine homopolymers or other temperature responsive non-ionic polymers that usually show abrupt transition
within only a few
o
C. Dynamic light scattering studies at transparent or translucent state elucidated that the block copolymer chains
created monodisperse particles (hydrodynamic radius R
h
= 40-60 nm, depended on the chain length) although the both are hydrophilic
components, and the particles turned into individual chains when the solution was transparent. At the intermediate temperature,
highly expanded particles and unimer like small particles were detected simultaneously. (Fig. 1)
1
H NMR measurement showed
disappearances of some signals of PSPE at low temperatures and reappearances by temperature increase, which suggested that
the UCST-type PSPE segments aggregate each other to form core and the PGLBT segments form corona on the particle surface.
Consequently, PGLBT-
b
-PSPE forms polymeric micelles below certain temperature, then gradually disassembled upon heating,
and eventually turned into single chains while the transmittance rises to almost 100%. The structure of particles was identified by
comparing radius of gyration to hydrodynamic radius, Rg/Rh. In micellar region, the shape factor was approximately 0.77 which
anticipates spherical particles and closed to unity just before disassociation which implies hollow or anisotropic structure. Particle
images obtained by TEM met in a good agreement with the light scattering results. Under acidic (pH ~2) condition, zeta potentials of
the particle surface turned into positive from near neutral by protonation of carboxylate unit on PGLBT chains, and large aggregates
made the solution more turbid
Biography
Jongmin Lim is currently pursuing his PhD degree at Kyoto University under the supervision of Prof Hideki Matsuoka. His current research interests focus on the synthesis and
characterizing stimuli responsive double betaine block copolymers. He has received his MS degree in Chemical Engineering in 2011 fromKAIST, South Korea under the guidance
of Prof Bumjoon J Kim before working several years at LG Household and Health Care.
lim.jongmin.33a@st.kyoto-u.ac.jpTemperature and pH responsive double hydrophilic betaine
copolymer: synthesis and investigation of the behaviour
Jongmin Lim
1
, Hideki Matsuoka
1
and Yoshiyuki Saruwatari
2
1
Kyoto University, Japan
2
Osaka Organic Chemical Industry Ltd, Japan
Jongmin Lim et al., J Org Inorg Chem 2018 Volume: 4
DOI: 10.21767/2472-1123-C6-017
Figure 1:
Variations of hydrodynamic radii of GLBT86
derivative PGLBT-b-PSPEs
Figure 2:
TEM image of GLBT86-b-SPE164 (scale bar:
1μm)