Abstract
Swelling properties of doubly temperature sensitive core-shell microgels consisting of two thermosensitive polymers namely poly-N-isopropylacrylamide (PNIPAM) with a lower critical solution temperature (LCST) at ca. 34 °C and poly-N-isopropylmethacrylamide (PNIPMAM) with a LCST of ca. 44 °C have been investigated by small-angle neutron scattering (SANS). Two types of microgels with different core-shell composition were studied: PNIPAM-core — PNIPMAM-shell microgels as well as a microgel with inverse structure, i.e. PNIPMAM-core — PNIPAM-shell. A core-shell form factor has been employed to evaluate the structure and the real space particle structure is expressed by radial density profiles. By this means the influences of composition and temperature on the internal structure have been revealed. At temperatures between the LCSTs the swelling of the PNIPMAM-shell leads to an expansion of the PNIPAM-core. At temperatures below the core LCST, the core cannot swell to its native size (i.e. in the absence of a shell) because the maximum expanded shell network prohibits further swelling. Thus depending on temperature the shell either expands or compresses the core. The inverse PNIPMAM-core — PNIPAM-shell microgel displays qualitatively different behavior. At intermediate temperatures, the segment density of the shell is higher as compared to the core. Since the density ratio of shell and core depends on temperature, such core-shell microgels provide interesting opportunities for encapsulation and controlled release.
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References
Bergbreiter DE, Case BL, Liu Y-S, Caraway JW (1998) Macromolecules 31:6053–6062
Castro Lopez V, Raghavan SL, Snowden MJ (2004) React Funct Polym 58:175–185
Gerlach G, Guenther M, Suchaneck G, Sorber J, Arndt K-F, Richter A (2004) Macromol Symp21:403–410
Cornelius VJ, Snowden MJ, Silver J, Fern GR (2004) React Funct Polym 58:165–173
Senff H, Richtering W (1999) J Chem Phys 111:1705–1711
Kim J, Serpe MJ, Lyon LA (2005) Angew Chem 117:1357–1360
Pelton R (2000) Adv Colloid Interf Sci 85:1–33
Heskins M, Guilett J (1968) Macromol Sci Chem A2(8):1441–1455
Rasmusson M, Vincent B (2004) React Funct Polym 58:203–211
Mielke M, Zimehl R (1998) Ber Bunsenges Phys Chem 102:1698–1704
Hoare T, Pelton R (2004) Macromolecules 37:2544–2550
Nayak S, Lyon LA (2004) Angew Chem 116:6874–6877
Jones CD, Lyon LA (2000) Macromolecules 33:8301–8306
Berndt I, Richtering W (2003) Macromolecules 36:8780–8785
Kratz K, Hellweg T, Eimer W (2001) Polymer 42:6631–6639
Saunders BR (2004) Langmuir 20:3925–3932
Stieger M, Richtering W, Pedersen JS, Lindner P (2004) J Chem Phys 120:6197–6206
Wu X, Pelton RH, Hamielec AE, Woods DR, McPhee W (1994) Colloid Polym Sci 272:467–477
Meyer S, Richtering W (2005) Macromolecules 38:1517–1519
Boyko V, Richter S, Grillo I, Geissler E (2005) Macromolecules 38:5266–5270
Jones CD, Lyon LA (2003) Langmuir 19:4544–4547
Jones CD, Lyon LA (2003) Macromolecules 36:1988–1993
Gan D, Lyon LA (2001) J Am Chem Soc 123:8203–8209
Jones CD, Mc Grath JG, Lyon LA (2004) J Phys Chem B 108:12652–12657
Berndt I, Pedersen JS, Richtering W (2005) J Am Chem Soc 127:9372–9373
Berndt I, Pedersen JS, Lindner P, Richtering W (2006) Langmuir 22:459–468
Berndt I, Pedersen JS, Richtering W (2006) Angew Chem 118:1769–1773
Berndt I, Pedersen JS, Richtering W (2006) Angew Chem Int Ed 45:1737–1741
Pedersen JS (1997) Adv Colloid Interf Sci 70:171–210
Pedersen JS, Posselt D, Mortensen K (1990) J Appl Crystallogr 23:321–333
Berndt I, Popescu C, Wortmann F-J, Richtering W (2006) Angew Chem 118:1099–1102
Berndt I, Popescu C, Wortmann F-J, Richtering W (2006) Angew Chem Int Ed 45:1081–1085
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Berndt, I., Richtering, W., Pedersen, J.S., Lindner, P. (2006). Structure of Doubly Temperature Sensitive Core-Shell Microgels Based on Poly-N-Isopropylacrylamide and Poly-N-Isopropylmethacrylamide. In: Richtering, W. (eds) Smart Colloidal Materials. Progress in Colloid and Polymer Science, vol 133. Springer, Berlin, Heidelberg . https://doi.org/10.1007/3-540-32702-9_6
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DOI: https://doi.org/10.1007/3-540-32702-9_6
Publisher Name: Springer, Berlin, Heidelberg
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