Reversible aggregation kinetics of poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) in aqueous solutions revealed by elastic light scattering spectroscopy

Abstract

Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) [P(NIPAM-co-NVP)] copolymers with different content of N-vinylpyrrolidone (NVP) were synthesized, and reversible aggregation kinetics of the copolymers in aqueous solutions was investigated with elastic light scattering (ELS) spectra. The results indicated that the apparent activation energy of aggregation process during heating and dissociation process during cooling increased with the NVP content increasing. The phase transition temperature also increased as the content of NVP increased, suggesting that the hydrophilic nature of NVP strongly affected the phase behavior of the copolymer solutions. The higher the content of NVP, the higher the temperature required to break the balance between the hydrophilic and hydrophobic interaction. Besides, during heating and cooling process, the phase transition hysteresis of P(NIPAM-co-NVP) chains decreased when the hydrophilic comonomer increased.

Keywords

poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) / kinetics / aggregation / hydrophilicity / elastic light scattering spectra

References

[1] McKee JR, Ladmiral V, Niskanen J, . Synthesis of Sterically-Stabilized Polystyrene Latexes Using Well-defined Thermoresponsive Poly(N-isopropylacrylamide) Macromonomers[J]. Macromolecules, 2011, 44(19): 7 692-7 703.

[2] Huber DL, Manginell RP, Samara MA, . Programmed Adsorption and Release of Proteins in a Microfluidic Device[J]. Science, 2003, 301(5631): 352-354.

[3] Song F, Wang XL, Wang YZ Poly (N-isopropylacrylamide)/poly (ethylene oxide) Blend Nanofibrous Scaffolds: Thermo-responsive Carrier for Controlled Drug Release[J]. Colloid.Surface. B: Biointerfaces, 2011, 88(2): 749-754.

[4] Molina MA, Rivarola CR, Barbero CA Effect of Copolymerization and Semi-interpenetration with Conducting Polyanilines on the Physicochemical Properties of Poly(N-isopropylacrylamide) Based Thermosensitive Hydrogels[J]. Euro.Polym.J., 2011, 47(10): 1 977-1 984.

[5] Winnik FM Fluorescence Studies of Aqueous Solutions of poly(N-isopropylacrylamide) below and above Their LCST[J]. Macromolecules, 1990, 23(1): 233-242.

[6] Sakellariou P Theta Temperature of Poly(N-vinyl pyrrolidone) in Water[J]. Polymer, 1992, 33(6): 1 339-1 342.

[7] Zhang GZ, Wu C Folding and Formation of Mesoglobules in Dilute Copolymer Solutions[J]. Adv.Polym.Sci., 2005, 195: 1-76.

[8] Gunari N, Balazs AC, Walker GC Force-induced Globule-coil Transition in Single Polystyrene Chains in Water[J]. J.Am.Chem.Soc., 2007, 129(33): 10 046-10 047.

[9] Hu HQ, Li JY, Zhang CG, . Phase Behavior Study of PEB/PES Blend by Time Resolved Laser Light Scattering[J]. Polymer, 2010, 51(20): 4619-4626.

[10] Zheng Q, Tan KT, Peng M, . Study on the Phase Separation of Thermoplastic-modified Epoxy Systems by Time-resolved Small-angle Laser Light Scattering[J]. J.Appl.Polym.Sci., 2002, 85(5): 950-956.

[11] Nakazono T, Ozaki A, Matsumoto A Phase Separation and Thermal Aging Behavior of Styrene-butadiene Rubber Vulcanizates Using Liquid Polymers as Plasticizers Studied by Differential Scanning Calorimetry and Dynamic Mechanical Spectroscopy[J]. J.Appl.Polym. Sci., 2011, 120(1): 434-440.

[12] Gotzen NA, Huth H, Schick C, . Phase Separation in Polymer Blend thin Films Studied by Differential AC Chip Calorimetry[J]. Polymer, 2010, 51(3): 647-654.

[13] Ding YW, Ye XD, Zhang GZ Microcalorimetric Investigation on Aggregation and Dissolution of Poly(N-isopropylacrylamide) Chains in Water[J]. Macromolecules, 2005, 38(3): 904-908.

[14] Zhang JM, Li CW, Duan YX, . Glass Transition and Disorder-toorder Phase Transition Behavior of Poly(l-lactic acid) Revealed by Infrared Spectroscopy[J]. Vib.Spectrosc., 2010, 53(2): 307-310.

[15] Yamashita M, Hirao A, Kato M The Effect of Pressure on the Phase Transition Behavior of Tridecane, Pentadecane, and Heptadecane: A Fourier Transform Infrared Spectroscopy Study[J]. J.Chem.Phys., 2011, 134: 144503

[16] Cheng H, Shen L, Wu C LLS and FTIR Studies on the Hysteresis in Association and Dissociation of Poly(N-isopropylacrylamide) Chains in Water[J]. Macromolecules, 2006, 39(6): 2 325-2 329.

[17] Lu W, Fernández BS, Yu Y, . Resonance Light Scattering and Derived Techniques in Analytical Chemistry: Past, Present, and Future[J]. Microchim. Acta, 2007, 158(2): 29-58.

[18] Zhang WZ, Chen XD, Luo WA, . Study of Phase Separation of Poly(vinyl methyl ether) Aqueous Solutions with Rayleigh Scattering Technique[J]. Macromolecules, 2009, 42(5): 1 720-1 725.

[19] Katsumoto Y, Tanaka T, Sato H, . Conformational Change of poly(N-isopropylacrylamide) during the Coil-globule Transition Investigated by Attenuated Total Reflection/Infrared Spectroscopy and Density Functional Theory Calculation[J]. J.Phys.Chem. A, 2002, 106(14): 3 429-3 435.

[20] Lowe TL, Virtanen J, Tenhu H Interactions of Drugs and Spin Probes with Hydrophobically Modified Polyelectrolyte Hydrogels Based on N-isopropylacrylamide[J]. Polymer, 1999, 40(10): 2 595-2 603.

[21] Luo WA, Liao ZF, Yang J, . Cold-crystallization of Poly (trimethylene terephthalate) Studied by Photoluminescence of Its Amorphous Portion[J]. Macromolecules, 2008, 41(20): 7513-7518.

[22] Siu MH, He C, Wu C Formation of Mesoglobular Phase of Amphiphilic Copolymer Chains in Dilute Solution: Effect of Comonomer Distribution[J]. Macromolecules, 2003, 36(17): 6 588-6 592.

[23] Chen HW, Li JF, Ding YW, . Folding and Unfolding of Individual PNIPAM-g-PEO Copolymer Chains in Dilute Aqueous Solutions[J]. Macromolecules, 2005, 38(10): 4 403-4 408.

[24] Siu MH, Zhang GZ, Wu C Effect of Comonomer Distribution on the Coil-to-Globule Transition of a Single AB Copolymer Chain in Dilute Solution[J]. Macromolecules, 2002, 35(7): 2 723-2 727.