Abstract
Zwitterionic microspheres of poly2-(dimethylamino) ethyl methacrylate (PDMAEMA) block polymethacrylic acid (MAA) were prepared by RAFT dispersion polymerization in alcohols. 4-Cyano-4-(phenylcarbonothioylthio) pentanoic acid (CPDB) was used as the RAFT agent. 2,2′-Azobis(2,4-dimethyl) valeronitrile (V65) was used as the initiator, and PDMAEMA-CPDB was used as the macro-chain transfer agent (CTA). 1HNMR was applied to determine the polymerization degrees of both PDMAEMA-CTA and PDMAEMA-b-PMAA. SEM, dynamic light scattering (DLS), and small-angle X-ray diffraction (SAX) were employed to characterize the microspheres. It was observed that the polarity of alcohols impacted the partition of MAA and V65 between the mini-droplets of PDMAEMA-CTA/MAA complexes and the continuous phase, thereby affected on the diameters of microspheres, the total conversion of MAA, and the polymerization degree of PMAA in the copolymers. For example, in methanol, the smallest diameter and polymerization degree of PMAA in the block copolymers were obtained, whereas the total conversion of MAA of the RAFT polymerization system was the highest. Most of RAFT polymerization of MAA occurred nearby PDMAEMA-CTA chains; thus, PDMAEMA-CTA acted as a template to regulate the length of PMAA in the copolymers. pH-sensitive characteristics of microspheres were dependent to the extra length of PDMAEMA-CTA, i.e., the difference of lengths between two blocks. When the length of PMAA was too short, e.g., PDMAEMA600-b-PMAA87, or the length of PMAA was closed to that of PDMAEMA, e.g., PDMAEMA79-b-PMAA93 and PDMAEMA102-b-PMAA131, the amphoteric characteristics of microspheres disappeared. The self-assembly behavior of diblock copolymers in KCl alcohol-water solution was also determined by the extra length of PDMAEMA. Microspheres turned into nanofibers or nano-ribbons, but for PDMAEMA600-b-PMAA87, the microspheres maintained their original spheric morphology. These results indicated that the charge-screening effects of salts played the key roles in the self-assembly.
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Liu L, Wu CL, Zhang JC, Zhang MM, Liu YW, Wang XJ, Fu GQ (2008) Controlled polymerization of 2-(diethylamino)ethyl methacrylate and its block copolymer with N-isopropylacrylamide by RAFT polymerization. J Polym Sci A Polym Chem 46(10):3294–3305
Derry MJ, Fielding LA, Armes SP (2016) Polymerization-induced self-assembly of block copolymer nanoparticles via RAFT non-aqueous dispersion polymerization. Prog Polym Sci 52:1–18
Hu LZ, Wang YH, Yin Q, Du K, Yin QJ (2019) Multiple morphologies of a poly(methyl methacrylate)-block-poly(N,N-dimethyl aminoethyl methacrylate) copolymer with pH-responsiveness and thermoresponsiveness. J Appl Polym Sci 136(38):10
Agut W, Brulet A, Schatz C, Taton D, Lecommandoux S (2010) pH and temperature responsive polymeric micelles and polymersomes by self-assembly of poly 2-(dimethylamino)ethyl methacrylate-b-poly(glutamic acid) double hydrophilic block copolymers. Langmuir 26(13):10546–10554
Canning SL, Smith GN, Armes SP (2016) A critical appraisal of RAFT-mediated polymerization-induced self assembly. Macromolecules 49(6):1985–2001
Klaikherd A, Nagamani C, Thayumanavan S (2009) Multi-stimuli sensitive amphiphilic block copolymer assemblies. J Am Chem Soc 131(13):4830–4838
Penfold NJW, Yeow J, Boyer C, Armes SP (2019) Emerging trends in polymerization-induced self-assembly. ACS Macro Lett 8(8):1029–1054
Warren NJ, Armes SP (2014) Polymerization-induced self-assembly of block copolymer nano-objects via RAFT aqueous dispersion polymerization. J Am Chem Soc 136(29):10174–10185
Perrier S (2017) 50th anniversary perspective: RAFT polymerization-a user guide. Macromolecules 50(19):7433–7447
Grubbs RB, Grubbs RH (2017) 50th anniversary perspective: living polymerization-emphasizing the molecule in macromolecules. Macromolecules 50(18):6979–6997
Lombardo D, Kiselev MA, Magazu S, Calandra P (2015) Amphiphiles self-assembly: basic concepts and future perspectives of supramolecular approaches. Adv Condens Matter Phys 2015:22
Palmiero UC, Maraldi M, Manfredini N, Moscatelli D (2018) Zwitterionic polyester-based nanoparticles with tunable size, polymer molecular weight, and degradation time. Biomacromolecules 19(4):1314–1323
Sponchioni M, Bassam PR, Moscatelli D, Arosio P, Palmiero UC (2019) Biodegradable zwitterionic nanoparticles with tunable UCST-type phase separation under physiological conditions. Nanoscale 11(35):16582–16591
Zhan K, Zhang H, Li M, Chen YL, Chen GX, Liu JX, Wu M, Ni HM (2014) Charges of soluble amphiphiles and particles: random and diblock copolymerizations of MAA/AAm, MAA/St, and MAA/4VP in ethanol. Colloid Polym Sci 292(7):1553–1565
Ni HM, Liu JX, Shi K, Wu M, Yang YD, Zhang LJ (2016) PMAA-based RAFT dispersion polymerization of MMA in ethanol: conductivity, block length and self-assembly. RSC Adv 6(63):58218–58225
Li M, Ni HM (2011) Conductimetry study of the precipitation polymerization of acrylamide and methacrylic acid in ethanol by using V-65 as initiator. Proceedings of 2011 International Conference on Remote Sensing, Environment and Transportation Engineering, pp 6707–6710
Fayer MD (2012) Dynamics of water interacting with interfaces, molecules, and ions. Acc Chem Res 45(1):3–14
Bonn M, Bakker HJ, Rago G, Pouzy F, Siekierzycka JR, Brouwer AM, Bonn D (2009) Suppression of proton mobility by hydrophobic hydration. J Am Chem Soc 131(47):17070
van der Loop TH, Ottosson N, Vad T, Sager WFC, Bakker HJ, Woutersen S (2017) Communication: slow proton-charge diffusion in nanoconfined water. J Chem Phys 146(13):5
Sloan Jr ED (2003) Fundamental principles and applications of natural gas hydrates. Nature 426:353–359
Lee JS, Feijen J (2012) Polymersomes for drug delivery: design, formation and characterization. J Control Release 161(2):473–483
Tanner P, Baumann P, Enea R, Onaca O, Palivan C, Meier W (2011) Polymeric vesicles: from drug carriers to nanoreactors and artificial organelles. Acc Chem Res 44(10):1039–1049
Convertine AJ, Benoit DSW, Duvall CL, Hoffman AS, Stayton PS (2009) Development of a novel endosomolytic diblock copolymer for siRNA delivery. J Control Release 133(3):221–229
Taylor ME, Lounder SJ, Asatekin A, Panzer MJ (2020) Synthesis and self-assembly of fully zwitterionic triblock copolymers. ACS Mater Lett 2(3):261–265
Petroff MG, Garcia EA, Herrera-Alonso M, Bevan MA (2019) Ionic strength-dependent interactions and dimensions of adsorbed zwitterionic copolymers. Langmuir 35(14):4976–4985
Wang F, Yang JF, Zhao J (2015) Understanding anti-polyelectrolyte behavior of a well-defined polyzwitterion at the single-chain level. Polym Int 64(8):999–1005
Henmei N, Wu M, Li M, Wang HL, Sun YM (2010) Quasi-static particle formation of poly(acrylamide/methacrylic acid) in ethanol by using V-65 as initiator. Polym Chem 1(6):899–907
Ni HM, Du YZ, Ma GH, Nagai M, Omi S (2001) Mechanism of soap-free emulsion polymerization of styrene and 4-vinylpyridine: characteristics of reaction in the monomer phase, aqueous phase, and their interface. Macromolecules 34(19):6577–6585
Ni HM, Ma GH, Nagai M, Omi S (2001) Effects of ethyl acetate on the soap-free emulsion polymerization of 4-vinylpyridine and styrene. I. Aspects of the mechanism. J Appl Polym Sci 82(11):2679–2691
Ni HM, Ma GH, Nagai M, Omi S (2001) Effects of ethyl acetate on the soap-free emulsion polymerization of 4-vinylpyridine and styrene. J Appl Polym Sci 80(11):1988–2001
Kashiwabara M, Fujimoto K, Kawaguchi H (1995) Preparation of monodisperse, reactive hydrogel microspheres and their amphoterization. Colloid Polym Sci 273(4):339–345
Ni HM, Kawaguchi H, Endo T (2007) Preparation and application of amphoteric hydrogel microsphere with novel pH-volume transition. Macromolecules 40:6370–6381
Chen GX, Liu JX, Yang YD, Zhang LJ, Wu M, Ni HM (2015) Preparation of pH-sensitive nanoparticles of poly (methacrylic acid) (PMAA)/poly (vinyl pyrrolidone) (PVP) by ATRP-template miniemulsion polymerization in the aqueous solution. Colloid Polym Sci 293(7):2035–2044
Yang CC, Meng D, Zhan K, Chen YL, Zhang H, Wu M, Ni HM (2014) ATRP-template dispersion polymerization of methacrylic acid/PVP. Chin J Polym Sci 32(4):476–487
Ilavsky J, Jemian PR (2009) Irena: tool suite for modeling and analysis of small-angle scattering. J Appl Crystallogr 42:347–353
Gurung J, Pulikkal AK (2019) Self-assembly and thermodynamic parameters of amitriptyline hydrochloride in polar organic solvent-water mixed media. J Chem Eng Data 64(10):4493–4500
Zhang C, Maric M (2011) Synthesis of stimuli-responsive, water-soluble poly 2-(dimethylamino)ethyl methacrylate/styrene statistical copolymers by nitroxide mediated polymerization. Polymers 3(3):1398–1422
Grzetic DJ, Delaney KT, Fredrickson GH (2019) Field-theoretic study of salt-induced order and disorder in a polarizable diblock copolymer. ACS Macro Lett 8(8):962–967
Wesley RD, Dreiss CA, Cosgrove T, Armes SP, Thompson L, Baines FL, Billingham NC (2005) Structure of a hydrophilic-hydrophobic block copolymer and its interactions with salt and an anionic surfactant. Langmuir 21(11):4856–4861
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Xia, Y., Xu, X., Yu, H. et al. Preparation of zwitterionic microspheres of PDMAEMA-b-PMAA by RAFT dispersion polymerization in alcohol, their pH-sensitivity in water, and self-assembly in KCl solution. Colloid Polym Sci 299, 663–674 (2021). https://doi.org/10.1007/s00396-020-04790-6
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DOI: https://doi.org/10.1007/s00396-020-04790-6