title: Structural reorganization of cylindrical nanoparticles triggered by polylactide stereocomplexation.
abstract: Co-crystallization of polymers with different configurations/tacticities provides access to materials with enhanced performance. The stereocomplexation of isotactic poly(L-lactide) and poly(D-lactide) has led to improved properties compared with each homochiral material. Herein, we report the preparation of stereocomplex micelles from a mixture of poly(L-lactide)-b-poly(acrylic acid) and poly(D-lactide)-b-poly(acrylic acid) diblock copolymers in water via crystallization-driven self-assembly. During the formation of these stereocomplex micelles, an unexpected morphological transition results in the formation of dense crystalline spherical micelles rather than cylinders. Furthermore, mixture of cylinders with opposite homochirality in either THF/H2O mixtures or in pure water at 65 °C leads to disassembly into stereocomplexed spherical micelles. Similarly, a transition is also observed in a related PEO-b-PLLA/PEO-b-PDLA system, demonstrating wider applicability. This new mechanism for morphological reorganization, through competitive crystallization and stereocomplexation and without the requirement for an external stimulus, allows for new opportunities in controlled release and delivery applications.
authors.affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Anaïs
authors.initials: A
authors.lastname: Pitto-Barry
authors.affiliation: Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia.
authors.forename: Nigel
authors.initials: N
authors.lastname: Kirby
authors.affiliation: 1] Department of Materials Engineering, Monash University, Clayton, Melbourne, Victoria 3800, Australia [2] School of Science and Technology, University of New England, New England, New South Wales 2351 Australia.
authors.forename: Tara L
authors.initials: TL
authors.lastname: Schiller
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: M Adam
authors.initials: MA
authors.lastname: Dyson
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Sloan
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Neil R
authors.initials: NR
authors.lastname: Wilson
authors.affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Rachel K
authors.initials: RK
authors.lastname: O'Reilly
authors.affiliation: 1] Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK [2] Department of Materials Engineering, Monash University, Clayton, Melbourne, Victoria 3800, Australia.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Dove
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003460:Crystallization; D003692:Delayed-Action Preparations; D005663:Furans / Q000737:chemistry*; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011091:Polyesters / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D005663:Furans; D008823:Micelles; D011091:Polyesters; D014867:Water; C018674:tetrahydrofuran; C033616:poly(lactide)