title: Compartmentalized photoreactions within compositionally anisotropic Janus microstructures.
abstract: We demonstrate spatially controlled photoreactions within bicompartmental microparticles and microfibers. Selective photoreactions are achieved by anisotropic incorporation of photocrosslinkable poly(vinyl cinnamate) in one compartment of either colloids or microfibers. Prior to photoreaction, bicompartmental particles, and fibers were prepared by EHD co-jetting of two compositionally distinct polymer solutions. Physical and chemical anisotropy was confirmed by confocal laser scanning microscopy, Fourier-transformed infrared spectroscopy, and scanning electron microscopy. The data indicate adjustment of polymer concentrations of the jetting solutions to be the determining factors for particle and fiber structures. Subsequent exposure of poly(vinyl cinnamate)-based particles and fibers to UV light at 254 nm resulted in spatially controlled crosslinking. Treatment of the crosslinked bicompartmental colloids with chloroform produced half-moon shaped objects. These hemishells exhibited a distinct porous morphology with pore sizes in the range of 70 nm. Based on this novel synthetic approach, Janus-type particles and fibers can be prepared by EHD co-jetting and can be selectively photocrosslinked without the need for masks or selective laser writing.
authors: Department of Chemical Engineering, Macromolecular Science and Engineering, and Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors: Kyung Jin
authors: KJ
authors: Lee
authors: Sangyeul
authors: S
authors: Hwang
authors: Jaewon
authors: J
authors: Yoon
authors: Srijanani
authors: S
authors: Bhaskar
authors: Tae-Hong
authors: TH
authors: Park
authors: Joerg
authors: J
authors: Lahann
mesh_terms: D016880:Anisotropy; D003102:Colloids / Q000737:chemistry*; D008863:Microspheres; D036103:Nanotechnology; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry
chemical_list: D003102:Colloids; D011108:Polymers; D012996:Solutions