title: Molecular orientation evolution and solvent evaporation during electrospinning of atactic polystyrene using real-time Raman spectroscopy.
abstract: Real-time Raman spectroscopy was successfully utilized to monitor solvent evaporation and molecular orientation during electrospinning of atactic polystyrene (a-PS). The use of a binary solvent system of N,N-dimethyl formamide (DMF) and tetrahydrofuran (THF) provided a stable, straight jet during the experiment. The prominent Raman bands centered at 866 cm(-1), 914 cm(-1), and 1004 cm(-1), unique to DMF, THF, and a-PS, respectively, were used to monitor solvent concentration changes along the electrospinning jet for two different a-PS solutions. In addition, the changes in relative intensity for the radial skeletal ring vibration of the aromatic group of a-PS at 623 cm(-1) in two different polarization geometries, ZZ and YY, were monitored for orientation information. This study reports the first quantitative vibrational spectroscopic measurement during the electrospinning process. A significant change in concentration and orientation was observed during the process. The changes are explained in relation to the electrospinning process.
authors.affiliation: Department of Materials Science and Engineering, University of Delaware, Newark, 19716, USA.
authors.forename: Giriprasath
authors.initials: G
authors.lastname: Gururajan
authors.forename: Carl B
authors.initials: CB
authors.lastname: Giller
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Snively
authors.forename: D Bruce
authors.initials: DB
authors.lastname: Chase
authors.forename: John F
authors.initials: JF
authors.lastname: Rabolt
mesh_terms: D004126:Dimethylformamide / Q000737:chemistry; D004867:Equipment Design; D005559:Formamides / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D011137:Polystyrenes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D005559:Formamides; D005663:Furans; D011137:Polystyrenes; D012997:Solvents; C018674:tetrahydrofuran; C031066:formamide; D004126:Dimethylformamide