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Full-Text Articles in Engineering
Comparison Of Interdiffusion At Polystyrene–Poly(Vinyl Methyl Ether) And Polystyrene–Poly(Isobutyl Vinyl Ether) Interfaces, Esmaiel Jabbari, Nikolaos Peppas
Comparison Of Interdiffusion At Polystyrene–Poly(Vinyl Methyl Ether) And Polystyrene–Poly(Isobutyl Vinyl Ether) Interfaces, Esmaiel Jabbari, Nikolaos Peppas
Esmaiel Jabbari
No abstract provided.
Synthesis Of Omega-Sulfonated Polystyrene Via Reversible Addition Fragmentation Chain Transfer Polymerization And Postpolymerization Modification, Lei Feng, Kevin Cavicchi, Bryan Katzenmeyer, Chrys Wesdemiotis
Synthesis Of Omega-Sulfonated Polystyrene Via Reversible Addition Fragmentation Chain Transfer Polymerization And Postpolymerization Modification, Lei Feng, Kevin Cavicchi, Bryan Katzenmeyer, Chrys Wesdemiotis
Kevin Cavicchi
The synthesis of chain-end sulfonated polystyrene [PS (ω-sulfonated PS)] by reversible addition fragmentation chain transfer (RAFT) polymerization followed by postpolymerization modification was investigated by two methods. In the first method, the polymer was converted to a thiol-terminated polymer by aminolysis. This polymer was then sulfonated by oxidation of the thiol end-group with m-chloroperoxybenzoic acid (m-CPBA) to produce a sulfonic acid end-group. In the second method, the RAFT-polymerized polymer was directly sulfonated by oxidation with m-CPBA. After purification by column chromatography, ω-sulfonated PS was obtained by both methods with greater than 95% end-group functionality as measured by titration. The sulfonic acid …
Garland Formation Process In Electrospinning, Yu Xin, Darrell Reneker
Garland Formation Process In Electrospinning, Yu Xin, Darrell Reneker
Darrell Hyson Reneker
The electrospinning technique has become a widely used method to produce nanofibers. Much experimental and theoretical work has been done to investigate the electrospinning process. A typical path of a single jet of polymer solution begins with a straight segment, and then a bending instability generates coils inside a cone shaped envelope. The jet elongates and becomes thinner, and dries into a nanofiber. Polystyrene solutions with different salt concentrations were electrospun to investigate the effect of changing the electrical conductivity on the fibers that were formed. Salt increased the conductivity of the solution and smooth fibers formed. Electrospinning a polystyrene …
Hierarchical Polystyrene Patterns Produced By Electrospinning, Yu Xin, Darrell Reneker
Hierarchical Polystyrene Patterns Produced By Electrospinning, Yu Xin, Darrell Reneker
Darrell Hyson Reneker
When a 25 wt% polystyrene solution was electrospun at relatively low applied voltage, the bending instability initiated, grew and disappeared, repeatedly. Upon further lowering of the applied voltage, the bending instability died immediately after it started and only a straight electrified jet was observed. By manipulating the bending instability of the jet, uniform polystyrene hierarchical patterns were produced by a buckling process. The observed buckling patterns are similar to those of a gravity-driven jet. The conditions for producing buckled polystyrene patterns are reproducible. These small scale buckled polymer patterns can be made very long and uniform. The size of the …