Cover Picture: Macromol. Mater. Eng. 7/2006

Abstract

Cover: Spinnabilities of electrospun polystyrene nanofibers were quantified by the average value of the % coverages of fibers on the SEM micrographs to investigate the effect of solvent properties to fiber spinnability. The parameter G was modeled to represent the spinnability predicted by a force balance equation. Further details can be found in the article by C. Pattamaprom,* W. Hongrojjanawiwat, P. Koombhongse,* P. Supaphol, T. Jarusuwannapoo, and R. Rangkupan on page 840.

Electrospinning of poly(lactic acid): Theoretical approach for the solvent selection to produce defect‐free nanofibers

“…2,4,5 As a first step in choosing a suitable solvent system, the Flory-Huggins chi parameter (v) has been used to indicate the compatibility of solvent and polymer. 6,7 It uses the Hildebrand solubility parameter of solvent (d S ) and polymer (d P ), as shown in eq 1, 1,5,8,9 where M s is the molecular weight of the solvent (g/mol), R the universal gas constant (MPa cm 3 /K/mol), T the absolute temperature (K), and q s is the density of the solvent (g/cm 3 ), the value 0.34 represents a lattice parameter.…”

“…If v is lower than 0.5 then there are favorable solvent-polymer interactions, whereas if v is greater than 0.5 then polymer-polymer self-interactions are favored, and the polymer chain coils will contract. 1,8,10 The Flory-Huggins parameter is a good indicator of how strong are the interactions between polymer chains and the solvent molecules. However, it has been shown that this is not a general rule to predict polymer solubility since the secondary forces are not individually compared.…”

“…However, it has been shown that this is not a general rule to predict polymer solubility since the secondary forces are not individually compared. For example, Pattamaprom et al 8 dissolved poly styrene in dimethylformamide (DMF) and nitrobenzene at all concentrations (10%, 20%, and 30% w/v), despite the fact the v parameter was much higher than 0.5. Moreover the Flory-Huggins parameter is a temperature-dependent quantity and also concentration-dependent over a wide range of polymer concentration.…”

Micropatterning of Electrospun Polyurethane Fibers Through Control of Surface Topography

“…Thus, solvents with higher dipole moments are subject to greater electrical forces which impacts the ''electrospinnability'' of the polymer solution. [26] The comparisons between the PEsU fibers and the PEUU fibers seen in Figure 3 show a distinct difference in the effect of the patterned PDMS despite having the same conductive solvent, dimethylacetamide. Therefore, the difference in patterning was attributed to differences in contribution to the total dipole moment from the polymers themselves, specifically, the carbonyl of the ester linkages in the soft segment of the PEsU that are absent in the PEUU.…”

Development of molecularly imprinted polymeric nanofibers by electrospinning and applications to pesticide adsorption

“…It has been shown that electrospun PS fibers can be produced by using various solvent systems, and among these, DMF was found to be the most favorable solvent for producing uniform PS fibers. Compared to other solvents, such as tetrahydrofuran, ethyl acetate, and chloroform, DMF has a higher dipole moment and thus the highest spinnability for electrospinning [23]. Electrospinning was carried out on a self-made electrospinning machine.…”