To obtain the best conditions for producing uniform nanofibers we tested the PHB and PHB-HV samples using several PHB concentrations and different capillary diameters, flow rates, voltages, and capillary to collect distances.
Flow rate, applied electric field, collecting distance and composition of the starting solutions determined the morphology of the obtained fibres.
Furthermore, the effect of electrospinning parameters, such as solution concentration, applied voltage, collecting distance, and rate of spinning, on the fiber dimensions and morphology are studied.
Smallest size was found to be obtained at minimum value for both flow rate and concentration of polymer, regardless of collecting distance value in the ranges studied.
Specifically, relative humidity (RH), temperature, collecting distance, feeding rate, and applied voltage were kept at 60%%, 22 °C, 15 cm, 1.5 ml/h, and 12 kV, respectively.
In total, a sample with minimum size and polydispersity was predicted to have flow rate, polymer concentration and collecting distance values of 0.06 (ml/h), 0.5 (%w/w) and 9.28 (cm), respectively.
Apart from that, 10% (w/v) PS solution (THF/DMF ratio, 1 1 v/v) was used as a model to check the effect of other parameters (e.g., relative humidity, applied voltage, collecting distance, feeding rate).
Overall, applied voltage, collecting distance, and feeding rate had little effect on the secondary morphology and fiber diameter, but relative humidity exerted great influence on diameter of grooved PS nanofibers.
Imani Development Consultants (2004) reported that, circa 2003, processors paid the milk bulking groups around 20 to 22 MK per litre but they noted that the price varied according to such factors as the volume collected, distance to the factory and a bonus system for the milk bulking groups etc.
Since this game is primarily a game of collecting distance – it is safe to say that it does not have an ending.
