Nano- and microemulsions containing as the oil phase caprylic/capric propylene glycol diesters (Crodamol PC) were investigated as potential vehicle for controlled release of geranic acid. The influence of emulsifiers and co-surfactants on stability of the emulsions was investigated. Different kind of polysorbates (ethoxylated esters of sorbitan and fatty acids) were applied as the emulsifiers. The short-chain alcohols (ethanol, 1-propanol, 1-butanol) were used as co-surfactants. The emulsions were prepared at ambient temperature (25°C), by the phase inversion composition method (PIC). The stable O/W high dispersed emulsion systems based on Crodamol PC, of mean droplets size less than 200 nm, were prepared. Microemulsions stabilized by the mixture of Polisorbat 80 and 1-butanol were characterized by the largest degree of dispersion (137 nm) and the lowest PDI value (0.094), at surfactant/co-surfactant: oil weight ratio 90:10. The stable nano-emulsion (mean droplet size of 33 nm) was obtained for surfactant: oil (S:O) weight ratio 90:10, without co-surfactant addition. This nano-emulsion was chosen to release studies. The obtained results showed that the prepared stable nano-emulsion can be used as a carrier for controlled release of geranic acid. The active substance release from the nano-emulsion and the oil solution, after 24 hours was 22%.
Abstract:The relaxation processes and the properties of polymer/ceramic nanocomposites have been studied by the 1 H nuclear magnetic resonance methods. Nanocomposites of poly(ethylene terephthalate) PET and poly(phenylene sulfide) PPS with 0.25, 2.5 and 5% wt. barium titanate BT were prepared using a twin screw extruder and injection moulding machine. The spin-lattice relaxation time T 1 , second moment M 2 and the motional parameters as e.g. the activation energies in the nanocomposites were investigated.
PACS
This paper concerns Single Minute Exchange of Die (SMED) which is one of lean tools applied for reduction of change over time on machines. It is a review paper on the basis of the literature collected from three electronic databases: Elsevier Science, Springer and E-resources from library of Poznan University of Technology. The retrieved articles were screened following the inclusion/exclusion criteria. After applying the literature selection criteria 40 articles published between the years 2000-2017 were chosen. These papers were classified on the basis of year of publication, journal title, main issue, tools and methods, type and also location. Their analysis revealed that SMED was applied in various range of enterprises in order to reduce time of setups and eliminate unnecessary activities which have no value for the process. It was also a useful tool for production process improvement as it may support lean tools in order to increase the process efficiency. The vast majority of papers was published in European countries. However, the increasing number of publications in recent years may suggest the increase of interest in this subject in different areas.
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