The List of recent finished Projects, financed by Slovenian Research Agency (ARRS):
- »Electrospun nanofibrous materials for solid state drug delivery system« (1.3.2016-28-02-2019), Project Head: prof. dr. Igor Emri
The project addresses establishment of electrospinning needle-free technology of biocompatible bimodal polyamide 6 that will be used for manufacturing containers for Solid State Drug Delivery approach. This approach utilizes polymeric electrospun nanofibrous materials as a shell material for drug carrier containers for targeted chemotherapy of localized tumors and prolonged drug release needed in case of chronic diseases. Possibility to control drug release rate is a crucial factor of the proposed approach and can be achieved via changes of pore size distribution of the membrane and degradability rate of a polymer.
Biodegradability rate as well as its effect on pore size distribution PSD depends on chemical composition of the polymer and its structure. Patented biocompatible multimodal polyamide 6 is chosen for this project because of its outstanding biocompatibility and extremely high sensitivity to strain-rate, temperature and pressure variation during the production process. These properties allow forming gradient structure of a solid material using injection-molding technique, as well as gradient nano-fibers manufactured with electrospinning process. In this case strain-rate of the pulling of polymer solution by electrostatic field will result in different fiber structure, which will directly influence the rate of biodegradability.
Pore size distribution (PSD) depends only on the technological process of electrospinning, which establishment is the goal of the proposed project. PSD depends on fiber diameter, and membrane thickness, which in turn are determined by parameters of manufacturing process (solution composition, air conditioning,…).
In line with this, the goal of the proposed project is to determine interrelation between fiber diameter and membrane thickness that affect pore size and pore size distribution, and electrospinning processing parameters for multimodal polyamide 6. Investigation of the solution composition, its viscosity, electrical conductivity and surface tension properties, effect of electrostatic field on the electrospinning process, quality and diameter of the formed fibers will be performed. In addition structural analysis of the fibers will be done. Materials with different pore size distributions, in order to study effect of membrane thickness and fiber diameter, will be manufactured and their pore size distribution will be measured and confirmed by the diffusion tests on model drugs.
- »Improvement of flowability and density of feedstock used in nanoPowder Injection Moulding (nanoPIM)« (1.7.204-30.6.2017), Project Head: prof. dr. Igor Emri
This project addresses the key problem of the new nano-powder injection molding technology (nPIM), which is an evolutionary however substantial improvement of the existing PIM technology, and may be considered as one of the ultimate future emerging technologies (FET) for manufacturing metallic and/or ceramic structural elements with complex geometry. The key advantages of parts made with nPIM in comparison with those made with PIM technology are their superior mechanical properties (in particular fatigue resistance), and their surface quality that reaches the grade of “polished surface”. The key problem of nPIM is extremely high processing pressures (several MPa) resulting from poor flowability of polymer-metal and polymer-ceramics mixtures at elevated pressure. Solution of this problem is the ultimate goal of this project.
Nano-powder injection molding (nPIM) is a versatile technology for manufacturing small parts with complex geometry made out of metal or ceramic. nPIM relies on the preparation of a composite material consisting of a polymer matrix and metal or ceramic powders, commonly called feedstock. Automotive, electronics and medical industries could greatly benefit from utilizing nPIM. However there are several factors that affect the widespread of nPIM technology. One of them is the long time required to remove the polymeric matrix material used during molding. This issue has been partially solved by using polymers that undergo fast degradation (e.g. polyoxymethylene – POM) under the appropriate conditions, but new limitations have risen since such polymers have very high viscosity, which requires extremely high pressures during the molding step.
The goal of this project is to find ultimate “composition” of the feedstock based on POM. In line with this goal this project aims to reduce the viscosity of the feedstock material used in PIM and nPIM while maintaining good mechanical properties in solid state. This will be achieved by (i) manipulating the molecular mass distribution of the polymeric matrix material, and by (ii) selecting the appropriate particle size distribution of the filler powders, which will include nano and micro particles. Special attention will be given to (iii) the effect of temperature and pressure on the improved feedstock material, needed for the optimization of the processing parameters. Finally, (iv) the performance of the improved feedstock will be demonstrated by carrying out the complete PIM process and manufacture test parts with complex geometry.
The List of Past Projects, financed by the Slovenian Research Agency ARRS):
– Behavior of dissipative systems under extreme thermo-mechanical loading (1.7.2011―30.6.2014)
– Vibroacoustic construction elements based on waste tires (1.5.2009―30.4.2012)
– Nanostructured polymeric implants in medicine (1.2.2008―30.1.2011)
Intelligent protecting composite plates and shells (1.6.2006―30.11.2007)
– Development of the new cardiovascular surgical technique utilizing the intelligent PA materials (1.7.2004―30.6.2007)
– The development of protective and safety equipment for the modern soldier using nanostructured polymeric materials (1.8.2004―31.8.2006)
– Intelligent fibers for medical applications (1.1.2003―31.12.2005)
– Research on thermo-mechanical properties of commutators (1.7.1998―30.6.2001)
– Characterization and behavior of viscoelastic materials (1.7.1997―30.6.2000)