31^st Materials Science and Engineering Conference: Advancement & Innovations October 15-17, 2018 Helsinki, Finland

Carolina Clausell Terol has completed her PhD in Chemical Engineer in 2008 and MSc in Chemical Engineer in 1998, both from Jaume I University. She is the Member of the Ceramic Technology research group since 1997 and since 2012, teaching and research staff at the Chemical Engineering Department of the same university. Her research career is focused in the application of the chemical engineering principles to the ceramic materials production processes, which she develops at the research group and the department that she belongs to. Furthermore, she is a Member of the collaborating research group chemistry of electromagnetic radiation processed materials between the Jaume I University and the Spanish National Research Council (CSIC), through the Aragón Materials Science Institute (ICMA). She has collaborated in 38 research projects, funded by public institutions and private companies, resulting in 2 patents, numerous scientific articles in international journals of the ceramic materials field indexed in the journal citation report and several contributions to national and international conferences of the same research field.

Cu-doped NiZn ferrites are typical electromagnetic wave absorbers which absorption capacity (calculated from experimental measures of complex permeability and complex permittivity for a given frequency range) is related to thickness body and especially and more critical to its microstructure. Ideal microstructure would consist of sintered bodies with no porosity, small average grain size and narrow grain size distribution. Moreover, the finer grain sizes the better absorption capacity. Literature shows that physical properties of ceramic bodies improve when particle-size distribution decreases from the micro-scale to the nanoscale. Ferrites from nanoparticles have been sintered controlling average grain size and relative density with sintering temperature. Green microstructure has been set constant using uniaxial dry pressing at 200 MPa as the shaping method. Sintered microstructure has been observed by Scanning Electron Microscopy (SEM), obtaining the average grain size by image analysis of the SEM micrographs. Relative density was determined by the Archimedes method, using true density material value. Magnetic permeability was measured in the frequency range from 1 MHz to 3 GHz by using an Agilent model E4991 ARF impedance analyzer with the 16454A test fixture and this later parameter has been related to average grain size and relative density. Finally, the results obtained from nano-particulate ferrite powder have been compared with those previously obtained from micro-particulate ferrite powders, noting an improvement in performance.

Rosalinda Caringella has been graduated in Chemistry from the University of Turin in 2012. Since 2014, she has been working as a Temporary Research Assistant at the Institute for Macromolecular Studies (ISMAC) of the Italian National Research Council (CNR). She has worked on the functionalization of natural fibers, preparation of bio-composites and valorization of wool wastes and extraction of keratin for biomedical, textile and pharmaceutical applications.

In this research work novel, polymeric composites reinforced with functionalized natural fibers have been produced, in order to replace fiberglass reinforcement in shipbuilding industry. The substitution of glass fibers with ligno-cellulosic fibers brings advantages also in terms of weight of the composites which results lighter than fiberglass ones, moreover it solves the issues linked to the complexity of the disposal procedure and the health risk of fiberglass composites. Different types of technical flax fabrics and felts, having different weight and fibers orientation were used as reinforcement after functionalization by polypyrrole, a conductive organic polymer which confers antistatic and EMI shielding properties, bacterial resistance and good compatibility with non-polar polymeric matrices. Polypyrrole functionalization was carried out by in situ polymerization of pyrrole monomer, using ammonium persulfate as the oxidant. The fabrics were dipped in pyrrole and oxidant solutions for 2 hours under mechanical stirring then a polyester resin commonly used in shipbuilding industry was applied on treated fabrics to produce the composites. The composites were characterized for surface functionalization, morphology, thermal and mechanical behaviour in order to establish their applicability in shipbuilding industry. Chemico-physical characterization showed that polypyrrole functionalization not affected the compatibility between fabrics and polyester resin. The novel composites exhibit the lowest tenacity and elastic modulus than fiberglass but showed comparable specific module, considering the specific density of the materials. Thermal analysis showed that functionalized fabrics degraded at slightly lower temperature but with lower heat release rate of the degradation process. The shift of the degradation temperature resulted more evident with the increase of the amount of polypyrrole on fabrics surface. Moreover, the composites reinforced with flax fabrics showed a significant reduction of the carbon residue which can be traduced into an advantage in terms of disposal by incineration and solves the problem of glass fibers dispersion.

Meral Karakisla Sahin is a Professor in the Department of Chemistry, Faculty of Science, Ankara University since 2009. She has her expertise in the area of conducting polymer composites, the synthesis of conducting polymers and applications, the preparation of graft copolymers, the synthesis of Schiff base polymers, the preparation of composite by improving their conductivity of textile and clay materials by using conducting polymers. In addition, she has made studies on the investigation of antibacterial and catalytic properties after deposition of silver nanoparticles to these composites and to prepare shielding material against to electromagnetic waves.

Polyacrylonitrile (PAN) fiber is used in the textile industry frequently and has a prominent place among the synthetic fibers. It has good thermal stability, compatibility with polar materials due to containing the high polar nitrile groups, hardness and high abrasion resistance. However, in spite of many superior properties of PAN fibers, some of their poor features such as low moisture absorption and poor antistatic properties limit their further usage. So, surface modification is particularly important for fiber/fabric materials and in order to modify the surface of PAN fiber, functional monomers can be incorporated into fiber structure. One of the most used methods for this purpose, the graft copolymerization method was used to graft Hydroxyethyl Methacrylate (HEMA) onto PAN fiber directly to get the surface modified fibers. The grafting processes were carried out in the aqueous medium containing benzoyl peroxide solution in acetone as initiator and HEMA solution at suitable concentrations. PAN fibers grafted HEMA at different percentages was prepared to depend on the polymerization conditions such as initiator and monomer concentration, polymerization temperature. Grafting yield was determined gravimetrically and the maximum grafting yield was obtained as about 90% under the conditions investigated. The chemical structure of PAN fiber-g-poly (hydroxyethyl methacrylate) was characterized by FTIR and H-NMR spectroscopic techniques. The surface morphology of the grafted fiber was studied by SEM.

Cyanoacrylate (CA) polymerization is normally triggered by traces of basic substances at the adhesive/substrate interface resulting in rapid formation of large molecular weight polymers. However there are some disadvantages, for instance, increasing the bond gap from 10 microns (zero gap bonds) to 100 microns can increase bond fixture time from a few seconds up to several minutes, sometimes limiting their service capabilities. The aim of this work is to use Raman spectroscopy and other surface analytical and chemical laboratory techniques to gain the improved understanding of the processes responsible for performance limitations of such adhesives. Raman will be employed to provide insights into the rates and mechanisms of the interfacial CA polymerization process, which are known to be independent of bulk polymerization processes. In addition, the examination of the timedependent and spatial behaviour of EIS data in conjunction with a mathematical model based on the diffusion of monomeric and/or polymeric species through the adhesive volume will aid our understanding of the polymerization processes occurring in various regions of the adhesive bond including the edge and the bulk material. By studying the effects of chemical and physical variations the fundamental questions regarding the degradation of adhesive joints by environmental stress will be addressed thereby enhancing our knowledge of the hydrolytic stability of CA adhesive bond.

Porous Si₃N₄ bodies are of interest in various applications including bio and aerospace. Silicon nitride bodies were prepared with porosity and flexural strength of about 38% and near 180 MPa, respectively. The processing was via gel-casting method employing acrylamide (AM) and N,N'−methylene bisacrylamide (MBAM) for primary slurry, followed by coke bed sintering. The concentrations of APS and TEMED as initiator and catalyst, the sintering time and temperature were studied and optimized. Phase evolution and microstructure observation, as well as flexural strength and porosity of porous Si₃N₄ bodies, were investigated. It was found above, sintering process at 1650 °C with prolonged time had a significant effect on strength in a way that bodies with 33% porosity could experience 250 MPa. Development of the interlocking microstructure of fine β-Si₃N₄ grains was found to be the key factor for the increase of strength. Controlling the primary slurry components was also vital for maintaining the high strength. The results were explained with emphasis on potential applications.