ESR03 - Pedro Jesus Navarrete Segado

Background:

Pedro started the degree of Chemistry (4 years) in 2011 in the University of Jaén and completed it successfully, obtaining a special distinction in his bachelor's thesis on the "Synthesis of bolaamphiphiles with aromatic core and their interactions with graphene-like systems" under the personal supervision of Dr. Manuel Melguizo Guijarro. During his bachelor’s degree, he acquired a vast theoretical background in chemistry and good laboratory skills, it was then when his interest in research awoke.

The following year after finishing, he worked as a trainee in the R&D department of ANDALTEC foundation, an important technological centre for the polymer and nanotechnology sector in Jaén during 9 months, where he has been author of a patent in a project about the development of self-healing thermoplastic nanocomposites. He was working everyday hand-in-hand with a multidisciplinary team of engineers, designers, and technicians.

At the end of 2016, he started a master’s degree in nanostructured materials for nanotechnology applications in the University of Zaragoza where he was specializing in the field of nanotechnology, learning about a multitude of techniques devoted to the characterization and preparation on nanomaterials. His master's thesis was based on the "Preparation and characterization of nanostructures based on bent-core molecules onto graphene” under the supervision of Dr. Santiago Martín Solans and the professor M. Blanca Ros.

In 2017, he was recipient of a European grant, Vulcanus in Japan (EU-Japan Center) which consisted on a 1-year stay in Japan for a 4-month intensive Japanese language and culture course at The Naganuma School and 8-month industrial placement at Hitachi, Ltd. - Central Research Laboratory where he was developing new technologies related to scanning probe microscopy.

From 2018, he is part of the Marie-Curie project “DOC-3D-PRINTING” in the National Polytechnic Institute of Toulouse as Early-Stage Researcher Fellow. He is currently developing the additive manufacturing processing of bioceramics with “Tailoring calcium phosphate powder properties for 3D-laser printing” as the subject of his doctoral thesis.

Presentation of the individual project:

Orthopedic joint replacement, prosthesis, and dental restoration by means of bioceramic materials has been investigated since the 1960s; its interest is due to the many advantages compared to other materials. In combination with additive manufacturing technologies, bioceramics parts can be designed with complex shapes to be harder and stiffer than steel with better thermal and chemical resistance than metals or polymers, and at the same time to be biocompatible and/or bioactive improving the osseointegration/osseoincorporation of the implants.

Due to their strong similarities with the natural mineral component, calcium phosphates ceramics (stoichiometric hydroxyapatite, B-TCP, substituted calcium phosphates, and biphasic compounds) are privileged biomaterials as orthopaedic implants or dental restorations in medical or aesthetics applications. Selective Laser Melting/Sintering are promising additive manufacturing techniques allowing the production of functional complex net-shaped and fully dense parts. However, specific tailored powder for these 3D-laser printing techniques need to be produced.

The challenge here is to produce nano-structured agglomerates in order to increase the surface and thus the reactivity required for effective sintering (submicronic particles) while keeping suitable flowability and dispersing properties for handling facilities, which is preferably achieved by spherical agglomerated particles of a few tens of microns. Within this context, the objectives of the phD work will be to understand the relationships between the powder properties and the synthesis process parameters. The tailored nano-structured agglomerates could be produced through a multistep process based on precipitation, wet nanogrinding, calcination and spray-drying steps, arranged in this order or differently. The effect of the operational parameters on the chemical and physical properties of the powder will be characterized as well as their sinterability (by additive technologies and conventional sintering).