Naroa Sadaba - Academia.edu (original) (raw)

Papers by Naroa Sadaba

Frontiers in Bioengineering and Biotechnology, 2016

Advanced Materials Technologies

Stretchable conductive materials have attracted great attention due to their potential applicatio... more Stretchable conductive materials have attracted great attention due to their potential applications as strain sensors, wearable electronics, soft robotics, and medical devices. The fabrication of these materials with customized object geometries is desirable, but the methods to achieve them are still highly limited. Additive manufacturing via vat photopolymerization can generate sophisticated object geometries, but there is still a significant need to print with materials that afford improved conductivity, mechanical properties, elastic recovery, and durability. Herein, stretchable strain sensors with a range of 3D printed designs are reported using vat photopolymerization. Ionic liquid resins are optimized for their printability using Sudan‐I as a photoabsorber and used to fabricate 3D objects that are subjected to compression, stretching, and bending loads that are detected as real‐time changes in current. Additionally, the self‐adhesive nature of these materials enables mechanica...

Express Polymer Letters, 2018

Random poly (vinyl chloride-co-butyl acrylate) and poly (vinyl chloride-co-2-ethylhexyl acrylate ... more Random poly (vinyl chloride-co-butyl acrylate) and poly (vinyl chloride-co-2-ethylhexyl acrylate copolymers obtained by single electron transfer-degenerative chain transfer living radical polymerization (SET-DTLRP) are investigated as potential candidates for 3D Printing. The analysis of the rheological implications of 3D Printing process allows establishing the basic viscoelastic conditions that the samples should fulfil to be printable, avoiding the 'trial and error' procedure. The effect of temperature and acrylates concentration on the rheological properties and 3D printing feasibility is contemplated. Eventually, thermal degradation is also considered. It is demonstrated that the copolymers which contain butyl acrylate comonomer, instead of 2-ethylhexyl acrylate, give raise to the best results. Although the study is carried out with PVCacrylate copolymers and a 3D printing device that possesses set up characteristics, it shows a way to work out sound strategies with other polymers and 3D printing machines.

Polymer Testing, 2018

Understanding the toughness mechanism prompted by submicron rigid particles in polylactide/barium... more Understanding the toughness mechanism prompted by submicron rigid particles in polylactide/barium sulfate composites,

European Polymer Journal, 2015

Abstract In the present work, incorporation of submicron barium sulphate (BaSO 4 ) particles to a... more Abstract In the present work, incorporation of submicron barium sulphate (BaSO 4 ) particles to a poly( l -lactide) (PLLA) matrix is explored as a strategy to improve the radiopacity and simultaneously enhance the toughness of the resulting composites. Accordingly, BaSO 4 loaded PLLA composites were prepared via melt-blending and were fully characterized in terms of thermal transitions, mechanical properties, morphology and radiopacity. X-ray analysis confirmed the enhanced radiopacity of the BaSO 4 filled composites with respect to their unfilled counterparts. Additionally, toughness of PLLA matrix was impressively improved when BaSO 4 particles were added. As an illustration, incorporation of 10 wt.% of BaSO 4 particles resulted in a 1647 and 3338% increase in toughness and elongation of PLLA matrix, respectively.

International Journal of Molecular Sciences, 2020

This work reports the versatility of polydopamine (PD) when applied as a particle coating in a co... more This work reports the versatility of polydopamine (PD) when applied as a particle coating in a composite of polylactide (PLA). Polydopamine was observed to increase the particle–matrix interface strength and facilitate the adsorption of drugs to the material surface. Here, barium sulfate radiopaque particles were functionalized with polydopamine and integrated into a polylactide matrix, leading to the formulation of a biodegradable and X-ray opaque material with enhanced mechanical properties. Polydopamine functionalized barium sulfate particles also facilitated the adsorption and release of the antibiotic levofloxacin. Analysis of the antibacterial capacity of these composites and the metabolic activity and proliferation of human dermal fibroblasts in vitro demonstrated that these materials are non-cytotoxic and can be 3D printed to formulate complex biocompatible materials for bone fixation devices.

Macromolecules, 2020

Photopolymerization is a powerful tool in materials science with many applications, including coa... more Photopolymerization is a powerful tool in materials science with many applications, including coatings, adhesives, inks, and 3D printing. Until now, the majority of photoinitiating systems have bee...

Polymers, 2018

There is a great interest in incorporating catechol moieties into polymers in a controlled manner... more There is a great interest in incorporating catechol moieties into polymers in a controlled manner due to their interesting properties, such as the promotion of adhesion, redox activity or bioactivity. One possibility is to incorporate the catechol as end-group in a polymer chain using a functional initiator by means of controlled polymerization strategies. Nevertheless, the instability of catechol moieties under oxygen and basic pH requires tedious protection and deprotection steps to perform the polymerization in a controlled fashion. In the present work, we explore the organocatalyzed synthesis of catechol end-functional, semi-telechelic polylactide (PLLA) using non-protected dopamine, catechol molecule containing a primary amine, as initiator. NMR and SEC-IR results showed that in the presence of a weak organic base such as triethylamine, the ring-opening polymerization (ROP) of lactide takes place in a controlled manner without need of protecting the cathechol units. To further confirm the end-group fidelity the catechol containing PLLA was characterized by Cyclic Voltammetry and MALDI-TOF confirming the absence of side reaction during the polymerization. In order to exploit the potential of catechol moieties, catechol end-group of PLLA was oxidized to quinone and further reacted with aliphatic amines. In addition, we also confirmed the ability of catechol functionalized PLLA to reduce metal ions to metal nanoparticles to obtain well distributed silver nanoparticles. It is expected that this new route of preparing catechol-PLLA polymers without protection will increase the accessibility of catechol containing biodegradable polymers by ROP.

ACS Applied Polymer Materials, 2020

Herein, we demonstrate 3D printing of an elastomeric imidazolium polyamide-ionene which exhibits ... more Herein, we demonstrate 3D printing of an elastomeric imidazolium polyamide-ionene which exhibits intrinsic shape-memory (SM) and self-healing (SH) character, reporting optimized printing conditions...

The use of three-dimensional (3D) printable hydrogels for biomedical applications has attracted c... more The use of three-dimensional (3D) printable hydrogels for biomedical applications has attracted considerable attention as a consequence of the ability to precisely define the morphology of the printed object, allowing patients' needs to be targeted. However, the majority of hydrogels do not possess suitable mechanical properties to fulfill an adequate rheological profile for printability, and hence, 3D printing of cross-linked networks is challenging and normally requires postprinting modifications to obtain the desired scaffolds. In this work, we took advantage of the crystallization process of poly(ethylene glycol) to print non-isocyanate poly(hydroxyurethane) hydrogels with tunable mechanical properties. As a consequence of the crystallization process, the hydrogel modulus can be tuned up to 3 orders of magnitude upon heating up to 40°C, offering an interesting strategy to directly 3D-print hydrogels without the need of postprinting cross-linking. Moreover, the absence of any toxicity makes these materials ideal candidates for biomedical applications.