Grupo: Física de fluidos y biocoloides (FQM115)https://hdl.handle.net/10481/146402024-03-29T11:21:40Z2024-03-29T11:21:40ZWater-Repellent Fluoropolymer-Based CoatingsPaz-Gómez, GuillermoCabrerizo Vílchez, Miguel ÁngelRodríguez Valverde, Miguel Ángelhttps://hdl.handle.net/10481/620052021-06-15T13:18:59ZWater-Repellent Fluoropolymer-Based Coatings
Paz-Gómez, Guillermo; Cabrerizo Vílchez, Miguel Ángel; Rodríguez Valverde, Miguel Ángel
Fluoropolymer-based coatings are widely used for release applications. However, these hydrophobic surfaces do not reveal a significantly low adhesion. Water repellency incorporated to fluoropolymer coatings might enhance their release performance. In this work, we focused on the surface texturing of a well-known polytetrafluoroethylene (PTFE)-based coating. We explored as texturing routes: sanding, sandblasting and laser ablation. We examined the surface roughness with white light confocal microscopy and the surface morphology with environmental scanning electron microscopy (ESEM). Water-repellent fluoropolymer coatings were reproduced in all cases, although with different degree, parametrized with bounces of water drops (4–5 μL). Laser ablation enabled the lowest adhesion of coatings with 24 ± 2 bounces. This result and the current development of laser patterning for industry assure the incipient use of laser ablation for release coatings.
We would like to thank to the company TECNIMACOR S.L. (Córdoba, Spain) for the preparation of the coatings studied in this work.
Tribological Behavior of Glycerol/Water-Based Magnetorheological Fluids in PMMA Point ContactsRosa, Wagner O.Vereda Moratilla, FernandoVicente Álvarez-Manzaneda, Juan Dehttps://hdl.handle.net/10481/618582022-05-16T07:11:44ZTribological Behavior of Glycerol/Water-Based Magnetorheological Fluids in PMMA Point Contacts
Rosa, Wagner O.; Vereda Moratilla, Fernando; Vicente Álvarez-Manzaneda, Juan De
Comprehension of the tribological behavior of magnetorheological fluids is crucial for many applications, in particular for those related with high quality surface finishing. In this contribution, we describe a thorough experimental investigation on the tribological properties of magnetorheological (MR) fluids in poly(methyl methacrylate) (PMMA) point contacts. First, magnetic iron oxide particles with diameters of ~0.4, 1,3, and 2.0 μm were prepared using wet chemistry procedures. Then, MR fluids were formulated by dispersion of the magnetic particles in glycerol/water mixtures. The tribological experiments were run in a PMMA ball-on-three plates tribometer and Stribeck regions were identified for a wide range of sliding speeds. The wear tracks were also visualized in a confocal microscope to correlate them with friction coefficient data. The results show the effect of both particle size and applied magnetic field in the friction coefficient and wear scar volume, suggesting a slight decrease on the wear process when the magnetic field is present.
Formulation, Colloidal Characterization, and In Vitro Biological Effect of BMP-2 Loaded PLGA Nanoparticles for Bone RegenerationCastillo Santaella, Teresa delOrtega-Oller, InmaculadaPadial Molina, MiguelO'Valle Ravassa, Francisco JavierGalindo Moreno, Pablo AntonioJódar Reyes, Ana BelénPeula-García, José Manuelhttps://hdl.handle.net/10481/615042021-10-26T07:23:54ZFormulation, Colloidal Characterization, and In Vitro Biological Effect of BMP-2 Loaded PLGA Nanoparticles for Bone Regeneration
Castillo Santaella, Teresa del; Ortega-Oller, Inmaculada; Padial Molina, Miguel; O'Valle Ravassa, Francisco Javier; Galindo Moreno, Pablo Antonio; Jódar Reyes, Ana Belén; Peula-García, José Manuel
Nanoparticles (NPs) based on the polymer poly (lactide-co-glycolide) acid (PLGA) have been widely studied in developing delivery systems for drugs and therapeutic biomolecules, due to the biocompatible and biodegradable properties of the PLGA. In this work, a synthesis method for bone morphogenetic protein (BMP-2)-loaded PLGA NPs was developed and optimized, in order to carry out and control the release of BMP-2, based on the double-emulsion (water/oil/water, W/O/W) solvent evaporation technique. The polymeric surfactant Pluronic F68 was used in the synthesis procedure, as it is known to have an effect on the reduction of the size of the NPs, the enhancement of their stability, and the protection of the encapsulated biomolecule. Spherical solid polymeric NPs were synthesized, showing a reproducible multimodal size distribution, with diameters between 100 and 500 nm. This size range appears to allow the protein to act on the cell surface and at the cytoplasm level. The effect of carrying BMP-2 co-adsorbed with bovine serum albumin on the NP surface was analyzed. The colloidal properties of these systems (morphology by SEM, hydrodynamic size, electrophoretic mobility, temporal stability, protein encapsulation, and short-term release profile) were studied. The effect of both BMP2-loaded NPs on the proliferation, migration, and osteogenic differentiation of mesenchymal stromal cells from human alveolar bone (ABSC) was also analyzed in vitro.
The following are available online at https://www.mdpi.com/1999-4923/11/8/388/s1, Figure S1. Scheme of the formulation of NP-BMP2; Figure S2: Scheme of the protein adsorption process for NP-BSA-BMP2; Video S1. NTA experiments for NP-BMP2; Video S2. NTA experiments for empty NPs.
Non-Stick Coatings in Aluminium Molds for the Production of Polyurethane FoamSánchez-Urbano, FranciscoPaz-Gómez, GuillermoRodríguez-Alabanda, ÓscarRomero, Pablo E.Cabrerizo Vílchez, Miguel ÁngelRodríguez Valverde, Miguel ÁngelGuerrero Vaca, Guillermo Rafaelhttps://hdl.handle.net/10481/555962021-06-15T13:19:00ZNon-Stick Coatings in Aluminium Molds for the Production of Polyurethane Foam
Sánchez-Urbano, Francisco; Paz-Gómez, Guillermo; Rodríguez-Alabanda, Óscar; Romero, Pablo E.; Cabrerizo Vílchez, Miguel Ángel; Rodríguez Valverde, Miguel Ángel; Guerrero Vaca, Guillermo Rafael
The manufacturing of polyurethane foam is a process of great industrial importance in the
automotive and furniture sector. The operation of demolding is the most delicate, since the foam
sticks firmly to the walls of the mold onto which it has spread. In order to avoid the use of demolding
agents, the proposal is to coat the inside of the molds with non-stick coatings. In this work, three types
of different coatings were studied: fluoropolymers, ceramics, and elastomers. After carrying out
different tests in the laboratory, two fluoropolymer coatings (PFA (perfluoroalkoxy) and PTFE
(polytetrafluoroethylene)) were selected for a test at the industrial level and, after 1500 cycles
of demolding, it was experimentally proven that the PFA coating is the most adequate for the
use studied.
Adsorption of Milk Proteins (β-Casein and β-Lactoglobulin) and BSA onto Hydrophobic SurfacesPérez Fuentes, LeonorDrummond, CarlosFaraudo Gener, JordiBastos González, Delfina Maríahttps://hdl.handle.net/10481/475592024-01-08T08:42:45ZAdsorption of Milk Proteins (β-Casein and β-Lactoglobulin) and BSA onto Hydrophobic Surfaces
Pérez Fuentes, Leonor; Drummond, Carlos; Faraudo Gener, Jordi; Bastos González, Delfina María
Here, we study films of proteins over planar surfaces and protein-coated microspheres obtained from the adsorption of three different proteins ( β -casein, β -lactoglobulin and bovine serum albumin (BSA)). The investigation of protein films in planar surfaces is performed by combining quartz crystal microbalance (QCM) and atomic force microscopy (AFM) measurements with all-atomic molecular dynamics (MD) simulations. We found that BSA and β -lactoglobulin form compact monolayers, almost without interstices between the proteins. However, β -casein adsorbs forming multilayers. The study of the electrokinetic mobility of protein-coated latex microspheres shows substantial condensation of ions from the buffer over the complexes, as predicted from ion condensation theories. The electrokinetic behavior of the latex-protein complexes is dominated by the charge of the proteins and the phenomenon of ion condensation, whereas the charge of the latex colloids plays only a minor role.