Ramon Rubio - Academia.edu (original) (raw)
Papers by Ramon Rubio
Polymers, Jul 12, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
![Research paper thumbnail of Influence of contact angle and temperature on evaporation of droplets [Abstract]](https://attachments.academia-assets.com/117480011/thumbnails/1.jpg)
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Springer eBooks, 2012
ABSTRACT The aim of present work is to describe results of computer simulations, which show the i... more ABSTRACT The aim of present work is to describe results of computer simulations, which show the influence of kinetic effects on evaporation of pinned sessile submicron droplets of water. The suggested model takes into account both diffusive and kinetic regimes of evaporation. The obtained results show a smooth transition between kinetic and diffusive regimes of evaporation as the droplet size decreases from millimetre to micrometer size.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, Nov 1, 2011
A theory is presented, which describes the diffusion limited evaporation of sessile water droplet... more A theory is presented, which describes the diffusion limited evaporation of sessile water droplets in presence of contact angle hysteresis. Theory describes two stages of evaporation process: (I) evaporation with a constant radius of the droplet base; and (II) evaporation with a constant contact angle. During stage (I) the contact angles decreases from static advancing contact angle to static receding contact angle. During stage (II) the contact angle remains equal to the static receding contact angle. Universal dependences are deduced for both evaporation stages. Obtained universal curves are validated against available in the literature experimental data.
Colloids and interfaces, Feb 16, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Colloids and Surfaces A: Physicochemical and Engineering Aspects, Aug 1, 2010
Advances in Colloid and Interface Science, Apr 1, 2014
Forests, 2021
Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative fo... more Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative formulations for wood protection against xylophagous fungi that are the main species responsible for different rots in wood structures. The dispersions as prepared and upon dilution (impregnation mixtures) were characterized by the apparent hydrodynamic diameter distribution of the oil droplets loaded with tebuconazole and their long-term stability. The impregnation mixtures were applied on wood of Populus canadensis I-214 clone by using a pressure-vacuum system, and the effectiveness against fungal degradation by Gloeophyllum sepiarium and Pycnoporus sanguineus fungi was determined. The retention of tebuconazole in wood was about 40% of the amount contained in the impregnation mixtures. The results showed that the impregnation process leads to a long-term antifungal protection to the wood, with the mass loss after 16 weeks being reduced more than 10 times in relation to the control (untre...
ACS Sustainable Chemistry & Engineering, 2020
Colloids and Interfaces, 2019
Essential oil compounds (EOCs) are molecules with well-known antimicrobial and antipest activity.... more Essential oil compounds (EOCs) are molecules with well-known antimicrobial and antipest activity. However, such molecules possess limited solubility in water, making their handling difficult. This work aimed to enhance the distribution of a solid essential oil compound, thymol, using oil-in-water (o/w) microemulsions for its solubilization. The use of mixtures formed by an alkyl polyglucoside (APG) and soybean lecithin (SL) allowed for stabilization of the o/w microemulsions in a broad range of compositions, with the total concentration of the mixture of the two surfactants (APG+SL) and the APG:SL ratio both being essential for controlling the nature of the obtained dispersions. The microemulsions obtained using oleic acid as the oil phase and with compositions far from those corresponding to the onset of the emulsion region showed a good efficiency for thymol solubilization. This is an advantage from a stability point of view, as well as for ease of thymol preparation. The present ...
Mathematical Modelling of Natural Phenomena, 2012
Journal of Colloid and Interface Science, 2013
Evaporation kinetics of sessile droplets of aqueous suspension of inorganic nanoparticles on soli... more Evaporation kinetics of sessile droplets of aqueous suspension of inorganic nanoparticles on solid substrates of various wettabilities is investigated from both experimental and theoretical points of view. Experimental results on evaporation of various kinds of inorganic nanosuspensions on solid surfaces of different hydrophobicities/hydrophilicities are compared with our theoretical predictions of diffusion limited evaporation of sessile droplets in the presence of contact angle hysteresis. The theory describes two main stages of evaporation process: (I) evaporation with a constant radius of the droplet base when the contact angle decreases from static advancing contact angle down to static receding contact angle and (II) evaporation with constant contact angle equal to the static receding contact angle when the radius of the droplet base decreases. Theoretically predicted universal dependences for both evaporation stages are compared with experimental data, and a very good agreement is found.
Dengue, Zika, chikungunya and yellow fever are the most important vector-borne diseases worldwide... more Dengue, Zika, chikungunya and yellow fever are the most important vector-borne diseases worldwide transmitted to humans by Aedes aegypti (L.) (Diptera Culicidae). Thus, the control of this vector is of vital importance in order to avoid epidemics in tropical and neo-tropical areas. To find new and effective larvicidal formulations for control programs against mosquito populations, aqueous dispersions containing thymol and eugenol were characterized and tested against Ae. aegypti larvae. The dispersion and stabilization of thymol and eugenol in water was possible using a triblock copolymer with two lateral blocks of poly(ethylene oxide) and a central block of poly(propylene oxide), the so-called poloxamer 407, which allows obtaining oil in water (o/w) emulsion. Dynamic Light Scattering (DLS) points out that emulsions containing eugenol were in most cases monodisperse with an average apparent hydrodynamic diameter of the droplets in the 20-25 nm without destabilization after 28 months...
Journal of Agricultural and Food Chemistry, 2021
The inherent thermodynamic instability of liposomes during production and storage has limited the... more The inherent thermodynamic instability of liposomes during production and storage has limited their widespread applications. Therefore, a novel structure of food-grade nanoliposomes stabilized by a 3D organogel network within the bilayer shell was developed through the extrusion process and successfully applied to encapsulate vitamin D 3. A huge flocculation and a significant reduction of zeta potential (−17 mV) were observed in control nanoliposomes (without the organogel shell) after 2 months of storage at 4°C, while the sample with a gelled bilayer showed excellent stability with a particle diameter of 105 nm and a high negative zeta potential (−63.4 mV), even after 3 months. The development of spherical vesicles was confirmed by TEM. Interestingly, the gelled bilayer shell led to improved stability against osmotically active divalent salt ions. Electron paramagnetic resonance confirmed the higher rigidity of the shell bilayer upon gelation. The novel liposome offered a dramatic increase in encapsulation efficiency and loading of vitamin D 3 compared to those of control.
Zenodo (CERN European Organization for Nuclear Research), Mar 25, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Coatings, 2019
The assembly in solution of the cationic polymer poly(diallyldimethylammonium chloride) (PDADMAC)... more The assembly in solution of the cationic polymer poly(diallyldimethylammonium chloride) (PDADMAC) and two different anionic surfactants, sodium lauryl ether sulfate (SLES) and sodium N-lauroyl-N-methyltaurate (SLMT), has been studied. Additionally, the adsorption of the formed complexes at the water–vapor interface have been measured to try to shed light on the complex physico-chemical behavior of these systems under conditions close to that used in commercial products. The results show that, independently of the type of surfactant, polyelectrolyte-surfactant interactions lead to the formation of kinetically trapped aggregates in solution. Such aggregates drive the solution to phase separation, even though the complexes should remain undercharged along the whole range of explored compositions. Despite the similarities in the bulk behavior, the equilibration of the interfacial layers formed upon adsorption of kinetically trapped aggregates at the water–vapor interface follows differe...
Polymers, 2021
The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials wi... more The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft collo...
Polymers, 2021
The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials wi... more The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft collo...
Polymers, Jul 12, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Springer eBooks, 2012
ABSTRACT The aim of present work is to describe results of computer simulations, which show the i... more ABSTRACT The aim of present work is to describe results of computer simulations, which show the influence of kinetic effects on evaporation of pinned sessile submicron droplets of water. The suggested model takes into account both diffusive and kinetic regimes of evaporation. The obtained results show a smooth transition between kinetic and diffusive regimes of evaporation as the droplet size decreases from millimetre to micrometer size.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, Nov 1, 2011
A theory is presented, which describes the diffusion limited evaporation of sessile water droplet... more A theory is presented, which describes the diffusion limited evaporation of sessile water droplets in presence of contact angle hysteresis. Theory describes two stages of evaporation process: (I) evaporation with a constant radius of the droplet base; and (II) evaporation with a constant contact angle. During stage (I) the contact angles decreases from static advancing contact angle to static receding contact angle. During stage (II) the contact angle remains equal to the static receding contact angle. Universal dependences are deduced for both evaporation stages. Obtained universal curves are validated against available in the literature experimental data.
Colloids and interfaces, Feb 16, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Colloids and Surfaces A: Physicochemical and Engineering Aspects, Aug 1, 2010
Advances in Colloid and Interface Science, Apr 1, 2014
Forests, 2021
Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative fo... more Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative formulations for wood protection against xylophagous fungi that are the main species responsible for different rots in wood structures. The dispersions as prepared and upon dilution (impregnation mixtures) were characterized by the apparent hydrodynamic diameter distribution of the oil droplets loaded with tebuconazole and their long-term stability. The impregnation mixtures were applied on wood of Populus canadensis I-214 clone by using a pressure-vacuum system, and the effectiveness against fungal degradation by Gloeophyllum sepiarium and Pycnoporus sanguineus fungi was determined. The retention of tebuconazole in wood was about 40% of the amount contained in the impregnation mixtures. The results showed that the impregnation process leads to a long-term antifungal protection to the wood, with the mass loss after 16 weeks being reduced more than 10 times in relation to the control (untre...
ACS Sustainable Chemistry & Engineering, 2020
Colloids and Interfaces, 2019
Essential oil compounds (EOCs) are molecules with well-known antimicrobial and antipest activity.... more Essential oil compounds (EOCs) are molecules with well-known antimicrobial and antipest activity. However, such molecules possess limited solubility in water, making their handling difficult. This work aimed to enhance the distribution of a solid essential oil compound, thymol, using oil-in-water (o/w) microemulsions for its solubilization. The use of mixtures formed by an alkyl polyglucoside (APG) and soybean lecithin (SL) allowed for stabilization of the o/w microemulsions in a broad range of compositions, with the total concentration of the mixture of the two surfactants (APG+SL) and the APG:SL ratio both being essential for controlling the nature of the obtained dispersions. The microemulsions obtained using oleic acid as the oil phase and with compositions far from those corresponding to the onset of the emulsion region showed a good efficiency for thymol solubilization. This is an advantage from a stability point of view, as well as for ease of thymol preparation. The present ...
Mathematical Modelling of Natural Phenomena, 2012
Journal of Colloid and Interface Science, 2013
Evaporation kinetics of sessile droplets of aqueous suspension of inorganic nanoparticles on soli... more Evaporation kinetics of sessile droplets of aqueous suspension of inorganic nanoparticles on solid substrates of various wettabilities is investigated from both experimental and theoretical points of view. Experimental results on evaporation of various kinds of inorganic nanosuspensions on solid surfaces of different hydrophobicities/hydrophilicities are compared with our theoretical predictions of diffusion limited evaporation of sessile droplets in the presence of contact angle hysteresis. The theory describes two main stages of evaporation process: (I) evaporation with a constant radius of the droplet base when the contact angle decreases from static advancing contact angle down to static receding contact angle and (II) evaporation with constant contact angle equal to the static receding contact angle when the radius of the droplet base decreases. Theoretically predicted universal dependences for both evaporation stages are compared with experimental data, and a very good agreement is found.
Dengue, Zika, chikungunya and yellow fever are the most important vector-borne diseases worldwide... more Dengue, Zika, chikungunya and yellow fever are the most important vector-borne diseases worldwide transmitted to humans by Aedes aegypti (L.) (Diptera Culicidae). Thus, the control of this vector is of vital importance in order to avoid epidemics in tropical and neo-tropical areas. To find new and effective larvicidal formulations for control programs against mosquito populations, aqueous dispersions containing thymol and eugenol were characterized and tested against Ae. aegypti larvae. The dispersion and stabilization of thymol and eugenol in water was possible using a triblock copolymer with two lateral blocks of poly(ethylene oxide) and a central block of poly(propylene oxide), the so-called poloxamer 407, which allows obtaining oil in water (o/w) emulsion. Dynamic Light Scattering (DLS) points out that emulsions containing eugenol were in most cases monodisperse with an average apparent hydrodynamic diameter of the droplets in the 20-25 nm without destabilization after 28 months...
Journal of Agricultural and Food Chemistry, 2021
The inherent thermodynamic instability of liposomes during production and storage has limited the... more The inherent thermodynamic instability of liposomes during production and storage has limited their widespread applications. Therefore, a novel structure of food-grade nanoliposomes stabilized by a 3D organogel network within the bilayer shell was developed through the extrusion process and successfully applied to encapsulate vitamin D 3. A huge flocculation and a significant reduction of zeta potential (−17 mV) were observed in control nanoliposomes (without the organogel shell) after 2 months of storage at 4°C, while the sample with a gelled bilayer showed excellent stability with a particle diameter of 105 nm and a high negative zeta potential (−63.4 mV), even after 3 months. The development of spherical vesicles was confirmed by TEM. Interestingly, the gelled bilayer shell led to improved stability against osmotically active divalent salt ions. Electron paramagnetic resonance confirmed the higher rigidity of the shell bilayer upon gelation. The novel liposome offered a dramatic increase in encapsulation efficiency and loading of vitamin D 3 compared to those of control.
Zenodo (CERN European Organization for Nuclear Research), Mar 25, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Coatings, 2019
The assembly in solution of the cationic polymer poly(diallyldimethylammonium chloride) (PDADMAC)... more The assembly in solution of the cationic polymer poly(diallyldimethylammonium chloride) (PDADMAC) and two different anionic surfactants, sodium lauryl ether sulfate (SLES) and sodium N-lauroyl-N-methyltaurate (SLMT), has been studied. Additionally, the adsorption of the formed complexes at the water–vapor interface have been measured to try to shed light on the complex physico-chemical behavior of these systems under conditions close to that used in commercial products. The results show that, independently of the type of surfactant, polyelectrolyte-surfactant interactions lead to the formation of kinetically trapped aggregates in solution. Such aggregates drive the solution to phase separation, even though the complexes should remain undercharged along the whole range of explored compositions. Despite the similarities in the bulk behavior, the equilibration of the interfacial layers formed upon adsorption of kinetically trapped aggregates at the water–vapor interface follows differe...
Polymers, 2021
The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials wi... more The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft collo...
Polymers, 2021
The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials wi... more The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft collo...
Langmuir, 2012
In this work, we study how structures develop on 2D dense binary colloidal monolayers as a functi... more In this work, we study how structures develop on 2D dense binary colloidal monolayers as a function of the relative concentration of small/large particles. Translational and orientational distribution functions have been used to monitor the continuous phase transition through a detailed characterization of the global and local order. We have observed how a gradual enhancement in the number of particles of different sizes leads to a continuous vitrification process and how homogeneous binary glasses form in equimolar mixtures. Also, we have performed a simple calculation that relates the structures found to the pair dipolar potential, allowing the forecast of local structures in other arbitrary binary mixtures. Finally, we have corroborated the goodness of the binary systems as a glass-forming model by comparing the established scenario with the structural features found in partially aggregated monolayers.