Gloria Víllora

By Mercedes G. Montalbán, Mar Collado-González, F. Guillermo Díaz- Baños and Gloria Víllora

The determination of the physicochemical properties of ionic liquids (ILs), such as density and refractive index, is essential for the design of processes that involve ILs. Density has been widely studied in ILs because of its importance whereas refractive index has received less attention even though its determination is rapid, highly accurate and needs a small amount of sample in most techniques. Due to the large number of possible cation and anion combinations, it is not practical to use trial and error methods to find a suitable ionic liquid for a given function. It would be preferable to predict physical properties of ILs from their structure. We compile in this work different methods to predict density and refractive index of ILs from literature. Especially, we describe the method developed by the authors in a previous work for predicting density of ILs through their molecular volume. We also correlate our experimental measurements of density and refractive index of ILs in order to predict one of the parameters knowing the other one as a function of temperature. As the measurement of refractive index is very fast and needs only a drop of the ionic liquid, this is also a very useful approach.

Part of the book: Ionic Liquids

By Mercedes G. Montalbán, Guzmán Carissimi, A. Abel Lozano-Pérez, José Luis Cenis, Jeannine M. Coburn, David L. Kaplan and Gloria Víllora

Recently, much research has focused on the use of biopolymers, which are regarded as biodegradable, natural, and environmentally friendly materials. In this context, biopolymeric nanoparticles have attracted great attention in the last few years due to their multiple applications especially in the field of biomedicine. Ionic liquids have emerged as promising solvents for use in a wide variety of chemical and biochemical processes for their extraordinary properties, which include negligible vapor pressure, high thermal and chemical stability, lower toxicity than conventional organic solvents, and the possibility of tuning their physical–chemical properties by choosing the appropriate cation and anion. We here review the published works concerning the synthesis of biopolymeric nanoparticles using ionic liquids, such as trimethylsilyl cellulose or silk fibroin. We also mention our recent studies describing how high-power ultrasounds are capable of enhancing the dissolution process of silk proteins in ionic liquids and how silk fibroin nanoparticles can be directly obtained from the silk fibroin/ionic liquid solution by rapid desolvation in polar organic solvents. As an example, their potential biomedical application of curcumin-loaded silk fibroin nanoparticles for cancer therapy is also discussed.

Part of the book: Recent Advances in Ionic Liquids

By Guzmán Carissimi, Mercedes G. Montalbán, Marta G. Fuster and Gloria Víllora

This chapter presents a review on the design of nanoparticles which have been proposed as drug delivery systems in biomedicine. It will begin with a brief historical review of nanotechnology including the most common types of nanoparticles (metal nanoparticles, liposomes, nanocrystals and polymeric nanoparticles) and their advantages as drug delivery systems. These advantages include the mechanism of increased penetration and retention, the transport of insoluble drugs and the controlled release. Next, the nanoparticle design principles and the routes of administration of nanoparticles (parental, oral, pulmonary and transdermal) are discussed. Different routes of elimination of nanoparticles (renal and hepatic) are also analyzed.

Part of the book: 21st Century Nanostructured Materials

By Guzmán Carissimi, Mercedes G. Montalbán, Marta G. Fuster and Gloria Víllora

The use of nanoparticles in biomedical fields is a very promising scientific area and has aroused the interest of researchers in the search for new biodegradable, biocompatible and non-toxic materials. This chapter is based on the features of the biopolymer silk fibroin and its applications in nanomedicine. Silk fibroin, obtained from the Bombyx mori silkworm, is a natural polymeric biomaterial whose main features are its amphiphilic chemistry, biocompatibility, biodegradability, excellent mechanical properties in various material formats, and processing flexibility. All of these properties make silk fibroin a useful candidate to act as nanocarrier. In this chapter, the structure of silk fibroin, its biocompatibility and degradability are reviewed. In addition, an intensive review on the silk fibroin nanoparticle synthesis methods is also presented. Finally, the application of the silk fibroin nanoparticles for drug delivery acting as nanocarriers is detailed.

Part of the book: 21st Century Nanostructured Materials

By Mercedes G. Montalbán and Gloria Víllora

One of the crucial aspects in the design of processes of this millennium is the use of environmentally benign technologies. The introduction of supercritical fluids (SCF) and, in addition, their use with other solvents, such as ionic liquids, further diversify the applications of these fluids. SCF are powerful solvents with many unique properties. They have the mobility of gases and the dissolving power of liquid solvents, resulting in efficient high mass transfer rates and penetration into porous matrices. However, reliable and versatile mathematical models of phase equilibrium thermodynamics are needed for use in process design and viability studies. This chapter reviews experimental procedures for obtaining high-pressure phase equilibria data. In addition, phase diagrams describing binary mixtures and thermodynamic models capable of determining the conditions at phase equilibria at high pressures are considered.

Part of the book: Phase Equilibria With Supercritical Carbon Dioxide

By Mercedes G. Montalbán and Gloria Víllora

Currently, both humanity and the whole planet are living in a critical time, which leads us to look for more sustainable formulas to interact with the environment. One of the important changes in the design and operation of chemical processes is the search for environmentally friendly technologies. Many industrial processes are carried out under severe conditions or with reactants that involve the use of strong acids, toxic metal catalysts, organic solvents, and processes at high temperatures and/or pressures. Supercritical fluids (SCFs) and, among these, supercritical carbon dioxide (scCO2), have been revealed as promising environmentally friendly solvents, energy-efficient, selective, and capable of reducing waste, constituting an alternative to conventional organic solvents. The use of SCF, such as solvents and reaction media, makes it possible to work in less severe and more environmentally friendly conditions, even considerably increasing the efficiency of the processes. This chapter provides a brief review of the most important properties of SCF, with special emphasis on scCO2, as well as some of the most important applications.

Part of the book: Phase Equilibria With Supercritical Carbon Dioxide

By Mercedes G. Montalbán and Gloria Víllora

This chapter illustrates the collection of phase equilibrium and high-pressure solubility data applied to four binary systems, (CO2 + 2-pentanol, CO2 + vinyl butyrate, CO2 + 2-pentyl butyrate and CO2 + butyric acid) at three temperatures of (313.15, 323.15, and 333.15) K and pressures up to 11 MPa. These four organic compounds were selected because they are implicated in the kinetic resolution of rac-2-pentanol, and their phase equilibria play an important role in the separation processes of the reaction compounds. Equilibrium data were obtained using a synthetic method in a high-pressure cell of variable volume. All systems were found to have type I phase behavior. Experimental high-pressure data showed a good correlation with density-based models and by the well-known Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) EoS coupled with the quadratic mixing rule in a semipredictive approach to describe the phase equilibrium topology of the four binary mixtures.

Part of the book: Phase Equilibria With Supercritical Carbon Dioxide