Unconventional nanofabrication techniques; both those which have been newly developed and those under development, had brought inexpensive, facile, yet high quality means to fabricate nanostructures that have feature sizes of less than 100 nm in industry and academia. This dissertation focuses on developing unconventional fabrication techniques, building studying platforms, and studying the mechanisms behind them. The studies are divided into two main facets and four chapters. The first facet, in Chapter II and Chapter III, deals with the research and development of different nanofabrication techniques and nanostructures. These techniques include litho-synthesis, colloidal lithography, and photolithography. The nanostructures that were fabricated by these techniques include the metal nanoparticle arrays, and the self-assembled CdSe nanoring arrays. At the same time, the dissertation provides mechanisms and models to describe the physical and chemical nature of these techniques. The second area of this study, in Chapter III to Chapter V, presents the applications of these nanostructures in fundamental studies, i.e. the mechanisms of plasmon enhanced fluorescence and photo-oxidation kinetics of CdSe quantum dots, and applications such as molecular sensing and material fabrication. More specifically, these applications include tuning the optical properties of CdSe quantum dots, biomodification of CdSe quantum dots, and copper ion detection using plasmon and photo enhanced CdSe quantum dots. We have successfully accomplished our research goals in this dissertation. Firstly, we were able to tune the emission wavelength of quantum dots, blue-shifted for up to 45 nm, and their surface functionalization with photo-oxidation. A kinetic model to calculate the photo-oxidation rates was established. Secondly, we established a simple mathematical model to explain the mechanism of plasmon enhanced fluoresce of quantum dots. Our calculation and experimental data support the fluorescence resonance energy transfer (FRET) mechanism between quantum dots and the metal nanoparticles. Thirdly, we successfully pattered the CdSe quantum dots (diameter ~4 nm) into nanorings with tunable diameters and annular sizes on different substrates. We also established a physical model to quantitatively explain the mechanism with the forces that involved in the formation of the nanorings.

This study focuses on various aspects of nanocrystals embedded in a dielectric matrix. In the first part of this work, a new approach with the use of Fourier Transform Infrared spectroscopy (FTIR) in the nanocrystal analysis was developed and presented. Si and Ge nanocrystals embedded in SiO2 matrix were mainly studied. This new approach is based on the analysis of structural variations of SiO2 matrix during the formation of semiconductor nanocrystlas. It is shown that the chemical and structural variations of the host matrix are directly related to the precipitation of nanocrystals in it. This correlation provides valuable information about the presences of nanocrystals in the matrix. In the second part of this work, fabrication of SiC films with and without Si nanocrystals inclusions was studied. With this aim, stoichiometric SiC and Si rich SiC thin films were fabricated by using magnetron co-sputtering and Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques. For SiC films, the structural and optical analyses were performed. For Si rich SiC films, the formation conditions of Si nanocrystals were investigated. Post annealing studies were carried out to track the evolution of the SiC matrix and formation of Si nanocrystals at different temperatures. Chemical and structural properties of the SiC host matrix were investigated with FTIR spectroscopy. Optimum conditions for the fabrication of stoichiometric SiC layers were determined. The crystallography of the nanocrystals was investigated by X-Ray Diffraction (XRD). The variation of the atomic concentrations and bond formations were investigated with X-Ray Photoelectron Spectroscopy (XPS). Raman spectroscopy and Transmission Electron Microscopy (TEM) were used to verify the formation of Si nanocrystals. We have shown that both single and multilayer Si nanocrystals can be fabricated in the amorphous SiC matrix for applications such as light emitting diodes and solar cells.

Biomedicine has recently exploited many nanotechnology platforms for the detection and treatment of disease as well as for the fundamental study of cellular biology. A prime example of these successes is the implementation of semiconductor quantum dots in a wide range of biological and medical applications, from in vitro biosensing to in vivo cancer imaging. Quantum dots are nearly spherical nanocrystals composed of semiconductor materials that can emit fluorescent light with high intensity and a strong resistance to degradation. The aim of this thesis is to understand the fundamental physics of colloidal quantum dots, to engineer their optical and structural properties for applications in biology and medicine, and to examine the interaction of these particles with biomolecules and living cells. Toward these goals, new synthetic strategies for colloidal nanocrystals have been developed, implementing a cation exchange method for independent tuning of size and fluorescence, and a bandgap engineering technique that utilizes mechanical strain imposed by coherent shell growth. In addition, stable nanocrystals have been prepared with ultrathin coatings (< 2 nm), 'amphibious' solubility, and broadly tunable bioaffinity, induced by self-assembly with polyhistidine-sequences on recombinant proteins. Finally, colloidal quantum dots have been studied in biological fluids and living cells in order to elucidate their interactions with biological systems. It was found that these interactions are strongly dependent on the size of the nanocrystal, and cytotoxic effects of these particles are largely independent of their composition of heavy metal atoms, demonstrating that the rule book for toxicology must be rewritten for nanomaterials.

Mg-based alloys form a variety of interesting structures including stable and metastable crystalline, stable and metastable quasicrystalline, nanocrystalline and amorphous phases. Many of these phases can be made to coexist by suitable processing leading to an interesting combination of properties. Non-equilibrium processing in combination with suitable heat treatments can be used to control the scale and dispersion of these phases. Further thrust to Mg-based alloys is expected through the development of Mg-based bulk metallic glasses. Magnesium matrix composites are also gaining in prominence. The thesis has been divided into theoretical and experimental parts. The theoretical part focuses on understanding the structure of quasicrystals, rational approximants and related structures. The experimental work involves synthesis, non-equilibrium processing and characterization of specific Mg-based alloys. The structure of quasicrystals and related structures can be understood by working in three dimensions or by projection from higher dimensions. The projection formalism is used to generate quasicrystals and rational approximants in 2D and 3D. Approximants to the Penrose lattice are generated with directions of approximation oriented 90° and 72° apart. Rational approximants to the icosahedral quasilattice are generated and the systematics of lattice-centring in these approximants analysed. Two-dimensional quasiperiodic lattice with 5-fold symmetry, which is periodic along the third dimension, is generated as an approximant to the icosahedral lattice. Approximants are also considered wherein quasiperiodicity is retained along one or two directions. The concept of average lattices can be used to understand diverse structures including vacancy ordered phases (VOP) and orthorhombic approximants to the decagonal phase. VOP which lack incommensurate length scales should be considered as quasiperiodic superlattice (QPSL) approximants rather than as conventional rational approximants and hence have the average lattice scheme built into them. The average lattice approach is further used to unify Kuo’s and Anantharaman's models for orthorhombic approximants to the decagonal quasicrystal. A modified version of Anantharaman's model is also presented. Using the twinned icosahedron model, Robinson and Taylor approximants to the decagonal quasicrystal are generated by the twinning of Mackay and Little approximants to the icosahedral quasicrystal. An indexing scheme based on this model is developed which inherits the merits of the twinned icosahedron model. Further, using cluster of four icosahedra, in a distorted tetrahedral configuration, symmetries of the hexagonal phases, which are related to quasicrystals, are generated. Frank's ratio is brought out as a unifying thread connecting diverse kinds of structures including VOP and hexagonal phases related to quasicrystals, which have pseudocubic symmetry. Experimental work involves the synthesis and characterization of alloys in four systems: a) Mg-Zn-Y, b) Mg-Zn-La, c) Al-Mg-Cu and d) Mg-Cu-Y. Induction melting is used to prepare the alloys and melt-spinning is used as the primary non-equilibrium processing route. The focus in the Mg-Zn-RE systems is in the as cast condition while in the Al-Mg-Cu system it is in the melt-spun condition. Characterization techniques used are XRD, SEM and TEM. In the Mg-Zn-Y system face-centred icosahedral (FC1) phase with quasilattice parameter of 5.21 A is found to coexist with related crystalline phases in the Mg4Zn94Y2 and Mg23Zn5gY9 alloys. A series of crystalline phases with superlattice ordering are seen in the Mg-Zn-Y and Mg-Zn-La systems. These phases with a variety of ordering, many of which display interesting patterns of streaking in the SAD pattern, are related to one-another and to the FCI QC found in the Mg-Zn-Y system. No quasicrystal could be observed in the two alloys investigated in the Mg-Zn-La system with La = 5 and 8 %. Conventional rational approximants were conspicuous by there absence in both the rare-earth containing systems. This is understood in terms of the absence of large clusters in these systems. High Y alloys display a tendency to form nanocrystals in the as-cast condition and amorphous regions are observed in the as-cast alloys with Y > 20 %. Hence, high Y alloys are anticipated to be bulk glass formers. Melt-spinning of the alloys in both the RE containing systems lead to the formation of nanocrystalline regions. The e/a ratio plays an important role in the formation of phases in the Mg-Zn-Y system. An e/a ratio near 2.08 has a stabilising effect on a variety of phases including the FCI quasicrystal, ternary phases related to the quasicrystal and binary phases like YZn12 and Y2Zn17. Formation of quasicrystals in the Al-Mg binary and Mg-Al-Cu ternary seem to be very sensitive to processing conditions and were not observed in the present investigation in the melt-spun alloys. However, β-Al3Mg2 and Mg32(Al,Cu)49 phases with large lattice parameters, which are related to quasicrystals, are observed in as-cast and melt-spun conditions. The Mg32(Al,Cu)49 phase brings out the similarity between this system and the Mg-Al-Zn system. The glass formability of the alloys in the Al-Mg binary and in the Mg-Al-Cu ternary is limited. Except for the formation of amorphous phase in some regions, the alloys were crystalline even when melt-spun at 2800 rpm. The ability to form nanocrystals is also limited in this system as compared to the Mg-Zn-RE systems. Often melt-spun alloys showed a wide range of grain sizes coexisting together.

Computational approaches play an important role in today's materials science owing to the remarkable advances in modern supercomputing architecture and algorithms. Ab initio simulations solely based on a quantum description of matter are now very able to tackle materials problems in which the system contains up to a few thousands atoms. This dissertation aims to address the modern electronic structure calculation methods applied to a range of various materials such as liquid and amorphous phase materials, nanostructures, and small organic molecules. Our simulations were performed within the density functional theory framework, emphasizing the use of real-space ab initio pseudopotentials. On the first part of our study, we performed liquid and amorphous phase simulations by employing a molecular dynamics technique accelerated by a Chebyshev-subspace filtering algorithm. We applied this technique to find l- and a- SiO₂ structural properties that were in a good agreement with experiments. On the second part, we studied nanostructured semiconducting oxide materials, i.e., SnO₂ and TiO₂, focusing on the electronic structures and optical properties. Lastly, we developed an efficient simulation method for non-contact atomic force microscopy. This fast and simple method was found to be a very powerful tool for predicting AFM images for many surface and molecular systems. / text

Cellulose nanofibrils (CNFs) are nanoscale fibers of high aspect ratio that can be isolated from a wide variety of cellulosic sources, including wood and bacterial cellulose. With high strength despite of their low density, CNFs are a promising renewable building block for the preparation of nanostructured materials and composites. To fabricate CNF-based materials with improved inherent rheological and mechanical properties and additional new functionalities, it is essential to tailor the surface properties of individual CNFs. The surface structures control the interactions between CNFs and ultimately dictate the structure and macroscale properties of the bulk material. In this thesis we have demonstrated different approaches, ranging from non-covalent adsorption and covalent chemical modification to modification of cellulose biosynthesis, to tailor the structure and surface functionalities of CNFs for the fabrication of advanced materials. These materials possess enhanced properties such as water-redispersibility, water absorbency, dye adsorption capacity, antibacterial activity, and mechanical properties. In Paper I, CNFs were modified via the irreversible adsorption of carboxymethyl cellulose (CMC). The adsorption of small amounts of CMC onto the surface of CNFs prevented agglomeration and co-crystallization of the nanofibrils upon drying, and allowed the recovery of rheological and mechanical properties after redispersion of dried CNF samples. In Paper II, CNFs bearing permanent cationic charges were prepared through quaternization of wood pulp fibers followed by mechanical disintegration. The activation of the hydroxyl groups on pulp fibers by alkaline treatment was optimized prior to quaternization. This optimization resulted in individual CNFs with uniform width and tunable cationic charge densities. These cationic CNFs demonstrated ultrahigh water absorbency and high adsorption capacity for anionic dyes. In Paper III, via a similar approach as in Paper II, CNFs bearing polyethylene glycol (PEG) were prepared by covalently grafting PEG to carboxylated pulp fibers prior to mechanical disintegration. CNFs with a high surface chain density of PEG and a uniform width were oriented to produce macroscopic ribbons simply by mechanical stretching of the CNF hydrogel network before drying. The uniform grafted thin monolayer of PEG on the surface of individual CNFs prevented the agglomeration of CNFs and facilitated their alignment upon mechanical stretching, thus resulted in ribbons with ultrahigh tensile strength and modulus. These optically transparent ribbons also demonstrated interesting biaxial light scattering behavior. In Paper IV, bacterial cellulose (BC) was modified by the addition of chitin nanocrystals (ChNCs) into the growing culture medium of the bacteria Acetobacter aceti which secretes cellulose in the form of entangled nanofibers. This led to the in situ incorporation of ChNCs into the BC nanofibers network and resulted in BC/ChNC nanocomposites exhibiting bactericidal activity. Further, blending of BC nanofibers with ChNCs produced nanocomposite films with relatively lower tensile strength and modulus compared to the in situ cultivated ones. The bactericidal activity increased significantly with increasing amount of ChNCs for nanocomposites prepared by direct mixing of BC nanofibers and ChNCs. In Paper V, CNFs were isolated from suspension-cultured wild-type (WT) and cellulose-binding module (CBM) transformed tobacco BY-2 (Nicotiana tabacum L. cv bright yellow) cells. Results from strong sulfuric acid hydrolysis indicated that CNFs from transgenic cells overexpressing CBM consisted of longer cellulose nanocrystals compared to CNFs from WT cells. Nanopapers prepared from CNFs of transgenic cells demonstrated significantly enhanced toughness compared to CNFs of WT cells. / <p>QC 20141103</p> / CARBOMAT

There is a demand for new straightforward approaches for stabilization and solubilization of various nanoparticulate materials in their colloidal form, that pave way for fabrication of materials possessing compatibility with wide range of dispersing media. Therefore in this thesis a new general method to form stable nanocrystals in water and organics using amphiphilic polymers generated through simple and low cost techniques is presented and discussed. Amphiphilic coating agents are formed using thiolated or carboxylated polyethylene glycol methyl ether (mPEG-SH) as a starting material. These materials are available with a wide variety of chain lengths. The method of obtaining of amphiphilic NPs is quite general and applicable for semiconductor CdTe nanocrystals as well as nanoscale noble metal (Au) and magnetic (Fe3O4) particles. This approach is based on anchoring PEG segment to the surface of a nanoparticle to form an amphiphilic palisade. Anchoring is realized via interaction of –SH (for CdTe and Au) or –COOH (in the case of magnetite) functional groups with particle’s surface. The resulting amphiphilicity of the nanocrystals is an inherent property of their surface and it is preserved also after careful washing out of solution of any excess of the ligand. The nanocrystals reversibly transfer between different phases spontaneously, i.e. without any adjustment of ionic strength, pH or composition of the phases. Such reversible and spontaneous phase transfer of nanocrystals between solvents of different chemical nature has a great potential for many applications as it constitutes a large degree of control of nanocrystals compatibility with technological processes or with bio-environments such as water, various buffers and cell media as well as their assembly and self-assembly capabilities.

Nanokristalle werden beispielsweise für eine Anwendung in Solarzellen, Lichtemittern und nichtflüchtigen Datenspeichern diskutiert. Damit diese Anwendungen funktionieren können, ist eine genaue Kontrolle der Kristallitgröße sowie der Flächendichte und Lage der Kristallite in der Matrix wichtig. Zudem sollte die Matrix amorph sein, da amorphe Matrixmaterialien die Nanokristall-Oberfläche besser passivieren und beständiger gegen Leckströme sind. In dieser Arbeit werden Ge-Nanokristalle in die Hoch-Epsilon-Dielektrika ZrO2 und TaZrOx eingebettet. Im System Ge/ZrO2 kristallisieren die Ge-Cluster und die ZrO2-Matrix bei der gleichen Temperatur. Aufgrund der kristallinen Matrix weicht die Form der Ge-Nanokristalle von einer Kugel ab, worunter unter anderem die Größenkontrolle leidet. Die Beimischung von Ta2O5 stabilisiert die amorphe Phase des ZrO2 und verhindert dadurch die gemeinsame Kristallisation. Dadurch wird es im System Ge/TaZrOx möglich, kugelförmige Ge-Nanokristalle im Größenbereich von 3 nm bis 6 nm positionskontrolliert in eine amorphe Matrix einzubetten. Für die Untersuchung einer möglichen Anwendung des Materialsystems wurden Speicherzellen eines nichtflüchtigen Datenspeichers auf Basis von Ge-Nanokristallen hergestellt. Dabei zeigte sich, dass das System Ge/TaZrOx überdurchschnittlich viele Ladungen speichert und daher für diese Anwendung vielversprechend ist. Zudem stabilisiert die Beimischung von Ta2O5 eine extrem seltene orthorhombische Modifikation des ZrO2. Für ferroelektrische Datenspeicher könnte diese Phase eine aussichtsreiche Alternative zum HfO2 sein.

Abstract Flotation is a well-known and widely used technique for the separation of particles smaller than 250 µm, but efficient performance requires the use of various synthetic chemicals which can potentially damage the health of humans and animals and pollute the environment. Consequently, their replacement through a more environment-friendly and sustainable alternative has been demanded. One promising candidate is cellulose, which is an abundant natural polymer that is environment-friendly and can be treated chemically and physically to yield tailored properties and thus a potential for use in processes such as flotation. This work focuses on the use of cellulose-based reagents in flotation processes to replace the often harmful conventional reagents derived from mineral oil, plant oils or animal fats. The physico-chemical properties of cellulose differ from those of conventional reagents, leading to differences in performance during flotation. In particular, the chemical and morphological heterogeneity of cellulose affects its properties and thus its interaction with minerals and water. Consequently, its use requires the study of the fundamentals of flotation and their application including the physico-chemical heterogeneity of cellulose to determine the optimum conditions and enable efficient performance. This work focuses on the determination of the thermodynamic surface energetics of solid particles and changes in this after reagent adsorption, using the inverse gas chromatography technique in a dry atmosphere. Furthermore, interactions between cellulose and minerals immersed in water are investigated using the DLVO theory, the interaction forces between cellulose and the minerals being derived and correlated with flotability. The importance of free surface charges is then considered by investigating the electric surface potential of cellulose-coated minerals in connection with particle-bubble attachment efficiency. At the same time, conventional amphiphilic reagents are used and its performances are related to cellulose-based reagents. / Tiivistelmä Vaahdotus on kaivannaisteollisuudessa laajasti käytössä oleva prosessi, jonka avulla saadaan erotettua tehokkaasti pieniä, alle 250 µm kokoisia partikkeleita. Vaahdotuksen apuaineena käytetään erilaisia synteettisiä kemikaaleja, jotka voivat aiheuttaa harmia ympäristölle. Siksi niiden korvaaminen ympäristöystävällisemmillä vaihtoehdoilla on tärkeää. Yksi lupaava vaihtoehto korvaavaksi materiaaliksi on selluloosa. Selluloosa on uusiutuva ja ympäristöystävällinen luonnonpolymeeri, josta voidaan valmistaa kemiallisesti ja fysikaalisesti käsittelemällä erilaisia biokemikaaleja. Näitä voidaan soveltaa erilaisissa prosesseissa, myös vaahdotuksessa. Tässä työssä keskitytään selluloosapohjaisten kemikaalien käyttöön vaahdotuksessa tavanomaisten, usein haitallisten synteettisten kemikaalien korvaamiseksi. Selluloosan fysikaaliskemialliset ominaisuudet eroavat synteettisten vaahdotuskemikaalien ominaisuuksista, mikä vaikuttaa niiden vuorovaikutukseen mineraalien ja veden kanssa. Erityisesti selluloosan kemiallinen ja morfologinen heterogeenisuus on keskeinen tekijä. Selluloosan hyödyntäminen tulevaisuuden vaahdotuskemikaalina edellyttää selluloosan ja mineraalien vuorovaikutuksen syvällistä ymmärtämistä. Tässä työssä tutkitaan selluloosan ja mineraalien vuorovaikutusta sekä IGC-menetelmän avulla, että DLVO-teorian että pintavarausmittausten avulla. Lisäksi tutkitaan selluloosan ja mineraalien vuorovaikutusvoimien yhteyttä vaahdotusprosessin onnistumiseen ja saavutettuja tuloksia verrataan kaupallisten reagenssien toimintaan.

Made available in DSpace on 2016-07-01T11:59:27Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 3.pdf: 9217684 bytes, checksum: c6a2ecaa489f6ad864c3dd0909b2d127 (MD5) Previous issue date: 2016 / Made available in DSpace on 2016-07-21T14:39:30Z (GMT). No. of bitstreams: 2 3.pdf: 9217684 bytes, checksum: c6a2ecaa489f6ad864c3dd0909b2d127 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2016 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos/Farmanguinhos. Rio de Janeiro, RJ, Brasil. / O efavirenz é um antirretroviral amplamente utilizado no tratamento de HIV, porém este fármaco encontra problemas de biodisponibilidade devido à sua baixa dissolução em meio aquoso. Nanocristais de fármaco são uma forma considerada segura de aumentar a dissolução sem promover uma alteração na molécula. Seu preparo pode ser feito por diferentes técnicas, uma delas é a nanocristalização por antissolvente. Que consiste na precipitação de fármaco a partir de uma fase orgânica, inserindo-a em uma fase aquosa, na qual o fármaco é pouco solúvel. Esta técnica é considerada promissora pois frente a outros tipos de método de preparo tem menor demanda energética, de tempo e custo. O uso de nanocristais preparados por esta técnica é uma alternativa promissora para alcançar o incremento da dissolução. No presente trabalho foram preparados nanocristais de efavirenz testando-se diferentes condições experimentais. Como resultado foram obtidas suspensões que foram levadas então a secagem. O pó obtido foi caracterizado por técnicas de espectroscopia de IV, para identificação da estrutura química; DRX para verificação da cristalinidade e MEV a fim de observar a morfologia das partículas formadas. Também foi realizado ensaio de dissolução por dispersão. Uma vez obtidos os perfis das amostras, foi possível comparar os resultados e realizar alterações necessárias a fim de otimizar uma formulação como alterações nas concentrações de estabilizantes, no grau de saturação do sistema, no método de agitação, dentre outras. Também foi realizado um estudo inicial acerca da estabilidade física das suspensões formadas utilizando técnicas de espalhamento de luz. Por fim, foram encontradas algumas formulações que promoveram grande incremento na dissolução, a que teve melhor desempenho combinava uso de precipitação seguida por moagem em moinho coloidal.A análise da suspensão mostrou controle eficaz do tamanho de partícula, no que diz respeito tanto ao tamanho em escala nanométrica quanto redução na polidispersão das partículas; foi visto por DRX que esta amostra manteve a mesma estrutura cristalina da matériaprima, no IV não foi revelada qualquer reação química entre EFV e estabilizantes. O ensaio de dissolução apresentou incremento significativo do perfil, atingindo 98% de eficiência de dissolução. / Efavirenz is an antiretroviral widely used in the treatment of HIV, but this drug has bioavailability problems due to their low dissolution in an aqueous medium. Drug nanocrystals are considered a safe way to enhance dissolution without causing a change in the molecule. They can be prepared by different techniques, one of which is nanocrystallization by antisolvent. It constitutes in drug precipitation from an organic phase by adding it in an aqueous phase, in which the drug is poorly soluble. This technique is considered promising when compared to other preparation methods due to low energy, time and cost required. The use of nanocrystals prepared by this technique is a promising alternative to achieve a dissolution enhancement. In the present work, we prepared efavirenz nanocrystals by testing different experimental conditions. The obtained suspensions were dried. The powder was characterized by IR spectroscopy techniques for identification of chemical structure, XRD for verifying the crystallinity and SEM in order to observe the morphology of the particles. The dissolution test by dispersion was also conducted. Once obtained the profiles of the samples, it was possible to compare the results and make necessary changes to optimize the formulations such as, changes in stabilizers concentrations, the degree of system saturation and the agitation method, among others. An initial study on the physical stability of the suspensions formed, using light scattering techniques was also carried out. Finally, we found some formulations that promoted large increase in dissolution profile. The one with the best performance combined precipitation followed by grinding in colloid mill. The suspension analysis exhibited effective control of particle size, as regards both the size at the nanometer scale as the reduction in the polydispersity of the particles; XRD showed that the sample maintained the same crystal structure of the raw material; the IV did not revealed any chemical reaction between EFV and stabilizers. The dissolution test presented large enhancement of the profile, reaching 98% dissolution efficiency.