Despite considerable advances in recent years, challenges in delivery and storage of biological drugs persist and may delay or prohibit their clinical application. Though nanoparticle-based approaches for small molecule drug encapsulation are mature, encapsulation of proteins remains problematic due to destabilization of the protein. Reverse micelles composed of decylmonoacyl glycerol (10MAG) and lauryldimethylamino-N-oxide (LDAO) in low-viscosity alkanes have been shown to preserve the structure and stability of a wide range of biological macromolecules.
View Article and Find Full Text PDFGrowing ultrathin nanogranular (NG) metallic films with continuously varying thickness is of great interest for studying regions of criticality and scaling behaviors in the vicinity of quantum phase transitions. In the present work, an ultrathin gold plasmonic NG film was grown on a sapphire substrate by RF magnetron sputtering with an intentional deposition gradient to create a linearly variable thickness ranging from 5 to 13 nm. The aim is to accurately study the electronic phase transition from the quantum tunneling regime to the metallic conduction one.
View Article and Find Full Text PDFThe combination of protein and polysaccharides with magnetic materials has been implemented in biomedical applications for decades. Proteins such as silk, collagen, and elastin and polysaccharides such as chitosan, cellulose, and alginate have been heavily used in composite biomaterials. The wide diversity in the structure of the materials including their primary monomer/amino acid sequences allow for tunable properties.
View Article and Find Full Text PDFACS Biomater Sci Eng
December 2019
In ferroelectrics, manifestation of a strong electromechanical coupling is attributed to both engineered domain morphology and phase transformations. However, realization of large sustainable and reversible strains and polarization rotation has been limited by fatigue, nonlinearity and hysteresis losses. Here, we demonstrate that large strain and polarization rotation can be generated for over 40 × 10(6) cycles with little fatigue by realization of a reversible ferroelectric-ferroelectric phase transition in [011] cut Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) relaxor ferroelectric single crystal.
View Article and Find Full Text PDFChemical and structural heterogeneity and the resulting interaction of coexisting phases can lead to extraordinary behaviours in oxides, as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. However, such phenomena are rare in metallic alloys. Here we show that, by tuning the presence of structural heterogeneity in textured Co(1-x)Fe(x) thin films, effective magnetostriction λ(eff) as large as 260 p.
View Article and Find Full Text PDFSynthesis of uniform silica shell over Co3O4 nanoparticles was carried out using the colloidal solutions of Tergitol and cyclohexane. The shell could be controlled to a thickness of up to 20 nm by varying different parameters such as the amount of tetraethylorthosilicate, concentration of Co3O4 nanoparticles, reaction time and the presence of water and 1-octanol. Control of the amount of water (required for hydrolysis) appears to be the key factor for controlling the shell thickness.
View Article and Find Full Text PDFFour new 5-aminoisophthalates of cobalt and nickel have been prepared employing hydro/solvothermal methods: [Co(2)(C(8)H(5)NO(4))(2)(C(4)H(4)N(2))(H(2)O)(2)].3H(2)O (I), [Ni(2)(C(8)H(5)NO(4))(2)(C(4)H(4)N(2))(H(2)O)(2)].3H(2)O (II), [Co(2)(H(2)O)(mu(3)-OH)(2)(C(8)H(5)NO(4))] (III), and [Ni(2)(H(2)O)(mu(3)-OH)(2)(C(8)H(5)NO(4))] (IV).
View Article and Find Full Text PDFAnisotropic growth of magnetite (Fe3O4) nanoparticles is achieved in a hydrothermal growth process using hexamine to play a dual role of oxide forming and directing agent. The samples are characterized by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, squid magnetometry, ferromagnetic resonance technique, diffuse reflectance spectroscopy and Mössbauer spectroscopy, which collectively establish the formation of Fe3O4 phase. Anisotropic structures such as nanorods and nanotubules are revealed and these are shown to exhibit good humidity sensing properties.
View Article and Find Full Text PDFChem Commun (Camb)
February 2009
Rod-shaped nanostructures of cobalt oxalate dihydrate were synthesized at room temperature by the microemulsion (reverse micellar) route. These rods are highly uniform in length and can be modified with temperature (from approximately 6.5 microm at 50 degrees C to approximately 2.
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