Electroplating lithium transition metal oxides.

Materials synthesis often provides opportunities for innovation. We demonstrate a general low-temperature (260°C) molten salt electrodeposition approach to directly electroplate the important lithium-ion (Li-ion) battery cathode materials LiCoO2, LiMn2O4, and Al-doped LiCoO2. The crystallinities and electrochemical capacities of the electroplated oxides are comparable to those of the powders synthesized at much higher temperatures (700° to 1000°C). This new growth method significantly broadens the scope of battery form factors and functionalities, enabling a variety of highly desirable battery properties, including high energy, high power, and unprecedented electrode flexibility

Modulation of the peripheral blood transcriptome by the ingestion of probiotic yoghurt and acidified milk in healthy, young men

The metabolic health benefits of fermented milks have already been investigated using clinical biomarkers but the development of transcriptomic analytics in blood offers an alternative approach that may help to sensitively characterise such effects. We aimed to assess the effects of probiotic yoghurt intake, compared to non-fermented, acidified milk intake, on clinical biomarkers and gene expression in peripheral blood. To this end, a randomised, crossover study was conducted in fourteen healthy, young men to test the two dairy products. For a subset of seven subjects, RNA sequencing was used to measure gene expression in blood collected during postprandial tests and after two weeks daily intake. We found that the postprandial response in insulin was different for probiotic yoghurt as compared to that of acidified milk. Moreover changes in several clinical biomarkers were associated with changes in the expression of genes representing six metabolic genesets. Assessment of the postprandial effects of each dairy product on gene expression by geneset enrichment analysis revealed significant, similar modulation of inflammatory and glycolytic genes after both probiotic yoghurt and acidified milk intake, although distinct kinetic characteristics of the modulation differentiated the dairy products. The aryl hydrocarbon receptor was a major contributor to the down-regulation of the inflammatory genesets and was also positively associated with changes in circulating insulin at 2h after yoghurt intake (p = 0.05). Daily intake of the dairy products showed little effect on the fasting blood transcriptome. Probiotic yoghurt and acidified milk appear to affect similar gene pathways during the postprandial phase but differences in the timing and the extent of this modulation may lead to different physiological consequences. The functional relevance of these differences in gene expression is supported by their associations with circulating biomarkers

Nanoparticle transport via holographic photopolymerization

This thesis studies methods of engineering the placement of nanoparticle with sub-micron resolution over macroscopic size scales. Such control holds great promise as an inexpensive methodology for manufacturing devices, such as optical elements, with enhanced functionality and properties. Specifically, we have examined the addition of silica nanoparticles into holographic photopolymerization systems for the purpose of controlling the location of the nanoparticle within the periodic structure based upon control of the surface chemistry of the nanoparticle. Herein we report the successful sequestration of methacrylate functionalized, silica nanoparticles into the polymeric domain of phase separated, liquid crystal—acrylate composite structures with regular, submicron periodicities. TEM analysis of the resultant Bragg gratings indicated that the nanoparticles were fully dispersed within the polymer. Optical characterization of the grating structures indicated that the particles did not negatively impact the optical properties of the grating, and enhanced the switching properties of the liquid crystal structure due to the roughly lamellar morphology of the liquid crystal droplets when the nanoparticle are present in the formulation. The successful functionalization of the nanoparticle surface was confirmed using NMR analysis. It was noted experimentally that at large, excess concentrations of the nanoparticle functionalization agent, a hybrid organic—siloxane corona was physisorbed onto the nanoparticle surface, imparting liquid-like properties to the nanoparticles without the presence of solvents. It was then demonstrated using SAXS analysis that one could achieve FCC structures with these highly viscous liquids containing up to 60% inorganic content. Because the corona is polymerizable, the structure can then be fixed in place. Excellent dispersion and isolation in the polymer domain was also demonstrated for high loadings (up to 20 wt%) of the same reactive silica nanoparticles in holographic syrups containing thiol-ene monomers. Because thiol-ene polymers have significant advantages over acrylates for these systems due to the step-growth polymerization mechanism, this system was chosen for further development as a method to create defined nanoparticle polymer hybrid structures. To guide future development efforts, real-time monitoring of grating development was conducted to increase knowledge of system variability. It was noted here that the addition of nanoparticles delays grating formation in a fashion linear with nanoparticle loading. In order to help understand the mechanism by which nanoparticles delay grating formation, the step-growth, holographic process was modeled using a reaction diffusion system that treats component diffusion as following Stokes-Einstein driven by pure concentration gradients. Ignoring the thermodynamic interactions proved to be an inadequate assumption, so the model was re-accomplished using Flory-Huggins Polymer—Solution Theory to account for free energy using an experimentally derived χ between the polymer and liquid crystal and by assuming that the nanoparticle could be treated as a polymer with a radius of gyration equal the nanoparticle radius. This model qualitatively matched the experimental observations and roughly predicted that the delay in grating formation was due to reactive incorporation of the nanoparticle into the polymer, which greatly slowed polymer diffusion. It was then speculated that this increased viscosity delayed phase separation, although phase separation was not treated directly with this model

Self-Assembled Hierarchical Structure of Fullerene Building Blocks; Single-Walled Carbon Nanotubes and C\u3csub\u3e60\u3c/sub\u3e

We report a self-assembled hierarchical nanostructure produced by mixing two carbon nanobuilding blocks—fullerene nanospheres (C60) and (10,10) armchair single-walled carbon nanotubes— at ambient temperature and pressure. It was found that upon mixing the fullerene building blocks, they self-assemble into films with smectic liquid crystal-like periodicity. The films wrap around to form nanospheres (50 to 150 nm in diameter) with central cavities resembling pitted nanofruits that are connected by a network of stems. Raman spectroscopy showed 10 cm–1 softening in the frequency of the G+ mode of the assembled nanotubes indicating significant alteration in the assembly’s electronic structure. The current findings point out a new rich subject to explore which could promote engineered nanostructured assemblies leading to many advances in materials science and biological and environmental fields

Self-Assembled Hierarchical Structure of Fullerene Building Blocks; Single-Walled Carbon Nanotubes and C\u3csub\u3e60\u3c/sub\u3e

We report a self-assembled hierarchical nanostructure produced by mixing two carbon nanobuilding blocks—fullerene nanospheres (C60) and (10,10) armchair single-walled carbon nanotubes— at ambient temperature and pressure. It was found that upon mixing the fullerene building blocks, they self-assemble into films with smectic liquid crystal-like periodicity. The films wrap around to form nanospheres (50 to 150 nm in diameter) with central cavities resembling pitted nanofruits that are connected by a network of stems. Raman spectroscopy showed 10 cm–1 softening in the frequency of the G+ mode of the assembled nanotubes indicating significant alteration in the assembly’s electronic structure. The current findings point out a new rich subject to explore which could promote engineered nanostructured assemblies leading to many advances in materials science and biological and environmental fields

Exploring Two-Dimensional Soap-Foam Films using Fullerene (C60) Nanosensors

A large number of studies have been devoted to the investigation of foam structure formation, characteristics, and stability. In this paper, we use fullerene (C60) spheres as Raman active nanosensors to probe the local chemical environment in a two-dimensional soap foam. It has been found that the position of the Raman active pentagon pinch mode around 1469 cm−1 shifts to lower wave numbers with the increase in the angle between foam-cell boundaries. The observed shift is due to changes in the local chemical interaction between the nanosensor and its environment. The study demonstrates that fullerenes may be used as sensitive nanoscale sensors to probe the local chemical potential in soft and interfacial materials, and more importantly in thermodynamically small systems

Exploring Two-Dimensional Soap-Foam Films using Fullerene (C60) Nanosensors

A large number of studies have been devoted to the investigation of foam structure formation, characteristics, and stability. In this paper, we use fullerene (C60) spheres as Raman active nanosensors to probe the local chemical environment in a two-dimensional soap foam. It has been found that the position of the Raman active pentagon pinch mode around 1469 cm−1 shifts to lower wave numbers with the increase in the angle between foam-cell boundaries. The observed shift is due to changes in the local chemical interaction between the nanosensor and its environment. The study demonstrates that fullerenes may be used as sensitive nanoscale sensors to probe the local chemical potential in soft and interfacial materials, and more importantly in thermodynamically small systems

Effect of Linear Alcohol Molecular Size on the Self-Assembly of Fullerene Whiskers

The recent development of self-assembled fullerene whiskers and wires has created an enormous potential and resolved a serious challenge for utilizing such unique class of carbon material in advanced nano-scale, molecular-based electronic, optical, and thermal devices. In this paper we investigate, the self-assembly of C60 molecules into one-dimensional whiskers using a series of linear alcohols H(CH2)nOH, with n changing from 1 (methanol) to 3 (isopropyl alcohol), to elucidate the effect of alcohol molecular size on the size distribution of the self-assemble fullerene whiskers. Our results show that the length of the produced fullerene whiskers is affected by the molecular size of the alcohol used in the process. The crucial role played by solvent/alcohol interaction in the assembly process is discussed. In addition, Raman spectroscopy measurements support the notion that the self-assembled whiskers are primarily held by depletion forces and no evidence of fullerene polymerization was observed

Effect of Linear Alcohol Molecular Size on the Self-Assembly of Fullerene Whiskers

The recent development of self-assembled fullerene whiskers and wires has created an enormous potential and resolved a serious challenge for utilizing such unique class of carbon material in advanced nano-scale, molecular-based electronic, optical, and thermal devices. In this paper we investigate, the self-assembly of C60 molecules into one-dimensional whiskers using a series of linear alcohols H(CH2)nOH, with n changing from 1 (methanol) to 3 (isopropyl alcohol), to elucidate the effect of alcohol molecular size on the size distribution of the self-assemble fullerene whiskers. Our results show that the length of the produced fullerene whiskers is affected by the molecular size of the alcohol used in the process. The crucial role played by solvent/alcohol interaction in the assembly process is discussed. In addition, Raman spectroscopy measurements support the notion that the self-assembled whiskers are primarily held by depletion forces and no evidence of fullerene polymerization was observed