Synthetic and bio-hybrid nanoscale layers with tailored surface functionalities

Abstract We examine the prospective routes for the design of synthetic/biomacromolecular/inorganic film assemblies for photothermal cell based on biomimetic approach. We demonstrate examples of channel proteins immobilized onto surfaces of silicon single crystals modified with Langmuir-Blodgett and self-assembled monolayers. These proteins can be immobilized in intact, closed-pore conformation. Their state within photosensitive monolayers can be controlled by the photoisomerization reaction triggered by UV light

Thermoresponsive reversible behavior of multistimuli pluronic-based pentablock copolymer at the air-water interface

Surface behavior of the pH- and thermoresponsive amphiphilic ABCBA pentablock copolymer has been studied with respect to the environmental conditions. We demonstrate that the pentablock copolymer poly((diethylaminoethyl methacrylate)-b-(ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)-b-(diethylaminoethyl methacrylate)) possesses reversible temperature changes at the air-water interface in a narrow pH range of the water subphase. Significant diversity in the surface morphology of pentablock copolymer monolayers at different pH and temperatures observed were related to the corresponding reorganization of central and terminal blocks. Remarkable reversible variations of the surface pressure observed for the Langmuir monolayers at pH 7.4 in the course of heating and cooling between 27 and 50°C is associated with conformational transformations of terminal blocks crossing the phase line in the vicinity of the lower critical solution temperature point. The observed thermoresponsive surface behavior can be exploited for modeling of the corresponding behavior of pentablock copolymers adsorbed onto various biointerfaces for intracellular delivery for deeper understanding of stimuli-responsive transformations relevant to controlled drug and biomolecules release and retention

Atomic Force Microscopy and Optical Studies of Organic Thin Films with Hydrogen-Bonded Networks

Brewster angle microscopy and atomic force microscopy were used to characterize the surface morphology of thin films in situ or after transfer onto solid supports. Two acids were studied, differing in carboxylic acid head groups, resulting in significantly different morphological features for thin films formed from these two amphiphiles on a Langmuir trough. Differences in self-assembly and domain sizes were correlated with the formation of hydrogen-bonded networks. The influence of surface hydrophobicity or hydrophilicity during deposition on morphology was also characterized, with spherulitic features appearing in some samples

Plasmonic Library Based on Substrate-Supported Gradiential Plasmonic Arrays

We present a versatile approach to produce macroscopic, substrate-supported arrays of plasmonic nanoparticles with well-defined interparticle spacing and a continuous particle size gradient. The arrays thus present a “plasmonic library” of locally noncoupling plasmonic particles of different sizes, which can serve as a platform for future combinatorial screening of size effects. The structures were prepared by substrate assembly of gold-core/poly(<i>N</i>-isopropylacrylamide)-shell particles and subsequent post-modification. Coupling of the localized surface plasmon resonance (LSPR) could be avoided since the polymer shell separates the encapsulated gold cores. To produce a particle array with a broad range of well-defined but laterally distinguishable particle sizes, the substrate was dip-coated in a growth solution, which resulted in an overgrowth of the gold cores controlled by the local exposure time. The kinetics was quantitatively analyzed and found to be diffusion rate controlled, allowing for precise tuning of particle size by adjusting the withdrawal speed. We determined the kinetics of the overgrowth process, investigated the LSPRs along the gradient by UV–vis extinction spectroscopy, and compared the spectroscopic results to the predictions from Mie theory, indicating the absence of local interparticle coupling. We finally discuss potential applications of these substrate-supported plasmonic particle libraries and perspectives toward extending the concept from size to composition variation and screening of plasmonic coupling effects

Geomechanical stability of the caprock during CO2 sequestration in deep saline aquifers

8 páginas, 5 figuras.Sequestration of carbon dioxide (CO2) in deep saline aquifers has emerged as a mitigation strategy for reducing greenhouse gas emissions to the atmosphere. The large amounts of supercritical CO2 that need to be injected into deep saline aquifers may cause large fluid pressure buildup. The resulting overpressure will produce changes in the effective stress field. This will deform the rock and may promote reactivation of sealed fractures or the creation of new ones in the caprock seal, which could lead to escape paths for CO2. To understand these coupled hydromechanical phenomena, we model an axisymmetric horizontal aquifer-caprock system. We study plastic strain propagation patterns using a viscoplastic approach. Simulations illustrate that plastic strain may propagate through the whole thickness of the caprock if horizontal stress is lower than vertical stress. In contrast, plastic strain concentrates in the contact between the aquifer and the caprock if horizontal stress is larger than vertical stress. Aquifers that present a low-permeability boundary experience an additional fluid pressure increase once the pressure buildup cone reaches the outer boundary. However, fluid pressure does not evolve uniformly in the aquifer. While it increases in the low-permeability boundary, it drops in the vicinity of the injection well because of the lower viscosity of CO2. Thus, caprock stability does not get worse in semi-closed aquifers compared to open aquifers. Overall, the caprock acts as a plate that bends because of pressure buildup, producing a horizontal extension of the upper part of the caprock. This implies a vertical compression of this zone, which may produce settlements instead of uplift in low-permeability (k≤10-18 m2) caprocks at early times of injection.V.V. would like to acknowledge the Spanish Ministry of Science and Innovation (MIC) for financial support through the “Formación de Profesorado Universitario” program. V.V. also wishes to acknowledge the “Colegio de Ingenieros de Caminos, Canales y Puertos – Catalunya” for their financial support. This project has been funded by the Spanish Ministry of Science and Innovation through the project CIUDEN (Ref.: 030102080014), and through the MUSTANG project, from the European Community’s Seventh Framework Programme FP7/2007-2013 under grant agreement nº 227286.Peer reviewe

SERS-based DNT detection

Issued as final reportAgiltron Inc

BioSenSE report

Issued as final reportUniversity of Illinoi

Engineered Bionanocomposites for Biosensing and Bioelectronics

Presented a lecture at the Nano@Tech Meeting on March 10, 2015 at 12 noon in room 102A/B of the Pettit Microelectronics Building.Vladimir V. Tsukruk received his MS degree in physics from the National University of Ukraine, PhD in polymers and DSc in chemistry and polymer science from the National Academy of Sciences of Ukraine. He is currently a Professor at the School of Materials Science and Engineering, Georgia Institute of Technology and a Director of Microanalysis Center. His research in the field of surfaces, interfaces, and molecular assembly of synthetic and natural polymers, nano- and bioinspired hybrid nanomaterials has been recognized by the Humboldt Research Award (2009) and the NSF Special Creativity Award (2006), among others.Runtime: 52:46 minutesVladimir Tsukruk discusses recent results from his research group on designing robust, flexible, actuating, and responsive nanoscale multilayered hybrid nanomaterials for biosensing and bioelectronic applications. Ultrathin shells from synthetic and natural materials are assembled in order to conduct surface modification and protection of model microparticles, cells and cell assemblies. Microcapsules designed here are formed at interfaces from various linear and branched synthetic and biological macromolecules and graphene oxide assembled via hydrogen-bonding, ion pairing, and hydrophobic-hydrophobic interactions and tunable by temperature, pH or illumination of solutions. Various means are further exploited to transfer the LbL shells on various bacterial cells and place them in larger encapsulated cell arrays for bio-colometric detection. Ultra strong laminated bionanocomposites from silk and graphene oxide components with unique interphase morphology were found to possess extremely high elastic modulus and toughness, as well conductive patterning with localized electrochemical reduction

NIRT: Bioinspired nanomembranes for multifunctional sensors

Issued as final reportNational Science Foundation (U.S.

Liquid-crystalline processing of highly oriented carbon nanotube arrays for thin-film transistors

We introduce a simple solution-based method for the fabrication of highly oriented carbon nanotube (CNT) arrays to be used for thin-film transistors. We exploit the liquid-crystalline behavior of a CNT solution near the receding contact line during tilted-drop casting and produced long-range nematic-like ordering of carbon nanotube stripes caused by confined micropatterned geometry. We further demonstrate that the performance of thin-film transistors based on these densely packed and uniformly oriented CNT arrays is largely improved compared to random CNTs. This approach has great potential in low-cost, large-scale processing of high-performance electronic devices based on high-density oriented CNT films with record electrical characteristics such as high conductance, low resistivity, and high career mobility.close878