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May 2015
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1

  1. Center for Functional Nanomaterials Seminar

    10 am, CFN, Bldg. 735, Conf. Rm. A - 1st floor

    Hosted by: Oleg Gang

    Center for Functional Nanomaterials Seminar Programmed Self-Assembly of Complex DNA Nanostructures and Applications in DNA Nanofabrication Cheng Tian Department of Chemistry, University of Pittsburgh Friday, May 1, 2015 10:00 a.m. Bldg. 735 " Conference Room A This presentation focuses on the design and synthesis of complex DNA nanostructures and their applications in DNA nanofabrication. DNA has served as a superb building block to self-assemble into a wide range of predictable and robust nanostructures with the bottom-up method. Synthesized DNA nanostructures have been applied as templates for the organization of guest molecules and molecular lithography, biosensors for the genetic diagnosis and environmental detection, nanocarriers for the drug delivery therapy, and logic units for the DNA computation. My research focuses on the development of novel DNA building blocks, assembly strategies and simplified design systems to design and synthesize DNA nanostructures with a higher diversity and complexity, and applied DNA nanostructures as scaffolds to organize guest molecules and as templates for the nanopatterning.

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15

  1. Center for Functional Nanomaterials Seminar

    11 am, CFN - Bldg. 735 First Floor Conference Room A

    Hosted by: Matthew Sfeir

    Solar energy can be directly harvested to power thermodynamically uphill reactions that produce energetic chemicals, promising a large-scale energy storage and redistribution solution. To enable these reactions, we need materials that can absorb light, separate charges, and catalyze specific chemistries. The materials should be made of earth-abundant elements to allow for large-scale implementations. They also need to be resistant against photo corrosion. To date, a low-cost, long-lasting material that can produce solar fuels with an economically meaningful efficiency remains elusive. In this talk, we present our efforts aimed at understanding what limits the development of this important field. Within the context of photoanode and photocathode, we show how the photoelectrode properties are changed by introducing material components designed for improving charge transport, surface potential accumulation, and interface kinetics, respectively. We also demonstrate that highly complex organic molecules can be produced by photoreduction of CO2, in a fashion similar to the dark reactions in natural photosynthesis. Our results highlight the importance of separately understanding thermodynamic and kinetic factors in complex systems such as that for solar fuel production. Detailed knowledge generated by our research contributes to the goal of realizing low-cost, high-efficiency artificial photosynthesis.

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20

  1. Center for Functional Nanomaterials Seminar

    10 am, Center for Functional Nanomaterials, Bldg 735, Con

    Hosted by: Chuck Black

    The directed self-assembly (DSA) of block copolymers (BCPs) has attracted significant interest as an extension to lithography by enhancing resolution and improving dimensional uniformity. Typically, DSA offers a limited set of dense and highly periodic patterns; on the other hand, integrated circuit fabrication require more complex patterns customized according to design. This talk will discuss recent advances toward customizable nanoscale fabrication based on the DSA of lamellae-forming polystyrene-block-poly (methyl methacrylate) thin films using underlying, partially inorganic chemical guiding patterns. As the foundation of these advances, a new route to create customized BCP patterns is introduced by encoding chemical patterns with inorganic guiding lines and non-guiding "masking" features. Subsequent DSA and pattern transfer results in line-space gratings with gaps between lines and trim across lines dictated by the placement of guiding lines and masking features, respectively. Thermodynamic analysis reveals the rules governing chemical pattern and process design in order to achieve defect-free BCP assembly with pattern customization over large areas. Furthermore, designing these "hybrid" organic-inorganic chemical patterns in an opposite pattern tone with guiding trenches in place of guiding lines affords greater design flexibility and illustrates a path to integrate BCP DSA into high-volume integrated circuit manufacturing. These self-aligned, bidirectional customization schemes create new opportunities for high-resolution, circuit-relevant patterning using DSA.

21

  1. Center for Functional Nanomaterials Seminar

    11 am, CFN - Bldg. 735, Conf. Rm. A - 1st floor

    Hosted by: Deyu Lu

    Center for Functional Nanomaterials Seminar David Prendergast Dynamics in materials evident through first-principles interpretation of X-ray spectroscopy The Molecular Foundry, Lawrence Berkeley National Laboratory Thursday, May 21, 2015 11:00 a.m. Bldg. 735 " Conf. Rm. A The intrinsic ultrafast time scale of core-level excitations permits the use of X-ray spectroscopy to sample energy-relevant dynamics in materials. With the advent of X-ray free electron lasers, and even table-top X-ray sources, pump-probe measurements allow us to drive particular excitations externally and follow a given system response. Examples will be presented relevant to solar harvesting and the fundamental interactions that thermalize excited electron-hole distributions. Additionally, the intrinsic dynamics of materials around their thermodynamic equilibria are continually being sampled using typical synchrotron X-ray sources. In fact, without sampling the thermodynamic distribution, simulated spectra may lack particular features related to defect populations, interconversion of chemical species, momentary broken symmetry, etc. Through a combination of theoretical predictions and interpretation of experiment, it is possible to begin to disentangle the wealth of information in X-ray spectroscopy. Examples will be given from recent work in the context of electrochemical energy storage. Host: Deyu Lu Joann Tesoriero Center for Functional Nanomaterials P.O. Box 5000 Upton, NY 11973 631-344-7791 631-344-7769 tesoriero@bnl.gov

  2. Center for Functional Nanomaterials Seminar

    1:30 pm, CFN, Bldg. 735 - conf. rm. A

    Hosted by: Alexei Tkachenko

    Center for Functional Nanomaterials Seminar Multiscale Modeling of Self-assembly of Nanostructures, Nanomedicines, and Functionalized Graphenes Niladri Patra Department of Chemical Engineering, Massachusetts Institute of Technology Thursday, May 21, 2015 1:30 p.m. Bldg. 735 " Conference Room A We study by multiscale computational methods the self-assembly of complex nanostructures from atomic and molecular components. First, we demonstrate by classical molecular dynamics (MD) simulations how water nanodroplets and carbon nanotubes (CNTs) can activate and guide bending, folding, sliding, and rolling of planar graphene nanostructures. Next, we show by coarse-grained MD simulations that hydrated lipid micelles of preferred sizes and amounts of filling with hydrophobic molecules can be self-assembled on the surfaces of CNTs. Then, we model in collaboration with experimentalists nanomedicines based on self-assembled micelles, formed by highly PEGylated linear and branched (dendron-based) polymers. We also investigate the quantum dynamics of ion binding to graphene nanostructures using quantum MD simulations. We show that anions are either physisorbed onto the nanostructures or covalently bound at their selected regions, depending on the initial conditions, while cations only physisorb onto the nanostructures. Then, we describe the nucleation of long chains, large clusters, and complex cage structures in carbon and hydrogen rich interstellar gas phases by reactive MD simulations. Finally, we show how the H-atom of hydroxyl group of the catecholate ion (inhibitor) flipping changes the active site structure of the enzyme and the presence of double potential well in catechol-o-methyl transferase inhibitor complex by free energy calculations. Host: Alexei Tkachenko

  3. Center for Functional Nanomaterials Seminar

    1:30 pm, CFN, Bldg. 735 - conf. rm. A

    Hosted by: Alexei Tkachenko

    Center for Functional Nanomaterials Seminar Multiscale Modeling of Self-assembly of Nanostructures, Nanomedicines, and Functionalized Graphenes Niladri Patra Department of Chemical Engineering, Massachusetts Institute of Technology Thursday, May 21, 2015 1:30 p.m. Bldg. 735 " Conference Room A We study by multiscale computational methods the self-assembly of complex nanostructures from atomic and molecular components. First, we demonstrate by classical molecular dynamics (MD) simulations how water nanodroplets and carbon nanotubes (CNTs) can activate and guide bending, folding, sliding, and rolling of planar graphene nanostructures. Next, we show by coarse-grained MD simulations that hydrated lipid micelles of preferred sizes and amounts of filling with hydrophobic molecules can be self-assembled on the surfaces of CNTs. We also show that porous carbon nanotubes can be used in a selective molecular absorption, transport, and separation. Then, we model in collaboration with experimentalists nanomedicines based on self-assembled micelles, formed by highly PEGylated linear and branched (dendron-based) polymers. We also investigate the quantum dynamics of ion binding to graphene nanostructures using quantum MD simulations. We show that anions are either physisorbed onto the nanostructures or covalently bound at their selected regions, depending on the initial conditions, while cations only physisorb onto the nanostructures. Finally, we describe the nucleation of long chains, large clusters, and complex cage structures in carbon and hydrogen rich interstellar gas phases by reactive MD simulations. Host: Alexei Tkachenko

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26

  1. MAY

    26

    Tuesday

    Center for Functional Nanomaterials Seminar

    10 am, Bldg 735, Conference Room A

    Tuesday, May 26, 2015, 10:00 am

    Hosted by: Chuck Black

    Directed self-assembly (DSA) of block copolymers (bcp) is a leading strategy to pattern at sub-lithographic resolution in the technology roadmap for semiconductors, and is the only known solution to fabricate nano-imprint templates for the production of bit pattern media. Integration of DSA with traditional top-down processes is a principal challenge, particularly with respect to the process used to anneal the polymer thin films. Thermal annealing is the most developed method, resembling track processing of photoresists on hotplates, and has been used in demonstrations of DSA closest to commercial applications. Solvent annealing is a more complicated process and is less manufacturing friendly, but offers advantages in terms of diversity of materials and domain structures that can be assembled, and has resulted in the DSA of the highest resolution features demonstrated to date. Here we report a DSA process based on lithographically defined chemical templates and solvent annealing to pattern and pattern transfer 8 nm features on a 16 nm pitch with precise controllable variation in pattern dimensions (± 5 percent) required for arranging bits of patterned media in circular tracks. Key innovations include: 1) implementing a quasi-equilibrium process using solvents in which the polymer assembles in the solvated state, 2) delineating and taking advantage of the thermodynamic properties of tri-block copolymer/solvent mixtures to allow for sub 10 nm features, and 3) optimizing a pattern transfer technology using reactive vapor phase precursors to selectively transform block copolymer domains into inorganic hard masks.

27

  1. MAY

    27

    Wednesday

    Center for Functional Nanomaterials Seminar

    10 am, CFN, Bldg. 735, conference A, 1st floor

    Wednesday, May 27, 2015, 10:00 am

    Hosted by: Anibal Boscoboinik

    Center for Functional Nanomaterials Seminar Effect of pH on polyelectrolyte multilayer formation and growth factor release for orthopedic applications Amy M. Peterson Leonard P. Kinnicutt Assistant Professor Department of Chemical Engineering Worcester Polytechnic Institute Wednesday, May 27, 2015 10:00 a.m. Bldg. 735 " Conference Room A Abstract: Because of its strength, durability, and biocompatibility, titanium is a widely used material for orthopedic implants. However, its insufficient integration with the surrounding bone tissue regularly leads to implant loosening and premature implant revision. A promising solution to improve integration is to modify the implant surface chemistry and topography by coating it with a protein-eluting polyelectrolyte multilayer (PEM) coating. Bone morphogenetic protein 2 (BMP-2), a potent osteoconductive growth factor, was adsorbed onto the surface of anodized titanium, and PEM coatings prepared from solutions of poly-L-histidine (PLH) and poly(methacrylic acid) (PMAA) were built on the BMP-2 layer. The effect of the solutions' pH during the deposition process was investigated. High levels of BMP-2 released over several months were achieved. Approximately 2 μg/cm² of BMP-2 were initially adsorbed on the anodized titanium and a deposition pH-dependent release behavior was observed under physiological conditions. More stable coatings were assembled at pH values corresponding to the closed state of the polyelectrolyte complex. Three different diffusion regimes could be determined from the release profiles: an initial burst release, a sustained release regime and a depletion regime. Mass adsorption monitoring using quartz crystal microbalance with dissipation monitoring (QCM-D) showed that PLH was adsorbed in greater quantities than PMAA

28

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31

  1. MAY

    31

    Sunday

    CFN Proposal Deadline

    11:45 pm, CFN

    Sunday, May 31, 2015, 11:45 pm

  1. MAY

    26

    Tuesday

    Center for Functional Nanomaterials Seminar

    "Directed self-assembly of ABA triblock copolymer on chemical pattern via solvent annealing for sub-10nm fabrication"

    Presented by Shisheng Xiong, Institute for Molecular Engineering, the University of Chicago, and Argonne National Labs

    10 am, Bldg 735, Conference Room A

    Tuesday, May 26, 2015, 10:00 am

    Hosted by: Chuck Black

    Directed self-assembly (DSA) of block copolymers (bcp) is a leading strategy to pattern at sub-lithographic resolution in the technology roadmap for semiconductors, and is the only known solution to fabricate nano-imprint templates for the production of bit pattern media. Integration of DSA with traditional top-down processes is a principal challenge, particularly with respect to the process used to anneal the polymer thin films. Thermal annealing is the most developed method, resembling track processing of photoresists on hotplates, and has been used in demonstrations of DSA closest to commercial applications. Solvent annealing is a more complicated process and is less manufacturing friendly, but offers advantages in terms of diversity of materials and domain structures that can be assembled, and has resulted in the DSA of the highest resolution features demonstrated to date. Here we report a DSA process based on lithographically defined chemical templates and solvent annealing to pattern and pattern transfer 8 nm features on a 16 nm pitch with precise controllable variation in pattern dimensions (± 5 percent) required for arranging bits of patterned media in circular tracks. Key innovations include: 1) implementing a quasi-equilibrium process using solvents in which the polymer assembles in the solvated state, 2) delineating and taking advantage of the thermodynamic properties of tri-block copolymer/solvent mixtures to allow for sub 10 nm features, and 3) optimizing a pattern transfer technology using reactive vapor phase precursors to selectively transform block copolymer domains into inorganic hard masks.

  2. MAY

    27

    Wednesday

    Center for Functional Nanomaterials Seminar

    "Effect of pH on polyelectrolyte multilayer formation and growth factor release for orthopedic applications"

    Presented by Amy M. Peterson, Worcester Polytechnic Institute

    10 am, CFN, Bldg. 735, conference A, 1st floor

    Wednesday, May 27, 2015, 10:00 am

    Hosted by: Anibal Boscoboinik

    Center for Functional Nanomaterials Seminar Effect of pH on polyelectrolyte multilayer formation and growth factor release for orthopedic applications Amy M. Peterson Leonard P. Kinnicutt Assistant Professor Department of Chemical Engineering Worcester Polytechnic Institute Wednesday, May 27, 2015 10:00 a.m. Bldg. 735 " Conference Room A Abstract: Because of its strength, durability, and biocompatibility, titanium is a widely used material for orthopedic implants. However, its insufficient integration with the surrounding bone tissue regularly leads to implant loosening and premature implant revision. A promising solution to improve integration is to modify the implant surface chemistry and topography by coating it with a protein-eluting polyelectrolyte multilayer (PEM) coating. Bone morphogenetic protein 2 (BMP-2), a potent osteoconductive growth factor, was adsorbed onto the surface of anodized titanium, and PEM coatings prepared from solutions of poly-L-histidine (PLH) and poly(methacrylic acid) (PMAA) were built on the BMP-2 layer. The effect of the solutions' pH during the deposition process was investigated. High levels of BMP-2 released over several months were achieved. Approximately 2 μg/cm² of BMP-2 were initially adsorbed on the anodized titanium and a deposition pH-dependent release behavior was observed under physiological conditions. More stable coatings were assembled at pH values corresponding to the closed state of the polyelectrolyte complex. Three different diffusion regimes could be determined from the release profiles: an initial burst release, a sustained release regime and a depletion regime. Mass adsorption monitoring using quartz crystal microbalance with dissipation monitoring (QCM-D) showed that PLH was adsorbed in greater quantities than PMAA

  3. MAY

    31

    Sunday

    CFN Proposal Deadline

    "CFN Proposal Deadline for September-December Cycle 2015"

    11:45 pm, CFN

    Sunday, May 31, 2015, 11:45 pm

  4. SEP

    30

    Wednesday

    CFN Proposal Deadline

    "CFN Proposal Deadline for January-April Cycle 2016"

    11:45 pm, CFN

    Wednesday, September 30, 2015, 11:45 pm