J. Biener

Bio: J. Biener is an academic researcher from Lawrence Livermore National Laboratory. The author has contributed to research in topics: Inertial confinement fusion & National Ignition Facility. The author has an hindex of 8, co-authored 11 publications receiving 898 citations.

Advanced carbon aerogels for energy applications

Abstract: Carbon aerogels are a unique class of high-surface-area materials derived by sol–gel chemistry. Their high mass-specific surface area and electrical conductivity, environmental compatibility and chemical inertness make them very promising materials for many energy related applications, specifically in view of recent developments in controlling their morphology. In this perspective we will review the synthesis of monolithic resorcinol–formaldehyde based carbon aerogels with hierarchical porosities for energy applications, including carbon nanotube and graphene composite carbon aerogels, as well as their functionalization by surface engineering. Applications that we will discuss include hydrogen and electrical energy storage, desalination and catalysis.

Ramp compression of diamond to five terapascals

Abstract: The recent discovery of more than a thousand planets outside our Solar System, together with the significant push to achieve inertially confined fusion in the laboratory, has prompted a renewed interest in how dense matter behaves at millions to billions of atmospheres of pressure. The theoretical description of such electron-degenerate matter has matured since the early quantum statistical model of Thomas and Fermi, and now suggests that new complexities can emerge at pressures where core electrons (not only valence electrons) influence the structure and bonding of matter. Recent developments in shock-free dynamic (ramp) compression now allow laboratory access to this dense matter regime. Here we describe ramp-compression measurements for diamond, achieving 3.7-fold compression at a peak pressure of 5 terapascals (equivalent to 50 million atmospheres). These equation-of-state data can now be compared to first-principles density functional calculations and theories long used to describe matter present in the interiors of giant planets, in stars, and in inertial-confinement fusion experiments. Our data also provide new constraints on mass-radius relationships for carbon-rich planets.

Diamond spheres for inertial confinement fusion

Abstract: The National Ignition Facility (NIF) will allow scientists to prove the feasibility of inertial confinement fusion (ICF). The success of ICF experiments at NIF will critically depend on the availability of robust targets. Guided by computer simulations, we generated a new target design that takes advantage of the extreme atomic density of synthetic diamond, and developed a process that allows us to produce large quantities of these ultrahigh precision diamond targets via a low-cost batch process. Computer simulations were used to assess the performance and the robustness of these diamond targets. The results demonstrate that diamond has the potential to outperform other target materials in terms of energy efficiency and implosion stability, thus making successful ignition more likely.

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility.

Abstract: The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12 30) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

Diamond Ablators for Inertial Confinement Fusion

Abstract: Diamond has a unique combination of physical properties for the inertial confinement fusion ablator application, such as appropriate optical properties, high atomic density, high yield strength, an...

Complex Hydrides for Hydrogen Storage

Abstract: Note: Times Cited: 875 Reference EPFL-ARTICLE-206025doi:10.1021/cr0501846View record in Web of Science URL: ://WOS:000249839900009 Record created on 2015-03-03, modified on 2017-05-12

Design and Preparation of Porous Polymers

Abstract: Dingcai Wu,*,† Fei Xu,† Bin Sun,† Ruowen Fu,† Hongkun He,‡ and Krzysztof Matyjaszewski*,‡ †Materials Science Institute, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, People's Republic of China ‡Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States

Hierarchically porous carbon derived from polymers and biomass: effect of interconnected pores on energy applications

Abstract: Hierarchically porous carbons (HPCs) with 1D to 3D network are attracting vast interest due to their potential technological application profile ranging from electrochemical capacitors, lithium ion batteries, solar cells, hydrogen storage systems, photonic material, fuel cells, sorbent for toxic gas separation and so on. Natural raw-materials such as biomass-biopolymer derived hierarchical nanostructured carbons are especially attractive for their uniform pore dimensions which can be adjustable over a wide range of length scales. Good electrical conductivity, high surface area, and excellent chemical stability are unique physicochemical properties which are responsible for micro/nanostructured porous carbon to be highly trusted candidate for emerging nanotechnologies. This review focuses on the ‘out-of-the-box’ synthetic techniques capable of deriving HPC with superior application profiles. The article presents the promising scope of accessing HPCs from (1) hard-templating, soft-templating, and non-templating routes, (2) biopolymers with a major focus on non-templating strategies. Subsequently, emerging strategies of hetero-atom doping in porous carbon nanostructures are discussed. The review will highlight the contribution of synergistic effect of macro–meso–micropores on a range of emerging applications such as CO2 capture, carbon photonic crystal sensors, Li–S batteries, and supercapacitor. Mechanism of ion transport and buffering, electrical double layer enhancement have been discussed in the context of pore structure and shapes. We will also show the differences of HPC and ordered mesoporous carbon (OMC) in terms of their synthesis strategies and choices of template for self-assembly. How the remarkable mechanical strength of the HPCs can be achieved by selecting self-assembling template, whereas collapse of mesostructure via decomposition of framework occurs due to poor thermal stability or high N-content of the carbon source will be discussed.

Three dimensional macroporous architectures and aerogels built of carbon nanotubes and/or graphene: synthesis and applications

Abstract: Carbon nanotubes and graphene are some of the most intensively explored carbon allotropes in materials science. This interest mainly resides in their unique properties with electrical conductivities as high as 104 S cm−1, thermal conductivities as high as 5000 W m−1 K and superior mechanical properties with elastic moduli on the order of 1 TPa for both of them. The possibility to translate the individual properties of these monodimensional (e.g. carbon nanotubes) and bidimensional (e.g. graphene) building units into two-dimensional free-standing thick and thin films has paved the way for using these allotropes in a number of applications (including photocatalysis, electrochemistry, electronics and optoelectronics, among others) as well as for the preparation of biological and chemical sensors. More recently and while recognizing the tremendous interest of these two-dimensional structures, researchers are noticing that the performance of certain devices can experience a significant enhancement by the use of three-dimensional architectures and/or aerogels because of the increase of active material per projected area. This is obviously the case as long as the nanometre-sized building units remain accessible so that the concept of hierarchical three-dimensional organization is critical to guarantee the mass transport and, as consequence, performance enhancement. Thus, this review aims to describe the different synthetic processes used for preparation of these three-dimensional architectures and/or aerogels containing either any or both allotropes, and the different fields of application in which the particular structure of these materials provided a significant enhancement in the efficacy as compared to their two-dimensional analogues or even opened the path to novel applications. The unprecedented compilation of information from both CNT- and graphene-based three-dimensional architectures and/or aerogels in a single revision is also of interest because it allows a straightforward comparison between the particular features provided by each allotrope.

Density functional theory: Its origins, rise to prominence, and future

Abstract: Density functional theory has been spectacularly successful in physics, chemistry, and related fields, and it keeps finding new applications. This paper gives an overview of the history of the method and its many applications since it gained wide acceptance, as well as a discussion of its likely future.