scholarly journals Recent Advances in Sequential Infiltration Synthesis (SIS) of Block Copolymers (BCPs)

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 994
Author(s):  
Eleonora Cara ◽  
Irdi Murataj ◽  
Gianluca Milano ◽  
Natascia De Leo ◽  
Luca Boarino ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Large Scale ◽  
Inorganic Materials ◽  
Ex Situ ◽  
Selective Incorporation ◽  
Microelectronics Industry ◽  
Self Assembled ◽  
Definition Of ◽  
Synthetic Approaches

In the continuous downscaling of device features, the microelectronics industry is facing the intrinsic limits of conventional lithographic techniques. The development of new synthetic approaches for large-scale nanopatterned materials with enhanced performances is therefore required in the pursuit of the fabrication of next-generation devices. Self-assembled materials as block copolymers (BCPs) provide great control on the definition of nanopatterns, promising to be ideal candidates as templates for the selective incorporation of a variety of inorganic materials when combined with sequential infiltration synthesis (SIS). In this review, we report the latest advances in nanostructured inorganic materials synthesized by infiltration of self-assembled BCPs. We report a comprehensive description of the chemical and physical characterization techniques used for in situ studies of the process mechanism and ex situ measurements of the resulting properties of infiltrated polymers. Finally, emerging optical and electrical properties of such materials are discussed.

scholarly journals Biopolymer colloids for controlling and templating inorganic synthesis

2014 ◽  
Vol 5 ◽  
pp. 2129-2138 ◽  
Author(s):  
Laura C Preiss ◽  
Katharina Landfester ◽  
Rafael Muñoz-Espí
Keyword(s):  
Nucleation And Growth ◽  
Inorganic Materials ◽  
The Other ◽  
Shell Structures ◽  
Ex Situ ◽  
Inorganic Synthesis ◽  
Wide Range ◽  
Synthetic Approaches ◽  
Soft Templates

Biopolymers and biopolymer colloids can act as controlling agents and templates not only in many processes in nature, but also in a wide range of synthetic approaches. Inorganic materials can be either synthesized ex situ and later incorporated into a biopolymer structuring matrix or grown in situ in the presence of biopolymers. In this review, we focus mainly on the latter case and distinguish between the following possibilities: (i) biopolymers as controlling agents of nucleation and growth of inorganic materials; (ii) biopolymers as supports, either as molecular supports or as carrier particles acting as cores of core–shell structures; and (iii) so-called “soft templates”, which include on one hand stabilized droplets, micelles, and vesicles, and on the other hand continuous scaffolds generated by gelling biopolymers.

scholarly journals Three-Dimensional Self-assembled Hairball-Like VS4 as High-Capacity Anodes for Sodium-Ion Batteries

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuangshuang Ding ◽  
Bingxin Zhou ◽  
Changmiao Chen ◽  
Zhao Huang ◽  
Pengchao Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
High Capacity ◽  
Sodium Ion ◽  
Ex Situ ◽  
Sodium Ion Batteries ◽  
High Discharge Capacity ◽  
Reversible Transformation ◽  
Self Assembled ◽  
Consistent Performance

AbstractSodium-ion batteries (SIBs) are considered to be attractive candidates for large-scale energy storage systems because of their rich earth abundance and consistent performance. However, there are still challenges in developing desirable anode materials that can accommodate rapid and stable insertion/extraction of Na+ and can exhibit excellent electrochemical performance. Herein, the self-assembled hairball-like VS4 as anodes of SIBs exhibits high discharge capacity (660 and 589 mAh g−1 at 1 and 3 A g−1, respectively) and excellent rate property (about 100% retention at 10 and 20 A g−1 after 1000 cycles) at room temperature. Moreover, the VS4 can also exhibit 591 mAh g−1 at 1 A g−1 after 600 cycles at 0 °C. An unlike traditional mechanism of VS4 for Na+ storage was proposed according to the dates of ex situ characterization, cyclic voltammetry, and electrochemical kinetic analysis. The capacities of the final stabilization stage are provided by the reactions of reversible transformation between Na2S and S, which were considered the reaction mechanisms of Na–S batteries. This work can provide a basis for the synthesis and application of sulfur-rich compounds in fields of batteries, semiconductor devices, and catalysts.

scholarly journals The decline and conservation management of the threatened endemic palms of the Mascarene Islands

Oryx ◽  
2002 ◽  
Vol 36 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Mike Maunder ◽  
Wayne Page ◽  
John Mauremootoo ◽  
Richard Payendee ◽  
Yousoof Mungroo ◽  
...  
Keyword(s):  
Large Scale ◽  
Conservation Management ◽  
Conservation Status ◽  
Iucn Red List ◽  
Ex Situ ◽  
Population Fragmentation ◽  
Wild Populations ◽  
Mascarene Islands

Abstract The conservation status of the five genera and 11 species of palm endemic to the Mascarene Islands (Mauritius, La Réunion and Rodriques) are reviewed. All species are threatened with extinction; nine taxa are classified as Critically Endangered and four as Endangered on the 2000 IUCN Red List. Two taxa survive as single wild specimens (Hyophorbe amaricaulis and Dictyosperma album var. conjugatum); an additional seven taxa have wild populations of 100 or fewer. Although the historical phase of large-scale forest clearance has passed, the remaining palm populations in the Mascarenes are under threat from the effects of population fragmentation, invasive plants and animals, and high levels of seed predation that prevent natural regeneration. The advantages of in situ management for the recovery of these palm populations are discussed. Without a long-term conservation programme, utilising both in situ and ex situ management, extinction of wild populations will occur.

scholarly journals A framework for selectively breeding corals for assisted evolution

2021 ◽  
Author(s):  
Adriana Humanes ◽  
John Bythell ◽  
Elizabeth Beauchamp ◽  
Mitch Carl ◽  
Jamie Craggs ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Selective Breeding ◽  
Coral Cover ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Acropora Digitifera ◽  
Interdisciplinary Approaches ◽  
The Face

AbstractCoral cover on tropical reefs has declined during the last three decades due to the combined effects of climate change, destructive fishing, pollution, and land use change. Drastic reductions in greenhouse gas emissions combined with effective coastal management and conservation strategies are essential to slow this decline. Innovative approaches, such as selective breeding for adaptive traits combined with large-scale sexual propagation, are being developed with the aim of pre-adapting reefs to increased ocean warming. However, there are still major gaps in our understanding of the technical and methodological constraints to producing corals for such restoration interventions. Here we propose a framework for selectively breeding corals and rearing them from eggs to 2.5-year old colonies using the coral Acropora digitifera as a model species. We present methods for choosing colonies for selective crossing, enhancing early survivorship in ex situ and in situ nurseries, and outplanting and monitoring colonies on natal reefs. We used a short-term (7-day) temperature stress assay to select parental colonies based on heat tolerance of excised branches. From six parental colonies, we produced 12 distinct crosses, and compared survivorship and growth of colonies transferred to in situ nurseries or outplanted to the reef at different ages. We demonstrate that selectively breeding and rearing coral colonies is technically feasible at small scales and could be upscaled as part of restorative assisted evolution initiatives. Nonetheless, there are still challenges to overcome before selective breeding can be implemented as a viable conservation tool, especially at the post-settlement and outplanting phases. Although interdisciplinary approaches will be needed to overcome many of the challenges identified in this study, selective breeding has the potential to be a viable tool within reef managers’ toolbox to support the persistence of selected reefs in the face of climate change.

In Situ and Ex Situ Microscopic Study of Propylene Polymerization With Heterogeneous Mgcl2-Supported Ziegler-Natta Catalysts

2000 ◽  
Vol 6 (S2) ◽  
pp. 33-34
Author(s):  
V. Oleshko ◽  
P. Crozier ◽  
R. Cantrell ◽  
A. Westwood
Keyword(s):  
Large Scale ◽  
Heterogeneous Catalysts ◽  
High Surface ◽  
Light And Electron Microscopy ◽  
High Surface Area ◽  
Propylene Polymerization ◽  
Ex Situ ◽  
Co Catalysts ◽  
Ziegler Natta Catalysts

The large-scale commercial production of polyolefins by catalytic Ziegler-Natta polymerization have stimulated the development of the third, fourth and fifth generation heterogeneous catalysts comprising high surface area defective MgCl2 with TiCl4, electron donors, and AlR3-co-catalysts. In spite of intensive research over the years, the present level of understanding of the catalysts is still incomplete because of their complex composition leading to a multitude of local active site environments. The aim of this work is to provide a new insight into the process via in situ video microscopy of gas phase propylene polymerization over MgCl2-supported Ziegler-Natta catalysts combined with ex situ characterization by light and electron microscopy techniques (SEM, TEM, HRTEM, STEM, PEELS and windowless EDX). Procedures for catalyst synthesis are described elsewhere. The catalysts were stored in a dry box under a He atmosphere (<lppm H2O/O2). Samples were transferred to specimen holders in the dry box and then transferred into the microscopes under high purge N2 conditions to prevent poisoning of the catalysts by air and moisture.

scholarly journals Ex-Situ Evaluation of Commercial Polymer Membranes for Vanadium Redox Flow Batteries (VRFBs)

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 926
Author(s):  
Nana Zhao ◽  
Harry Riley ◽  
Chaojie Song ◽  
Zhengming Jiang ◽  
Keh-Chyun Tsay ◽  
...  
Keyword(s):  
Large Scale ◽  
Polymer Membranes ◽  
Ex Situ ◽  
Anion Exchange Membranes ◽  
In Situ Testing ◽  
Ionic Charge ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Vanadium Redox

Polymer membranes play a vital role in vanadium redox flow batteries (VRFBs), acting as a separator between the two compartments, an electronic insulator for maintaining electrical neutrality of the cell, and an ionic conductor for allowing the transport of ionic charge carriers. It is a major influencer of VRFB performance, but also identified as one of the major factors limiting the large-scale implementation of VRFB technology in energy storage applications due to its cost and durability. In this work, five (5) high-priority characteristics of membranes related to VRFB performance were selected as major considerable factors for membrane screening before in-situ testing. Eight (8) state-of-the-art of commercially available ion exchange membranes (IEMs) were specifically selected, evaluated and compared by a set of ex-situ assessment approaches to determine the possibility of the membranes applied for VRFB. The results recommend perfluorosulfonic acid (PFSA) membranes and hydrocarbon anion exchange membranes (AEMs) as the candidates for further in-situ testing, while one hydrocarbon cation exchange membrane (CEM) is not recommended for VRFB application due to its relatively high VO2+ ion crossover and low mechanical stability during/after the chemical stability test. This work could provide VRFB researchers and industry a valuable reference for selecting the polymer membrane materials before VRFB in-situ testing.

scholarly journals Augmented Virtuality for Coastal Management: An Holistic Use of In-Situ and Remote Sensing for Large Scale Definition of Coastal Dynamics

2017 ◽  
Author(s):  
Sandro Bartolini ◽  
Alessandro Mecocci ◽  
Alessandro Pozzebon ◽  
Claudia Zoppetti ◽  
Duccio Bertoni ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Data Acquisition ◽  
Large Scale ◽  
Heterogeneous Data ◽  
Coastal Dynamics ◽  
Augmented Virtuality ◽  
Sensing Systems ◽  
In Situ Sensing ◽  
Definition Of

In this paper the authors describe the architecture of a multidisciplinary data acquisition and visualization platform devoted to the management of coastal environments. The platform integrates heterogeneous data acquisition sub-systems that can be roughly divided in two main categories: remote sensing systems and in-situ sensing systems. Remote sensing solutions include aerial and underwater remote data acquisition while in-situ sensing solutions include the use of RFID tracers, Wireless Sensor Networks and imaging techniques. All the data collected by these subsystems are stored, integrated and fused on a single platform that is also in charge of data visualization. This last task is carried out according to the paradigm of Augmented Virtuality which foresees the augmentation of a virtually reconstructed environment with data collected in the real world. The described solution proposes a novel holistic approach where different disciplines concur, with different data acquisition techniques, to a large scale definition of coastal dynamics, in order to better describe and face the coastal erosion phenomenon. The overall framework has been conceived by the so-called Team COSTE, a joint research team between the Universities of Pisa, Siena and Florence.

scholarly journals On the structure of the extra-tropical transition layer from in-situ observations

2012 ◽  
Vol 12 (10) ◽  
pp. 28033-28068
Author(s):  
I. Pisso ◽  
K. S. Law ◽  
F. Fierli ◽  
P. H. Haynes ◽  
P. Hoor ◽  
...  
Keyword(s):  
Transition Layer ◽  
Large Scale ◽  
Trace Gases ◽  
Potential Temperature ◽  
Local Maximum ◽  
Upper Limit ◽  
Relative Coordinates ◽  
In Situ Observations ◽  
Definition Of

Abstract. In-situ observations of atmospheric tracers from multiple measurement campaigns over the period 1994–2007 were combined to investigate the Extra-tropical Transition Layer (ExTL) region and the properties of large scale meridional transport. We used potential temperature, equivalent latitude and distance relative to the local dynamical tropopause as vertical coordinates to highlight the behaviour of trace gases in the tropopause region. Vertical coordinates based on constant PV surfaces allowed us to relate the dynamical definition of the tropopause with trace gases distributions and vertical gradients and hence analyse its latitudinal dependence and seasonal variability. Analysis of the available data provides a working definition of the upper limit of the ExTL based on the upper limit of the region of high vertical CO gradient in PV relative coordinates. A secondary local maximum in vertical O3 gradient can be used a proxy for the lower limit, although it is less clearly defined than that of CO. The sloping isopleths of CO and O3 mixing ratios and the CO mixing ratio gradient are consistent with isopleths in purely dynamical diagnostics such as χ30 d, the proportion of air masses in contact with the PBL within one month and underline the differences between the PV based and chemical tropopauses. The use of tropopause relative coordinates allows different seasons to be analysed together to produce climatological means. The weak dependence of dynamical diagnostics of transport on the absolute values of tracer concentrations makes them a suitable process-oriented tool to evaluate global chemical models and make Lagrangian comparisons.

scholarly journals Saint Venant and Navier-Stokes Models for Tsunami Simulations

2018 ◽  
Author(s):  
Camille Journeau ◽  
Kévin Pons ◽  
Richard Marcer
Keyword(s):  
Large Scale ◽  
Large Range ◽  
Navier Stokes ◽  
Test Cases ◽  
Tsunami Propagation ◽  
In Situ Data ◽  
Impact Modelling ◽  
Case Simulation ◽  
Definition Of

Into the frame of the French TANDEM project (Tsunamis in the Atlantic and the English ChaNnel: Definition of the Effects through numerical Modelling) Principia has been working on the development and qualification of two in-house CFD software&rsquo;s: the 2D EOLE-SV (Saint Venant) model for simulation of large scale tsunami propagation from the source up to coastal scale and the 3D EOLE-NS (Navier-Stokes) model dedicated to tsunami coastal impact modelling. This paper presents a large range of test cases carried out into the frame of the project and dedicated to the validation of numerical codes in various tsunami wave conditions. The main aspects of phenomena such as wave generation, propagation and coastal impact are investigated on academic situations. A real case simulation is concerned as well, the devastating 2011 Tohoku event which is compared with in-situ data.

INTERDIFFUSION, SEGREGATION, AND DISSOLUTION IN InAs/GaAs QUANTUM DOT SUPERLATTICES

2000 ◽  
Vol 07 (05n06) ◽  
pp. 539-545 ◽  
Author(s):  
B. LITA ◽  
R. S. GOLDMAN ◽  
J. D. PHILLIPS ◽  
P. K. BHATTACHARYA
Keyword(s):  
Quantum Dot ◽  
Large Scale ◽  
Ex Situ ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Cross Sectional ◽  
Gaas Quantum Dot ◽  
Novel Devices ◽  
Regular Arrays

We have investigated the effects of in situ and ex situ post-growth thermal annealing on the organization of InAs/GaAs quantum dot superlattices, which consist of regular arrays of InAs islands embedded in GaAs. Using large-scale and high resolution cross-sectional scanning tunneling microscopy, we have mapped out the spatial distributions of the island arrays and the positions of indium atoms located both vertically and laterally between the island arrays. Both in situ and ex situ annealing induce vertical and lateral dissolution of the islands, which in turn significantly affects the organization of the island arrays. Annealing-induced variations in the positions of the indium atoms between the island arrays have enabled us to directly measure indium–gallium interdiffusion and indium segregation lengths. We discuss the effects of residual strain on these processes, which are critical for the design of novel devices based upon semiconductor nanostructures.

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