Abstract: In contrast to the primarily β-sheet structuring of spider and silkworm silks, fibers drawn from honeybee silk glands adopt a distinctive and predominantly coiled coil structure. A recombinant version of the honeybee silk protein Apis mellifera Fibrion 3 (AmelF3) can be fabricated into a variety of material forms making it of interest for the design of functionally active protein-based materials.

Previous experimental studies have shown that the central domain of AmelF3 supports a tetrameric coiled coil structure while recently published computational work revealed that central domain peptide fragments align in an anti-parallel orientation. However, the AmelF3 terminal domains, responsible for the formation and stabilization of larger silk aggregates, have yet to be studied in detail. Atomic level insight about the folding and alignment of these domains is crucial to understanding why honeybee silk protein structuring is so unique and the strengths it offers.

To this end molecular dynamic simulations and bioinformatic protein structure prediction tools were utilized to study folding in C- and N- terminal domain peptides of AmelF3. The predictions of the bioinformatic tools were found to agree well with MD simulations, together providing new insight into the secondary structure distribution and tertiary structure of the 3D folded states of the terminal domains. Differences between solution and solid-state results highlight that significant secondary structural changes in these domains may take place during the silk aggregation process.

Abstract: Oxidative surface treatments of carbon fibre play an important role in the properties of carbon fibre composites. A more thorough understanding and characterisation of the carbon fibre surface heterogeneity is anticipated to assist in understanding the complex issue of failure at the interface between carbon fibre and matrix resin.

In this presentation, using samples obtained from a single tow version of a commercial production line, we investigate the effects of electrolytic bath conductivity on carbon fibre surface oxidation using a range of characterisation techniques, including X-ray photoelectron spectroscopy (XPS) and Raman and Infrared spectroscopy. These characterisation techniques analyse different sample areas and to different depths below the carbon fibre surface. The use of infrared spectroscopy to analyse carbon based materials is inherently challenging due to the strong absorption of the radiation by the carbon, however spectra obtained using a 2000 μm analysis spot (a bundle of fibres) confirmed the presence of surface oxidation species such as carboxyl groups at a depth of approximately 0.44 μm. XPS provides detailed information about the surface chemistry within the outer 10 nm of the sample, from a spot size of 300 μm x 700 μm (representing 10s to 100s of fibres). Both oxygen and nitrogen functionality were detected. In contrast to the large analysis areas covered by these two techniques, Raman spectroscopic mapping enabled the investigation of the surface of individual carbon fibres at a spatial resolution unachievable through many other surface characterisation techniques. The analysis depth of conventional Raman spectroscopy for carbon fibres is estimated at 50 nm, but coating the carbon fibre with nanometer scale noble metal particles it is estimated that the outer 2 to 30 nm of the fibre can be analysed. The analysis of the carbon fibre surface using both approaches suggests clear differences in graphitic structure as a function of sampling depth. The outcome of this study demonstrates the differences in the information provided both spatially and chemically using three spectroscopic based techniques to assess the surface of electrochemically oxidised carbon fibre. This approach has the potential to provide new knowledge relevant to the fibre-matrix interface and thus enable the production of higher performing composites that would greatly benefit the carbon fibre industry.

Abstract: Nanoinformatics is a critical enabling area of nanotechnology that has important implications for both research and commercial developments of engineered nanomaterials (ENMs). The diverse and sustainable development of nanotechnology requires data acquisition, processing, management (collection, validation, storage and sharing), regarding the physicochemical properties of ENMs, their environmental fate and transport, bioactivity, and performance in various applications. Datasets from studies on ENMs are typically unstructured, heterogeneous and often lacking in metadata. Therefore, there is a need for data management that is flexible while providing seamless integration across platforms and modeling tools. Accordingly, in the present work a centralized and integrated database management system, NanoDatabank, was developed with a framework that provides for classification and storage of various ENMs relevant data types. NanoDatabank currently contains data sets on more than about 400 ENM types, 300 investigations regarding ENM toxicity (including metal oxides, quantum dots, CNTs and more) and 150 investigation regarding F&T and ENM characterization. NanoDatabank supports nanoinformatics tools/simulators by providing (a) accessibility to data sets by various simulators and data processing tools, (b) ability to upload raw data and perform various data processing functions, and (c) an intelligent datasets query system. NanoDatabank will be illustrated via recent examples demonstrating the benefit of direct dataset integration with nanoinformatics modeling and data processing tools. A unique feature of the NanoDatabank is a dynamically built taxonomy/ontology and storage ENM information/data with various data access/security levels to allow and promote safe data sharing and storage. In addition, reliability (i.e. clarity regarding exactly what is being reported and trustworthiness/reproducibility) and relevance (i.e. usefulness for a particular purpose) of information is stored in NanoDatabank as metadata along with compressed associated information. To address the issues of data sharing and integration, NanoDatabank uses a range of data converters/utilities to integrate the information among computational tools as part of nanoinformatics platform (nanoinfo.org) for various scenarios such as life cycle assessment of the release of nanomaterials, multimedia exposure analysis of ENMs, QSARs and data driven models for the evaluation of toxicity of ENMs.