The Problem
Rapiscan Systems is a subsidiary of US$500m turnover OSI Systems Inc. OSI specialise in electronic, security and monitoring systems for the healthcare, security and optoelectronics market.
Rapiscan were developing a next generation airport security screening system. They were looking for a key development partner to help project manage and deliver a small number of full size prototypes within demanding timescales.
The Challenge
The initial challenge was delivering very high precision cleaning capability as the security screening equipment requires to be operated at high vacuum pressures.
Beyond this there was a need to put together a multi-disciplinary team of experts to enable the prototypes to be delivered within the tight timescales required by Rapiscan.
The Solution
The high precision cleaning capability exists through the SuperClean facility at Daresbury Laboratory. This is one of the few UK facilities that is legally compliant to use the high performance trichloroethane-based technology.
The Science & Technology Facilities Council that operates the laboratory at Daresbury as well as its sister laboratory at Harwell, was able to bring together the necessary team of experts. This covered the areas of advanced engineering & prototyping, instrumentation, control systems and fabrication which were specifically required to deliver this project.
In addition Rapiscan were able to both recruit skilled engineering graduates and access additional R&D expertise through another Campus stakeholder, the University of Manchester.
Finally some core software and electronics technologies required for the project were sourced through existing companies in the Daresbury Innovation Centre.
The Benefits
- Rapid delivery of project to required timescales
- Assembly of wide variety of R&D and advanced prototyping expertise through a single organisation
- Capability to bring in additional skills & technologies through other Campus stakeholders and partners
Background
The surface and interface regions of organic polymers play a vital role in many aspects of modern everyday life. In areas such as biotechnology, electronic devices, composite materials, corrosion protection, packaging and decorative coatings, the properties of polymer surfaces and interfaces have an important influence on the performance of technology.
Polymers are amenable to controlled surface modification processes such as flame or plasma treatment or the use of a surface segregating chemical component, thus allowing surface properties to be optimised while retaining desirable bulk properties.
The Challenge
| Scientists from the National Centre for Electron Spectroscopy and Surface Analysis (NCESS) at Daresbury Laboratory, set out to characterise the uppermost surface regions (1 - 5 nm) of a wide range of technologically important polymers, using x-ray photoelectron spectroscopy (XPS), specifically using the NCESS ESCA300 XPS spectrometer. |  |
The solution
For poly(ethylene terephthalate) (PET), widely used in bottles, packaging and film, the high energy resolution of the ESCA300 spectrometer was used to discover that the shape of the polymer chains subtly influences the XPS spectrum thus providing a diagnostic for the crystalline/amorphous nature of the polymer surface.
The benefits
The high energy resolution of the ESCA300 was also used to show that thermal treatment of PET causes the surface chains to rearrange more quickly than those in the bulk. For poly(ethylene glycol) (PEG) the high intensity of the spectrometer was used to demonstrate that the chain shape influences the XPS spectrum, again providing a diagnostic for the crystalline/amorphous nature of the surface.
The blending of polymers is an important way of modifying both bulk and surface properties. However polymer blends are complex and require a multi-technique characterisation approach. Polymer blend thin films often behave very differently from the bulk materials. Current work at NCESS uses XPS and AFM (Atomic Force Microscopy) to investigate polymer blends as a function of molecular weight and film thickness. This will ultimately feed into an improved understanding of polymer blend thin film devices such transistors and displays.
Other applications
Polymers are often reinforced with fibres (e.g. carbon fibre, glass fibre) or powders to generate stronger and tougher composite materials and there is currently much interest in using nanoscale reinforcement to produce nanocomposites with improved properties. The surface chemistry of the nanomaterial is crucial as this provides interfacial bonding between the polymer and the nanoparticles. Scientists from NCESS and the Universities of Liverpool and Florida State have characterised the surfaces of carbon nanotubes (CNT), nanodiamonds (ND) and silica nanoparticles for use in polymer composites. It has been found, for example, that CNTs coated with ND considerably improve the ballistic resistance of composites for body armour applications.
The future
The NCESS research programme into polymer surfaces is set to continue into the future and interested parties are encouraged to contact the Unit either directly or via Daresbury SIC.
Click here to view the full case study detailing NCESS' x-ray photoelectron spectroscopy characterization of technological polymer surfaces.