New Agilent ion pump controller
accommodates four pumps independently

Agilent Technologies, Inc., (NYSE: A) today introduced the 4UHV Ion Pump Controller, a flexible design able to power, control and monitor independently up to four ion pumps, with capacities ranging from 20 to 500 liters per second each

Image: The 4UHV is the new member of the Agilent VacIon Plus family.

"Due to the controller's low-electrical-noise design, original equipment manufacturers will enjoy the freedom to eliminate or shrink electrical noise filters in critical applications," said Giampaolo Levi, vice president and general manager, Agilent Vacuum Products Division. "Because this new controller shares its communication protocol with our other controllers for turbomolecular and pre-vacuum pumps, less engineering work is required as well."

Agilent offers a portfolio of pumps and systems to create vacuum from atmosphere down to 10^-12 mbar, for a range of industrial and scientific applications, including rotary vane, dry scroll, diffusion, turbomolecular, ion pumps and turbo pumping systems.

The 4UHV is the new member of the Agilent VacIon Plus family, a complete line of ion pumps, controllers, options and accessories dedicated to ultra high vacuum (UHV). Applications include high-energy physics, research and development, nanotechnologies (typically scanning electron microscopes).

For further information, view website: www.chem.agilent.com/en-US/Products/Instruments/vacuum/pumps

Agilent Technologies in profile
Agilent Technologies Inc. (NYSE: A) is the world's premier measurement company and a technology leader in chemical analysis, life sciences, electronics and communications. The company's 18,500 employees serve customers in more than 100 countries. Agilent had net revenues of $5.4 billion in fiscal 2010.

For further information about Agilent , view website: www.agilent.com  Refer to next page

JPK reports on how graphenes are being studied using AFM to
better characterize their properties at the Humboldt University in Berlin

JPK Instruments, a world-leading manufacturer of nanoanalytic instrumentation for research in life sciences and soft matter, reports on a keynote paper in Nano Letters where Dr Nikolai Severin and his co-workers from the group of Professor Jürgen P. Rabe have applied JPK's NanoWizard®II Ultra system to improve their understanding of the properties of graphene.

The Physics of Macromolecules group of Professor Jürgen P. Rabe has a central research goal to correlate structure and dynamics of molecular systems at interfaces with mechanical, electronic, optical and (bio-)chemical properties from molecular to macroscopic length and time scales. Manipulation and imaging of single molecules and supramolecular systems with a scanning force microscope (SFM) is of paramount importance to the understanding of structure formation and the measurement of mechanical properties. The group is also involved in understanding and developing molecular electronics and organic electronic properties.

Within this group is Dr Nikolai Severin, recently the lead author of a paper in Nano Letters* which shows the use of AFM in the study of graphenes. The electronic properties of graphenes depend sensitively on their deformation, and therefore strain-engineered graphene electronics is envisioned. In order to deform graphenes locally, the group has mechanically exfoliated single and few layer graphenes onto atomically flat mica surfaces covered with isolated double stranded plasmid DNA rings. Using scanning force microscopy in both contact and intermittent contact modes, they have found that the graphenes replicate the topography of the underlying DNA with high precision. The availability of macromolecules of different topologies, e.g., programmable DNA patterns render this approach promising for new graphene based device designs. Furthermore, the encapsulation of single macromolecules offers new prospects for analytical scanning probe microscopy techniques.

Dr Severin has seen that graphene provides enhanced protection of DNA molecules to shear forces exerted during scanning force microscopy in contact mode. In addition, graphene will act as a surface protective layer against the ambient, e.g., against oxidation, since it is impermeable to gases. Taking into account both the high electric conductivity of graphene and its extremely small thickness, this offers new opportunities for scanning probe microscopies and spectroscopies, such as scanning tunneling or tip enhanced Raman spectroscopy for analyses of both locally deformed graphene and confined molecules. Summarising, Dr Severin said, "We have successfully demonstrated that topography of graphenes can be controlled with the precision down to single molecules, i.e. graphenes are so flexible that they can replicate the topography of single molecules, when deposited on these molecules."

He also commented on some of the reasons for choosing to work with JPK NanoWizard® II for this work: "We are able to use a relatively large size of samples and scan areas of up to 30 microns. The linearized scanner is most important for us to precisely measure the height of DNA and their cross sections. The system shows little thermal drift which is important when making measurements on such small length scales. I also found the software was quite easy to use."

For further information, view website: www.jpk.com or Facebook: www.jpk.com/facebook  Refer to page 267

CPS nanoparticle size characterisation system

A CPS DC characterisation system from Analytik, a leading supplier of innovative analytical instrumentation, is being used by the Chemical Engineering Department at Loughborough University to study particles in relation to filter and separations technology.

Richard Holdich is a Professor in the Department of Chemical Engineering at Loughborough University. His research interests include a range of particle applications involving various filtration techniques and materials. Applying the CPS disc centrifugation technology, filter efficiency is studied by using particles of less than 2 microns and down to a few 10's of nanometres. Comparison is made between the filtrate/permeate and the material in the feed. The system will also be used to characterise latex and (separately) titania particles that are used in the group's 'cluster size' research where they will mathematically model the size of clusters formed as aggregates. Given the aggregate size, the model then predicts the performance of the aggregates in processing such as their rheological properties, sedimentation behaviour and cake filtration performance. Another project is looking at the success, or otherwise, of different equipment methods used to disperse nanoparticles. Samples will be assessed using the CPS to generate comparative data understanding that the change of aqueous ionic conditions may influence the results.

Professor Richard Holdich from Loughborough University with his CPS DC system.

Prior to using the CPS DC system, the group used a number of techniques. Now, the CPS is run alongside established methods such as PCS, laser diffraction, SEM, TEM, surface area measurement techniques and an acoustic sizer. It has proved particularly useful in the research program. As Professor Holdich says, "We were looking for a device to provide very high resolution providing the ability to determine individual peaks and one that we could use a self-calibration on: i.e. known mass of material used, known volume of liquid, hence from the size distribution we can work out the original mass used and compare with the known mass. This assumes a volume shape factor and density that is constant across the different size ranges. We use this technique a lot for the Coulter Multisizer and have recoveries of above 90% (i.e. match between the known mass used and the calculated mass from the device). Of course, there is a complication with needing Q(net) so this mass balance can only be performed with materials of a known, and reliable, RI and absorption."

While primarily being used to generate data to support on-going research projects, it is envisaged to perform a significant role in future work such as Professor Holdich's mass balance project. This is probably the most academically interesting project. Other projects involving nanoparticles and the methods to make them into engineered systems where they can be readily applied include attachment to surfaces such as polymer membranes (for gas separation), beads (for adsorption and ion exchange) and floating drops (for photocatalytic applications). All these require characterisation of size at high resolution.

The CPS performs nanoparticle size analysis utilising Differential Centrifugal Sedimentation (DCS). This offers the unique ability to resolve very close multimodal particle distributions and to distinguish extremely small shifts in particle size. Rather than using a predictive algorithm, the instrument physically separates the nanoparticles and then measures them as they pass a light source detector and thus provides full characterisation in real time.

To find out more about CPS nanoparticle size characterisation solutions, view website: http://www.analytik.co.uk  Refer to page 287

Linkam temperature controlled stage used to crystallisation
processes in opto-electronic thin films at the Université Libre de Bruxelles

Market leaders in temperature controlled microscopy, Linkam Scientific Instruments, report on the work of Professor Yves Henri Geerts from the Université Libre de Bruxelles where he uses a specially designed temperature stage to study crystallisation processes in opto-electronic thin films.

The Laboratory of Polymer Chemistry at the Université Libre de Bruxelles, unlike the name of the laboratory might suggest, is focused on research into "small molecules", namely, liquid crystalline semiconductors for organic electronics application. Various organic semiconductors have been receiving a great deal of attention in "plastic" electronic devices such as organic photovoltaic cells, light-emitting diodes (OLED) and field effect transistors (OFET). The important physical parameters of microcrystalline films are strongly affected by dimensions of domains and domain boundaries, while large defect-free single crystals are difficult to fabricate and inappropriate for practical applications. At the same time, liquid crystals have been recognized as a new type of organic semiconductors, as they are capable to self-healing of structural defects and to self-organization in large structurally homogeneous domains. Influence of domain boundaries, if any, on carrier transport in liquid crystalline phases is very small.

Professor Yves Henri Geerts and his colleagues in Bruxelles have undertaken a study of single crystal thin films of terthiophene, the building block for the organic semi-conductor polythiophene, by directional crystallization by means of a thermal gradient using the Linkam GS350 stage. The background to this work is to better understand how molecular structure and supramolecular organization affects optoelectronic properties. These can also be affected by the method of fabrication, therefore determining a method to control deposition and crystallisation is important. As part of his research, Professor Geerts used polarized optical microscopy (POM) and X-ray diffraction to characterise the shape, size, and orientation (in and out of the plane of the substrate) of the crystals produced by the thermal gradient technique. He found temperature gradients could potentially be used to control crystal growth and these conditions induce a preferential fast growth direction perpendicular to the gradient direction. In addition it is found that nucleation and growth can be decoupled for OSC crystallizing from the melt in a temperature gradient and that these conditions lead to the generation of highly textured thin films with uniaxial in-plane orientation of crystallites.

The Linkam GS350 was chosen for this work for its ability to accurately programme temperature gradients across the sample. It has two heating elements which are perfectly aligned to ensure uniform thermal contact between the temperature-controlled surface and the sample media. The heating elements are separated by a 2.5mm gap and can be controlled to 0.1°C from -196 to 350°C allowing large, precise temperature gradients to be set up.

The accompanying T95-Linksys controller and Linksys 32 software enables the precision stepper motor to control the position and the speed of sample movement between the two elements and can be used to determine speed of crystal growth and allow the crystallisation front to remain in the field of view. The stepper motor control also enables extremely fast heating or cooling by quickly transferring the sample from one element to the other.

For further information, view website: www.linkam.co.uk  Refer to page 313.