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Steve Carrington

Kinexus, Taylor Dispersion Analysis, Viscosizer TD »

[19 Nov 2015 | ]

Polymer solution rheology to protein aggregation – Following Sir G.I. Taylor
In a very fortuitous way indeed, from my academic research at Bristol University through to my work here at Malvern, I have managed to maintain a connection with the brilliant work of Sir Geoffrey Ingram Taylor (1886-1975) – who has quite rightly been described as ‘one of the most notable scientists of the 20th century’ [1]. It’s quite probable that many workers will have come across some important contribution from Taylor in their line of research, but may not realize that …

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Rheology, Tech Talk »

[4 Jun 2013 | ]

Suspension Rheology
Understanding rheological properties of suspensions and how particle characteristics are controlling factors
Given the complementary range of materials characterization techniques we have here at Malvern, the measurement of dispersed systems – from suspensions, emulsions and foams, to pastes and gels – is something that we are very familiar with. Our technologies are widely applied at at all stages of the product lifecycle – from particle and molecular characterization of constituent components, to formulation development and stability, to assessment of processing, application and end-use product performance with rheology.
Suspensions or dispersions of particles …

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Corporate, Customer experience, Kinexus »

[7 Feb 2013 | ]
Kinexus rheometer capabilities are really something to chew on

Thinking back to those early design meetings that the development team here at Malvern undertook at the inception of the Kinexus rheometer project, one of our key aims was to deliver a new rheometer platform that enabled total flexibility of control – to provide unique test capabilities that went beyond those previously available on rotational rheometer systems.
Market feedback was telling us that Industrial users would like the option to run under Standard Operating Procedure (SOP)-driven protocols, with ‘locked down’ tests that included specific user instructions and inputs to meet their …

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Corporate, »

[30 Oct 2012 | ]
Is ‘The Blob’ a rheology fright night movie?

If you take a listen to the theme tune for the 1958 B-movie classic ‘The Blob’, you’ll hear a song that sounds bizarrely cheerful and frivolously upbeat, for a film that has probably been the cause of recurring night terrors for many!
Consider some of the words of that song – ‘Beware of the Blob, it creeps, and leaps, and slides and glides…..’ – against a plot of a meteorite that comes to Earth and disgorges a thick viscous mass that oozes from the broken shell, which shows self-locomotion and can …

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Corporate, »

[20 Sep 2012 | ]
Understanding rheological properties – did they do it better in the Sixties??

Prior to coming to Malvern, I spent my time at Bristol University as a researcher looking at rheological properties of non-Newtonian fluids in microfluidic channels. Part of my role was also to give an introductory lecture course on Rheology to undergraduate students, and I clearly recall every year making up polymer solutions and getting together a series of props to try and illustrate some rheological phenomena shown by complex fluids. Rod climbing up a Black and Decker drill was always messier in practice than it looked when illustrated in rheology …

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Corporate, »

[10 Jul 2012 | ]
Rheology and Theology make a biblical connection

If you’ve ever used a spell checker to review an article which includes the word ‘rheology’, then you might have come across a ‘theology’ connection, as that’s what you’re usually prompted to change the word to! But rheology really does have some theological connections, aside from being considered a misprint, and one in particular highlights the importance of understanding the timescale of deformation and the effect that has on a material’s rheological properties.
One of the founding fathers* of rheology, Markus Reiner proposed the Deborah Number – named after the prophetess …

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Tech Talk »

[19 Jun 2012 | ]
Hydrogels – a focus for visionary new biomaterials

Characterizing hydrogels is an area that we are seeing a rapid increase of interest, primarily due to their use in the development of novel biomaterials and in various biomedical applications. Hydrogels are a class of gels – materials with a three dimensional network that spans the volume of a liquid medium – in which water is the dispersion medium.
These soft, pliable materials have the ability to absorb significant quantities of water – as with naturally-occurring materials that play a vital part in all forms of life – making them compatible …

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Tech Talk, Zeta potential »

[29 May 2012 | ]
Dispersion rheology helps keep Euro 2012 in play!

In anticipation of the start of Euro 2012, thoughts probably turn more to the upcoming festival of football (or soccer depending on your whereabouts) – and maybe the odd beer to celebrate or commiserate match results – as opposed to materials characterization that we here at Malvern are involved in daily.
But the two are inextricably linked, as revealed by developments that have led to the new tournament football in use at Euro 2012, where advances in polyurethane dispersion and resin technology are at the forefront.
Such materials are familiar to us …

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[25 Apr 2012 | ]
Unravelling the secrets of the web with rheology

Customer contact is always something that is maintained here at Malvern – with our Customer Support and Technical and Application teams available to ensure our users are able to get the most out of their instruments. Since many of our users are in universities, one particularly interesting aspect for me is being able to keep up to date with the latest research developments that Malvern systems are being used for.
It was a pleasure to be able to catch up again recently with members of the Oxford Silk Group, to hear about …

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[6 Mar 2012 | ]
Is automated DSV set to halt the U-tube trend?

That’s U-tube (Ubbelohde Tube) – not YouTube!
Automated Dilute Solution Viscometry (DSV) systems directly measure the relative viscosity of dilute polymer solutions, allowing the determination of intrinsic viscosity, a parameter that correlates with molecular weight, itself a defining polymer characteristic. Safer, and more accurate than  traditional glassware methods it is easy to find yourself wondering why anyone wouldn’t want to switch to an automated system.
Safer….
The Viscotek DSV solution uses advanced pressure sensing technology and ASTM-approved methodology in a closed loop system. It combines automated sample preparation and low solvent consumption with …

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[26 Jan 2012 | ]
Stretched to breaking point

Yield stress is a commercially useful rheological phenomenon evident in many every day products. Toothpaste and tomato ketchup are excellent examples of materials that exhibit a yield stress and good demonstrators of what it means in practical terms. Both these substances are stationary and solid-like at rest. However, apply a stress that exceeds a critical value – typically by giving the packaging a squeeze or the bottle a sound tap – and out they flow. There’s a lovely rhyme from the American humourist Ogden Nash (1902-1971) that alludes to the …

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Particle size, Zeta potential »

[17 Jan 2012 | ]
Dispersion stability…..what is important?

Suspensions and dispersions are encountered in a wide range of applications, from liquid abrasive cleaners, personal care products, ceramic slurries and medicines to paints and inks. In most cases it is necessary to keep the suspension stable for the product lifetime although, in others, destabilizing the suspension may be a requirement. An example of the latter would be for water treatment or de-aeration.
With this widespread, and ever broadening use of dispersions, the options for ‘product engineering’ to optimize stability is a question that Malvern is often asked due to the …

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Corporate, »

[10 Jan 2012 | ]
Giving rheology a voice

Choirs and glee clubs seem to be the in thing these days. I think its great people can get together socialize and express themselves through their music and there is room for everyone regardless of talent. Do you like to sing? Well maybe it’s not for everyone. But just consider for a moment where you would be without your voice…
Some people rely on their voice for their livelihood. And not only singers, this includes school teachers, ministers, preachers, lawyers and a whole raft of other professionals.
The Department of Communication Sciences …

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Kinexus, Particle size »

[27 Dec 2011 | ]
Easing indigestion through rheological characterization

At some point in our lives, many of us will have experienced indigestion, acid reflux or heartburn – often after a period of over-indulgence – the symptoms of which are not pleasant!
Recent research suggests that in some people acid reflux disease can be caused by abnormal movements of the muscles in the esophagus.
Formulating the perfect remedy
When faced with this situation, many turn to over-the-counter liquid indigestion remedies for relief. These formulations typically contain antacids that neutralize stomach acid and alginates that sooth the pain by coating the walls of the …

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[10 Nov 2011 | ]
Could we soon be waving goodbye to annual flu shots?

With the flu season well underway, many of us will be contemplating a trip to the doctor’s surgery for our annual flu shot. However, recent research suggests that by targeting a preserved region of a protein found in many influenza strains, it might be possible to create a broader flu vaccine that would effectively end the need for these yearly vaccinations.
Ironically, patients who survived infection with the 2009 H1N1 pandemic flu strain developed antibodies capable of protecting the host from a variety of flu strains, which scientists suggest might aid …

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Kinexus, Particle size, Rheology »

[22 Aug 2011 | ]
Rheology – the master chocolatier!

I have always found it fascinating that in the US dark chocolate is often referred to as hard chocolate, because milk chocolate is actually much harder than hard chocolate. It seems softer because it has a lower melting point, just below body temperature, which gives it a softer mouthfeel.
Using rheology to characterize chocolate
The tools of rheology  provide an excellent way of analyzing and characterizing the fundamental material properties of chocolate relating to its manufacture, storage and (most importantly of all in my opinion) eating experience. Smoothness, viscosity, and cohesiveness are …

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[1 Aug 2011 | ]
What is Rheology ?

Rheology in action
For anyone out there who may think rheology is a stressful topic (pun intended), I’d like to share a few visual treats I came across recently.
A video trail
The first in my recommended online viewings is a set of videos on the website of Xion Protective Gear, a company put together by stuntmen in the Netherlands: http://www.stuntpadding.com/. On the home page you will find several entertaining demos and I defy anyone to sit through them without cringing at least once and laughing twice as much.
Those of you who explore …

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Kinexus, Particle size, Rheology »

[5 Jul 2011 | ]
I scream, you scream, we all scream, for ice cream…

For most people, ice cream is a staple requirement of the summer days now upon us, even better when served in a cone on a sunny beach. Europeans have eaten ice cream out of paper cases, seashells, and the edible cones we are now so familiar with, for at least 150 years. However, in the US, the ice cream cone’s inception can probably be traced back to the 1904 World’s Fair in St Louis, Missouri. Popular belief has it that a stallholder selling waffles stepped in to help an ice …

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[6 Jun 2011 | ]
Good rheology

A quick scan of the modern technology that I use every day – my smart phone being an obvious example – reminds me that actually I use only a few of its dazzling capabilities. I get the impression from customers that some feel the same about their high spec rotational rheometers. How to get relevant rheological data is something we’re often asked, and this blog provides me with an opportunity to explore some of these issues further, starting today and over the coming months.
If there are particular areas you’d like …

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Particle size »

[12 May 2011 | ]
Through thick and thin

As rheologists working in a company that excels in materials characterization technology we are in a strong position to explore the links between particle properties and rheological behaviour. This blog is the first in a series that mines a seam discussed in greater detail in the whitepaper: ’10 ways to control rheology by changing particle properties’ .
The focus for today is how to manipulate particle size to influence viscosity.
First the theory…
For a suspension with a fixed concentration of solids the number of particles present is directly proportional to their size. …

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