Oct 10

Hot off the Press: Hydration in Fucoidan-Based Multilayers

The group has just had published a new scientific paper (click HERE) in Langmuir, the premier interfacial science journal of the American Chemical Society.  Tracey Ho (busy writing up her thesis at the moment) has produced the second manuscript from her studies into polymer multilayer coatings based on fucoidan (a seaweed polysaccharide) and chitosan (a polysaccharide derived from crustacean shells).  Read a little more about these ‘sushi sandwich surface coatings’ HERE.
Her first paper was on the comparison of polymer coatings based on two different variants of fucoidan (extracted from two different seaweed species – in this case, by one of our industry partners, Marinova Pty. Ltd.). She found that the source of the fucoidan can control the properties of the coating, providing materials scientists with a simple way to tailor surface coatings for particular applications.
The follow-up paper focuses on films made from one of the fucoidans (from Undaria pinnatifida), and looks at how the layer grows in more detail (how it grows in thickness/mass with each additional layer of polymer), and how that relates to the hydration of the film (the amount of water entrapped within/associated with the polymer coating).  The fucoidan/chitosan hydration was seen to influence the hydrophobicity of the coating (how much it likes/dislikes water), a key film property that can alter its effectiveness in applications such as non-fouling surfaces, and low adhesion coatings.
A description of the paper can also be found on Kudos: http://goo.gl/lKpDwO 
toc image

Oct 10

Hard Work at the Synchrotron

The group just completed an experimental campaign at the Australian Synchrotron.  David, Marta, Jessie, and Natalie spent 4 days (and nights) studying polymer multilayer coatings using infrared microscopy – probing the chemical composition and associated hydration water – the water that binds to the polymer and influences the coating properties.

The experiment involved confining the coating between two surfaces – using a brand new sampling assembly being developed by the scientists at the synchrotron. The new sampling cell allows us to dehydrate the layer through the application of pressure. Not only does this allow us to study the fundamentals of coating composition, it opens up the possibility of studying their lubrication characteristics at the molecular level.
It was a tough set of experiments – these campaigns always are – but Jessie and Natalie were great. Well done both of you – you got some great data.
IMG_1274team

Jun 08

Spreading the Word

One of our team is out spreading the word about SISM science.  Tracey Ho, who is currently writing up her thesis (and doing some postdoctoral work for an industry project – she likes to multi-task), is in Krakow (Poland) this week attending the 15th European Student Colloid Conference (ESC 2015), which is organised by the European Colloid and Interface Society.

She will be presenting new work on the characterisation of her fucoidan multilayers using FTIR spectroscopy, one of the core techniques that we use in the group to study thin films attaching to and growing on surfaces.  The work she will present also includes FTIR data obtained at the Australian synchrotron, which have allowed us to interrogate the hydration water within the multilayers.  Hydration water in these films is thought to influence the ability of the layers to act as lubricants.

Tracey is pictured below outside the Jerzy Haber Institute of Catalysis and Surface Chemistry (Polish Academy of Sciences), where the conference is being held.  SISM Group co-leader, Marta Krasowska, studied there for her PhD.

Tracey in Krakow resample cut

Jun 06

All the World’s a Stage….

Science communication (scicomm) is an important aspect of the SISM Group activities.  Connecting with society and communicating the importance, relevance, and enjoyment of science should be a central goal of all scientists working in universities (see blog post HERE).

This week, David had the chance to talk at The Laborastory, a monthly scicomm event held in Brunswick in Melbourne.  The goal of the Laborastory is to enlighten and entertain, with a focus on painting a picture of the human side of science by encouraging scientists (and science communicators, and teachers, etc.) to talk about one of their scientific heroes.

David talked about William Ramsay, a Nobel prize-winning chemist, who won his Nobel prize for his discovery of the Noble elements (helium, neon, argon, krypton, xenon, and radon).  As well as highlighting the early influences that led Ramsay to pursue chemistry (a gift of a chemistry set to keep him occupied while recovering from a soccer injury), David also talked about Ramsay’s inherently collaborative nature – a characteristic that is very important for scientific discovery.

The website of The Laborastory will post a video/audio recording of David’s talk, but for now, here is a still picture taken by one of David’s co-performers, Cobi Smith.

David at Laborastory

 

UPDATE 🙂

Here is the link to the audio track:

http://thelaborastory.com/stories/william-ramsay/

And here is the link to the YouTube recording:

Apr 25

Beamtime Bonanza!

The SISM group has been successful in two beamtime applications for the Australian Synchrotron in the second cycle of activity for the facility in 2015.  Scientists have to win beamtime through a competitive merit selection process, which is carried out for the numerous experimental installations in the synchrotron.

Scientists from the SISM group will be traveling to Melbourne to do two types of experiments: infrared spectroscopy/microscopy, and X-ray photoelectron spectroscopy.  The synchrotron produces different wavelengths of light, and these different ranges of wavelengths allow us to probe matter in different ways, and for different purposes.

Both applications involve collaborations.  The experiments to be performed using infrared light are for the study of plant nutrient uptake pathways on leaves, and this work is being led by Dr Ryo Sekine (one of our collaborators in the spectroscopy area). This collaboration also involves other researchers from UniSA (Enzo Lombi, Erica Donner, and Thea Lund) and the University of Queensland (Peter Kopittke). The beamtime will be used to get higher quality data to couple with that obtained on the infrared microscope in the SISM Group labs.

The experiments to be performed using X-rays are for the study of novel ionic liquid lubricants.  This collaborative study involves the SISM Group and our friends from ETH Zurich (Antonella Rossi and Andrea Arcifa).  The beamtime will allow us to submit a follow-up scientific paper to our recent work in PCCP.

The group is now going to store up some sleep in preparation for the demanding experimental campaigns (the synchrotron never sleeps 🙂 ).

March synchrotron

 

(The picture above is of the infrared microscopy experimental installation (called an endstation) at the Australian Synchrotron)

 

Mar 13

Update – Cover Story on Seaweed Science

Tracey’s fucoidan multilayer paper is now fully published (with page numbers 🙂 ) – here is the link to the article, and here is the link to the earlier web-post on the article.  It is also featured on the back cover of the journal issue, with a brand new image representing the formed multilayer, and its potential application as a biolubricant.  This artwork was created by the team at Scientific Illustrations (see examples of their other work here), and can be seen below also.  We’re all looking forward to seeing more seaweed science published from Tracey’s work.

Ho Soft Matter Back Cover Image resample

Jan 12

Hot off the Press: A Sushi Sandwich Surface Coating

Tracey Ho from the SISM Group has just had accepted the first paper from her thesis work.  The manuscript is now online at Soft Matter.  Tracey’s thesis work focuses on soft surface coatings, made using the technique of polyelectrolyte multilayer (PEM) formation. PEM formation relies on the sequential adsorption of oppositely charged polymers, building up layer-by-layer coatings that can be used as lubricants, drug delivery vehicles, and as anti-fouling coatings.  Her main interest is in aqueous lubricants – layers that can be used to reduce friction and wear in applications where the lubrication fluid is water (as opposed to oil).

The polymers she uses to make her films are polysaccharides – natural biopolymers that can be obtained from a range of plant and animal sources.  She uses chitosan, which is a common biopolymer derived from crustacean shells, and fucoidan, which is a less commonly studied biopolymer extracted from seaweed.  She calls her surface coatings “sushi sandwiches” 🙂

The first paper focuses on the formation of PEMs using two different fucoidans (extracted from two different seaweed species), and the effect of altered fucoidan chemistry on the layer formation and characteristics.  Tracey has been lucky enough to have support during her PhD studies from Marinova, a Tasmanian biotech company that harvests and processes seaweed to yield exceptionally pure and well-characterised fucoidans.  Dr Damien Stringer from Marinova is one of the paper co-authors.

Well done Tracey.

sushi sandwich

Jan 08

A Return Visit

It seems that when it comes to studying surfactants, bubbles, and foam properties, Susie Warring from the University of Otago just can’t get enough of all the cool equipment we have in the SISM Group.  Susie is visiting the group this month, to continue the work she started in a previous visit (at the same time last year).  Susie is doing her PhD on the adsorption of surfactants to silica surfaces, and the interaction of those surfactants with the air-water interface, and what that means for foams created using the surfactants.

The picture below is of Susie and Iliana (one of the group PhD students), working hard in our class 1000 clean room (hence the interesting attire), measuring dynamic surface tension for different surfactants at the air-water interface.  Welcome back to the group, Susie :).

Susie is back

Jan 05

Happy New Paper Published

The SISM Group has had an ideal start to the New Year – with a manuscript accepted based on some recent synchrotron studies of ionic liquid adsorption to a metal interface.  The paper is now online at the PCCP website (link here).  Ionic liquids (sometimes referred to as room temperature ionic liquids) are being investigated as novel solvents for the production of new chemicals, as components in energy storage devices, and as lubricants.  It is this latter application area that is of major interest for the group, and we are studying how these liquids interact with and stick to metal interfaces, as this will affect their ability to function as lubricants.

The paper just published has a further focus on ionic liquid components (positive and negative ions) adsorbing from solution.  This scenario is more akin to the ionic liquid being used as a lubricant additive (like the classical fatty acids added to engine oil to aid the action of the lubricating fluid).  We used some lab-based techniques available to us at our institute as well as the soft X-ray endstation (pictured below – with Pasindu and Sarah – two of the co-authors on the paper) at the Australian Synchrotron to interrogate the layer of adsorbed ionic liquid on gold.

The study revealed a detailed picture of the ionic liquid layer, and we are performing follow-up studies with other metals.

crop sync

Dec 18

Grant Success and a New Member for the SISM Group

The SISM Group is ending 2014 on a high.  David and Marta (along with Kristen Bremmell and Louise Smith) have won a student project grant from the Wound Management Innovation CRC.  The project research is concerned with studying polymer surface treatments, with a goal of developing new wound dressing materials that enhance healing.

The student project grant will be used to support the research of our new PhD student, Natalie Benbow (pictured below), who has just secured an Australian Postgraduate Award (APA) to come and join the group.  Natalie comes to us from the University of Tasmania, where she recently graduated with a BSc (Honours: Major in Chemistry; Minor in Microbiology).  She will be joining us in February of next year, and we look forward to welcoming her to the SISM family.

Natalie