Kuliah Umum Dr Francis Clegg – Sheffield Hallam University, UK

Program Studi Fisika FMIPA mengundang Mahasiswa dan Akademisi untuk mengikuti Kuliah Umum yang akan di sampaikan oleh Dr Francis Clegg dari Materials and Engineering Research Institute – Sheffield Hallam University, UK dengan Tema ” Improving the Water Vapour Barrier Properties of Biopolymers for Packaging Applications ”
yang akan diselenggarakan pada :

Hari / tanggal : Senin, 28 September 2015
Waktu : Jam 09.00 – 10.30
Tempat : Ruang Sidang Lantai 3 Gedung C
Karena terbatasnya tempat mohon untuk datang sebelum acara dimulai.
Berikut Short CV dari Dr Francis Clegg :

Clay-based polymeric nanocomposites, which offer enhanced mechanical, barrier and fire retardant properties to systems used in structural, packaging and coating applications. Particular research themes include:

• Sustainable and flexible high barrier packaging based on clay-polymer composites
• Competitive sorption processes in nanocomposite formulations
• Clay-based shape memory polymers
• Controlled release open wound dressings
• Fire-resistant nano-filled thermosetting polyester resins

Bibliography

Dr Francis Clegg graduated from Sheffield Hallam University in 1994, with a BSc Hons Degree in Applied Chemistry and continued at the same establishment within the Materials and Engineering Research Institute (MERI) to complete a PhD under the tutelage of Prof Chris Breen in 1997. Thisinvolvedinvestigation into the physicochemical properties of organo-mineral interactions and was entitled ‘Thermo-analytical and Spectroscopic Characterisation of Pore Lining Minerals in Reservoir Rocks’.

After a brief one year spell at the University of Newcastle studying the adsorption of organic vapours onto carbon-based materials used in fuel cell technology, Francis returned to MERI to further his research in organo-mineral interactions with particular emphasis on clay-polymer nanocomposites.

As an integral member of the Polymers, Composites and Spectroscopy (PCAS) group for over 15 years, Francis’s research interests arestimulatedby investigationsinto several innovative materials under exploration and development.

The topics of research highlighted above are interconnected andheightenedthrough a healthy interest in clays and their ever-increasing applicationsinboth thermoplastic and thermoset polymer systems as composites. Characterisation of the systems and knowledge of the underlying mechanisms involved are gained by using an extensive range of analytical equipmentavailable at Sheffield Hallam University,with particular emphasis on thermo-analytical techniques (TG, DSC and evolved gas analysis using mass spectrometry) and vibrational spectroscopy.

Other group activities within PCAS include the application of vibrational spectroscopy to the study of controlled release from polymer matrices, polymer formation, gelation and degradation, mapping and imaging of polymer formulations, chemometric data analysis of spectra.

Francis’s time at Sheffield Hallam University is predominantly research based, but he also enjoys a small portion of lecturing to undergraduate chemistry students enlignepharmacie.com.

Recent Publications

FClegg, C Breen, Khairuddin, Synergistic and competitive aspects of the adsorption of poly(ethylene glycol) and poly(vinyl alcohol) onto Na-bentonite. The Journal of Physical Chemistry B, 2014, 118, 13268-13278.

F Clegg, C Breen,Mixed modifier clays and their dispersion in solvent cast polycaprolactone nanocomposites. Applied Clay Science, 85 (2013) 80-87.

MJBarwood, C Breen, F Clegg, CL Hammond, The effect of organoclay addition on the properties of an acrylate based, thermally activated shape memory polymer. Applied Clay Science 102 (2014), 41-50.

C Johansson, F Clegg, Effect of clay type on dispersion and barrier properties of hydrophobically modified poly(vinyl alcohol)–bentonite nanocomposites. Journal of Applied Polymer Science, Volume 132, Issue 28, July 20, 2015, 42229

Berikut Sinopsis dari yang akan disampaikan :

Improving the Water Vapour Barrier Properties of Biopolymers for Packaging Applications

Synopsis:

Food wastage across the world is a hugeproblem economically, socially and politicallybecause the enormous amount of energy that is consumed during its productionis lost. A reduction in food wastage can be overcome by using suitable engineered packaging in order to prolong the shelf-life of food, limit food from perishing and thus allow more to be consumed. If the packaging can be manufactured using bio-based, recyclable, renewable and sustainable materials then a greener and more environmentally friendly alternative to the vastly used petroleum-based products can be offered.

Amongst the many reasons for using packaging, their primary role is to reduce the passage of oxygen and water to the product since they can damage flavours, colours and promote bacterial growth. Biopolymers used as packaging are generally excellent barrier materials against oxygen, but act as poor barriers against water vapour- it is therefore imperative to overcome this if these materials are to be used effectively and commercially.

This presentation will show how clay minerals have been investigated to improve the water vapour barrier properties of starch and plasticiser based coatings, which are applied onto paper or paperboard to achieve flexible packaging. Achieving the low water vapour transmission rate (WVTR) valuesrequired, strongly depends on the type of clay (bentonite) and plasticiser used in the formulation and thus the need to understand their interactions. The plasticiser is a critical ingredient needed to overcome the inherent brittleness of the starch which becomes a major factor when the coated paper is bent or creased. Coatings applied in the laboratory or using pilot scale coating typically and routinely provide robust WVTR values of 10 g (m² day)^-1 when exposed to 50% relative humidity at 23°C.

In additional to a vast amount of analytical, experimental characterisation of the coatings, molecular dynamics modelling has also been investigated in order to provide further insight into how the WVTR is reduced so effectively.

The preparation and antimicrobial activity of silver-bentonite complexes has also been assessed by their incorporation into the starch and plasticiser coating. They have been shown to demonstrate very strong activity towards Escherichia coli, Kocuriarhizophila and Aspergillusniger. Incorporating just 0.03 weight percent of a silver-bentonite complex produced a >4.4 log reduction against an initial loading of 2.1 x 10⁵ CFU/object for Escherichia coli.

The improvement of water vapour barrier properties by thermal and cross-linking processes of the biodegradable polymer poly(vinyl alcohol) will also be discussed.