Tuning selective gas transport in polymers by manipulation of molecular orientation

Polymer films are used extensively for packaging due to their processability, lightweight and transparency. The barrier properties of such films is, as would be expected, also a crucial property, particularly when used for food packaging. In some cases it is crucial to keep gases within the barrier, in other instances keeping gases from penetrating to the contents within.<br /> <br /> Occasionally it is also advantageous to have a specially designed barrier, which would allow selective transport of particular gases in either direction. One key aspect of the polymer film that can potentially be modified during melt processing, or a subsequent solid state processing stage, is the level of preferred molecular orientation within the film. If the rate of deformation used to manufacture the film is faster than the relaxation time of the polymer chain (often controlled by the entanglement time), then the polymer chains can be trapped in a preferred orientation.<br /> <br /> These effects might be used to custom design polymer films for important physical properties such as preferential gas transfer. The aim of this project is to assess whether preferred molecular orientation can be used to affect gas transport, and for what particular single gas (oxygen, nitrogen, water vapour etc) or gas mixtures. Careful annealing of oriented films can produce different levels of molecular orientation at different length scales, and the interest is to see if this can be used to tailor gas transport.<br /> <br /> The project will use small scale, but relevant, processing facilities at Leeds to manufacture films with controlled levels of orientation. The trapped orientation, and its dynamics, will be assessed by a range of experimental techniques all available at Leeds including dielectric spectroscopy, birefringence, differential scanning calorimetry and rheology, as well as the important underpinning gas diffusion measurements.

<p>Formal applications for research degree study should be made online through the&nbsp;<a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University&#39;s website</a>. Please state clearly in the Planned Course of Study that you are applying for <em><strong>PHD Physics &amp; Astronomy FT </strong></em>and&nbsp;in the research information section&nbsp;that the research degree you wish to be considered for is <em><strong>Tuning selective gas transport in polymers by manipulation of molecular orientation</strong></em>&nbsp;as well as&nbsp;<a href="https://physicalsciences.leeds.ac.uk/staff/117/dr-johan-mattsson">Dr Johan Mattsson</a> as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University&#39;s minimum English language requirements (below).</p> <p style="margin-bottom:11px"><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p> <p class="MsoNoSpacing">Applications will be considered on an ongoing basis. &nbsp;Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. &nbsp;We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p>Please note that you must provide the following documents at the point you submit your application:</p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> <li>Funding information including any alternative sources of funding that you are applying for or if you are able to pay your own fees and maintenance</li> </ul>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p style="margin-bottom:12px"><strong>Self-Funded or externally sponsored students are welcome to apply.</strong></p> <p><strong>UK</strong>&nbsp;&ndash;&nbsp;The&nbsp;<a href="https://phd.leeds.ac.uk/funding/209-leeds-doctoral-scholarships-2022">Leeds Doctoral Scholarships</a> and <a href="https://phd.leeds.ac.uk/funding/234-leeds-opportunity-research-scholarship-2022">Leeds Opportunity Research Scholarship</a> are available to UK applicants. The&nbsp;<a href="https://phd.leeds.ac.uk/funding/102-bell-burnell-scholarship-award-awarded-by-the-iop">Bell Burnell Scholarship Award</a>&nbsp;is available to support applicants who are from groups that are currently under-represented in physics (awarded by the IOP).&nbsp; <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds.</p> <p><strong>Non-UK</strong> &ndash; The&nbsp;<a href="https://phd.leeds.ac.uk/funding/102-bell-burnell-scholarship-award-awarded-by-the-iop">Bell Burnell Scholarship Award</a>&nbsp;is available to support applicants who are from groups that are currently under-represented in physics (awarded by the IOP).&nbsp; &nbsp;The&nbsp;<a href="https://phd.leeds.ac.uk/funding/48-china-scholarship-council-university-of-leeds-scholarships-2021">China Scholarship Council - University of Leeds Scholarship</a>&nbsp;is available to nationals of China. The&nbsp;<a href="https://phd.leeds.ac.uk/funding/73-leeds-marshall-scholarship">Leeds Marshall Scholarship</a>&nbsp;is available to support US citizens. <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds.</p> <p><strong>Important:</strong>&nbsp; Any costs associated with your arrival at the University of Leeds to start your PhD including flights, immigration health surcharge/medical insurance and Visa costs are <strong>not</strong> covered under these studentships.</p> <p>Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information about your application, please contact Doctoral College Admissions: e:&nbsp;<a href="mailto:EMAIL@leeds.ac.uk">m</a><a href="mailto:maps.pgr.admissions@leeds.ac.uk">aps.pgr.admissions@leeds.ac.uk</a></p> <p>For further information about this project, please contact Dr Johan Mattson: e:&nbsp;&nbsp;<a href="mailto:K.J.L.Mattsson@leeds.ac.uk">K.J.L.Mattsson@leeds.ac.uk</a></p>