08/12/2021
Marie Skłodowska-Curie Actions

MSCA-COFUND-CLEAR-Doc - PhD Position #CD21-22 "Controlling hygrothermics of biobased construction material"

This job offer has expired


  • ORGANISATION/COMPANY
    Université Gustave Eiffel
  • RESEARCH FIELD
    EngineeringThermal engineering
    PhysicsThermodynamics
  • RESEARCHER PROFILE
    First Stage Researcher (R1)
  • APPLICATION DEADLINE
    21/03/2022 17:00 - Europe/Brussels
  • LOCATION
    France › Marne-La-Vallée
  • TYPE OF CONTRACT
    Temporary
  • JOB STATUS
    Full-time
  • HOURS PER WEEK
    35
  • OFFER STARTING DATE
    01/10/2022
  • EU RESEARCH FRAMEWORK PROGRAMME
    H2020 / Marie Skłodowska-Curie Actions COFUND
  • REFERENCE NUMBER
    101034248
  • MARIE CURIE GRANT AGREEMENT NUMBER
    101034248

OFFER DESCRIPTION

Reducing energy expenses and greenhouse gas emissions associated with heating or cooling down the housing depends largely on the use of good thermal insulator materials in construction. Insulating materials in construction are fibrous porous systems (glass wool, stone wool, sheep’s wool, wood wool, cellulose wadding, etc) or more complex porous structures (terracotta, lime, plaster). On another side, standard walls in wood, mortar, bricks, plaster, which are also porous systems, ensure a significant part of the building insulation. The use of various alternative bio-based materials is currently growing, such as natural fibers derived from wheat, jute, flax, bamboo, straw, coir, etc, for insulation, and the dispersion of vegetal elements (wood, hemp, cellulose wadding, straw, etc) in a cementitious matrix for walls. The value of these materials is that in addition to their finely divided porous structure with a large porosity, they are hygroscopic, i.e. they can absorb a significant fraction of water in the solid structure, which is transported or released (evaporation) depending on external conditions.

Basically these materials are characterized by their thermal conductivity, which is generally determined under given humidity conditions. However, this characteristics can be significantly affected by moisture transfers through the structure, which continuously occur as a result of humidity variations inside and outside housing. The impact of moisture results from its simple presence in contact with the solid structure, and to the thermal exchanges due to vapor transport then condensation or evaporation (which, due to the large latent heat of water, can induce huge amounts of energy transfer). Moreover, with hygroscopic materials such as cellulose-based materials, bound water transfers allow the walls to ensure a further comfort to people, as they now tend to regulate the ambient humidity. Thus it is crucial that the design of new buildings and renovation projects could rely on a proper evaluation of the “hygrothermics” of the used materials.

The moisture transfer process in the building envelopes is generally not taken into account in the current conventional thermal calculation and energy consumption analysis. Sophisticated “hygothermal” models have been developed in literature which take into account at best all the internal processes (vapor transport, sorption, etc), but since they do not distinguish dominant physical processes, they generally involve a lot of a priori unknown parameters. Moreover the predictions of these models can hardly be fully validated due to the absence of appropriate measurements of internal physical quantities.

The major problem hindering progress is the lack of information and proper description of water transport and phase changes inside the porous structure. Measurements remain challenging, in particular considering that the materials are non-transparent and different states of water (free liquid water, bound water, vapor) can coexist.

The Navier Laboratory has a Magnetic Resonance Imager (MRI) and several NMR Spectrometers for applications in civil engineering. We recently achieved a world first by demonstrating the possibility to measure the evolution of the distribution of free and bound water in wood, with the help of appropriate NMR and MRI sequences (T2 distribution in time, multi-echo alternating with Single-Point-Imaging). Here we propose to apply such techniques to model porous fiber packings representing the two main classes of insulating systems, typically a non-hygrophilic glass wool and hygrophilic cellulosic packing, subjected to various boundary conditions (temperature, relative humidity). In addition we will carry out experiments under similar conditions, outside the NMR spectrometers, to get information on the temperature distribution along the sample axis. An experimental set-up to measure the temperature along the sample axis and/or the heat exchanges during the process will be developed in that aim.

Moreover, complementary in-situ X-ray imaging and X-ray wide- and small-angle X-ray scattering (SAXS/WAXS) are planned in a collaboration with P. Huber to correlate the NMR data with spatio-temporally resolved water distributions in pore space. These goals shall particularly profit from a 6 months visit in P.Huber’s lab in Hamburg as well as joined experiments at synchrotron-based X-ray beamlines at PETRA III (Hamburg), or at ESRF (Grenoble) and Soleil (Paris).

We will thus obtain a complete set of data concerning the hygrothermal evolution of a model system under controlled boundary conditions. This will allow us to develop models taking into account the different transport and transfers between phases and fully validate it by comparison with data at a local scale. This is a unique situation in the field of construction materials.

In a final step of the PhD work we will carry out the same approach for model bio-based construction materials made of the dispersion of cellulose packing in a clay or cement paste.

This work should lead to a clarification of the physical processes at work in various insulation and bio-based construction materials, provide some relevant means for their characterization, offer some practical recommendations on the most appropriate characteristics, and open the way to the development of new high performance materials.

This work will be mainly carried out within Laboratoire Navier, Physics and Porous Media Team, with P. Coussot (http://philippecoussot.com) as official supervisor, and in collaboration with R. Sidi-Boulenouar and B. Maillet from the NMR Team, and S. Caré from the team Materials for Advanced Structures. This team has developed, over the last 10 years, original fundamental and applied researches on drying, imbibition, deformation, of construction materials (wood, cellulose, plaster, hemp concrete, soils, concrete, etc), with the help of X-ray and NMR techniques. Some of these works were carried out within the frame of industrial contracts with CSTB (Centre Scientifique et Technique du Bâtiment), Saint-Gobain, CEA, and Lhoist.

The work will also be carried out in collaboration with Patrick Huber group (https://huberlab.wp.tuhh.de) in Hamburg, where the student will spend at 6-9 months. P. Huber develops top-level fundamental research in condensed-matter physics and on novel functional materials. Recently, his research group also joined the Deutsche Elektronen-Synchrotron DESY (https://www.desy.de) in Hamburg and employs there in-situ X-ray imaging and diffraction methods for the exploration of transport in, and interaction of liquids with, porous solids.

More Information

Benefits

  • High-quality doctoral training rewarded by a PhD degree, delivered by Université Gustave Eiffel.
  • Access to cutting-edge infrastructures for research & innovation.
  • Appointment for a period of 36 months based on a salary of 2 700 € (gross salary per month).
  • Job contract under the French labour legislation in force, respecting health and safety, and social security: 35 hours per week contract, 25 days of annual leave per year.
  • International mobility will be mandatory.
  • An international environment supported by the adherence to the European Charter & Code.
  • Access to dedicated CLEAR-Doc trainings with a strong interdisciplinary focus, together with a Career development Plan.

Eligibility criteria

  • At the time of the deadline, applicants must be in possession or finalizing their Master’s degree or equivalent/postgraduate degree. At the time of recruitment, applicants must be in possession of their Master’s degree or equivalent/postgraduate degree which would formally entitle to embark on a doctorate.
  • At the time of the deadline, applicants must be in the first four years (full-time equivalent research experience) of their research career (career breaks excluded) and not yet been awarded a doctoral degree. Career breaks refer to periods of time where the candidate was not active in research, regardless of his/her employment status (sick leave, maternity leave etc). Short stays such as holidays and/or compulsory national service are not taken into account.

  • At the time of the deadline, applicants must not have resided or carried out their main activity (work, studies, etc.) in France for more than 12 months in the 3 years immediately prior to the call deadline.

  • Applicants must be available to start the programme on schedule (around 1st October 2022)

Selection process

Additional comments

  • The First step before applying is contacting the PhD supervisor. You will not be able to apply without an acceptation letter from the PhD supervisor.
  • Please contact the PhD supervisor for any additional detail on job offer.
  • There are no restrictions concerning the age, gender or nationality of the candidates. Applicants with career breaks or variations in the chronological sequence of their career, with mobility experience or with interdisciplinary background or private sector experience are welcome to apply.

Web site for additional job details

Offer Requirements

  • REQUIRED EDUCATION LEVEL
    Physics: Master Degree or equivalent
    Engineering: Master Degree or equivalent
  • REQUIRED LANGUAGES
    ENGLISH: Good

Skills/Qualifications

  • At the time of the deadline, applicants must be in possession or finalizing their Master’s degree or equivalent/postgraduate degree.
  • At the time of recruitment, applicants must be in possession of their Master’s degree or equivalent/postgraduate degree which would formally entitle to embark on a doctorate.

Specific Requirements

A 6 to 9-month secondment at TU Hambourg (Germany).

Work location(s)
1 position(s) available at
Université Gustave Eiffel
France
Marne-La-Vallée
77454
5, Boulevard Descartes

EURAXESS offer ID: 716933

Disclaimer:

The responsibility for the jobs published on this website, including the job description, lies entirely with the publishing institutions. The application is handled uniquely by the employer, who is also fully responsible for the recruitment and selection processes.

 

Please contact support@euraxess.org if you wish to download all jobs in XML.