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ROHARCANA

Project title:  "NANOCOMPOZITE PE BAZA DE NANOTUBURI DE CARBON"

Acronym:  ROHARCANA

Field:  theme 4 "Nanosciences, Nanotechnologies, Materials and New Production Technologies"

Romanian team:
      Dr. Cristian Petcu - Project Manager, CS II
      Dr. Dan Donescu - Scientific Manager, CS I
      Dr. Zina Vuluga - Specialist, CS I
      Dr. Cosmin Mihai Corobea - Specialist, CS III
      Dr. Violeta Purcar - Specialist, CS III
      Dr. Raluca Ianchis - Specialist, CS III
      Dr. Raluca Munteanu - Specialist, CS III
      Dr. Cristina Lavinia Nistor - Specialist, CS
      Chem. Michaela Doina Iorga - Specialist, CS III
      Phys. Marius Ghiurea - Specialist, CS

Partners:
      GKSS-Forschungszentrum Geesthacht GmbH, Germany
      Regie Ecole Superieure de Physique et Chimie Industrielles de Paris, France
      Materia Nova, Belgium
      Universite de Liege, Belgium
      National R-D Institute for Chemistry & Petrochemistry, Romania
      GMT Membrantechnik GmbH, Germany
      Borsig Membrane Technology GmbH, Germany
      Universite Catholique de Louvain, Belgium
      Consejo Superior de Investigaciones Cientificas, Spain
      Emerson & Cuming Microwave Products N.V., Belgium
      FutureCarbon GmbH, Germany
      Inergy Automotive Systems Research sa, Belgium

Resources:
      Environmental Scanning Electron Microscope
      Measurement System of Particles Dimensions by DLS
      Fourier Transformate Infrared Spectrometer (FTIR)
      UV-VIS Spectrophotometer
      Centrifuge 9000 rpm
      Lyophilizer
      XRD
      Autoclaves
      Analytical Electronic Balances
      Bath Circulators
      Laboratory Instruments for Syntheses and Characterizations
      Computers and Periferic Equipments with Internet connexion

Partial results:
      •  The selected polymeric systems have a great potential for developing of advanced materials with superior properties;
      •  The CNT's decoration method with polymers is a viable solution from technological point of view and also, from compatibility at phase level (the later dispersion of some CNP masterbatches in a system based on the same polymer used for decoration);
      •  The suspension polymerization of AcN is not viable for the studied systems due to its reaction isotherm;
      •  The suspension polymerization in the presence of CNT induces the formation of heterogeneous blocks formed from used partners;
      •  The polymerization reaction (by suspension polymerization method) didn't prove to take place in the vicinity of CNT;
      •  In the case of PAcN exist a great affinity for CNT comparing with the other used systems;
      •  The aggregated CNT masterbatch in PAcN could be later dispersed from aqueous medium into the PAcN mass, poor in CNT;
      •  The dispersion polymerization of AcN allows a better control of reaction isotherm comparing with suspension polymerization;
      •  The microsolubilization in systems such as emulsion, miniemulsion, microemulsion is future direction to obtain the homogeneity of mass reaction, but also for the control of reaction isotherms. The preliminary results confirm that aspect;
      •  CNT are filamentary systems with advanced form factor that require intensive dispersion treatments in order to compatibilize with either liquid or solid (polymer) systems;
      •  The dispersion procedures that use mechanical mixing systems are insufficient for dispersion in aqueous solutions of unfunctionalized CNT;
      •  The dispersion of CNT can be achieved by selective interaction with surfactants;
      •  The optimum dispersability was achieved through surfactants that can provide (through their structure) interactions of "π-π" (or "π-π stacking effect"). Hydrophobic associations at this level are strong enough to ensure the dispersability. The interaction is almost similar to that of their structures that form the CNT walls;
      •  The use of ultrasonic procedures can improve CNT dispersability both for organic phases (monomer in this case) and for aqueous phases;
      •  There is an optimum energy for ultrasonic processes to obtain dispersability with homogeneous character. Using a too large energy dispersion can result in the supplementary introduction of defects in the CNT surface or even their partial fracture. The appearance of additional superficial defects in the CNT surfaces can be an advantage for radical attack currently in-situ synthesis of polymer;
      •  Obtaining optimal conditions for ultrasound treatment is heavily dependent on volume unit. In terms of working hypotheses must choose a system that, at least theoretically, can allow spatial arrangement at individual level of CNT particles. Systems under theoretical percolation concentration may not present homogeneity;
      •  Using the combined dispersion procedures (ultrasonic in surfactant-mediated systems) presents the best efficiency compared with the rest of the studied procedures;
      •  The use of functional monomers as vinyl carbazole type can average at chemical level (through in situ modification of CNT surface) the dispersabily in ultrasound field;
      •  Chemical modification of CNT surfaces is a viable way to increase dispersability and interaction with polymers;
      •  Chemical modification has the effect of reducing the polarity difference between substrate and less hydrophobic monomers;
      •  The use of reactive functions for the polymerization process has the advantage of interface hardening in CNP-polymer systems. On the other hand the use of molecules serve as the "extender" (maleic anhydride) may create prerequisites for systems with controlled flexibility;
      •  Have been successfully implemented on CNT different functionalization of aniline and maleic anhydride in order to compatibilize with polymers;
      •  The use of functionalized CNT allows in situ synthesis by miniemulsion polymerization of CNT-polymer nanocomposites at high conversions;
      •  In order to determine the formulations of disperse systems for this study have been performed polymerization tests in emulsion, suspension and miniemulsion;
      •  The systems that provided the best dispersion of CNT in the initial dispersions of monomers and final of polymers, have been those for miniemulsion;
      •  The composites were obtained in dynamic conditions in a Brabender plastograph, using two types of concentrates containing 2% CNT:
         -  a concentrate prepared by miniemulsion (in-situ polymerization of PSt/SAN grafted on CNT),
            noted PSt/SAN-C;
         -  a concentrate obtained by physical mixing of PSt/SAN with 2% CNT in the mixing chamber of
            Brabender plastograph, noted PSt-SAN-B;
      •  Dynamic storage modulus (E') of PSt composites decreases with increasing temperature and increases with CNT concentration. The highest value of E' was obtained at 30°C and 1% CNT, using PSt-B concentrate;
      •  In the case of composites obtained with PSt-C concentrate, around Tg value of PSt, E' decreases with the concentration of CNT. This behavior may suggest that PSt-C can act as plasticizer for PSt;
      •  The loss modulus, E''max, increases by about 1% for composites obtained with PSt-B/C concentrate compared with PSt;
      •  E' for SAN-based composites had a similar behavior with PSt-based composites: decreases with increasing temperature and increases with CNT concentration. The highest value for E' was obtained at 30°C and 1% CNT using SAN-B concentrate;
      •  In the case of composites obtained with SAN-C concentrate, at around Tg of SAN's E' decreases with the concentration of CNT. This behavior suggests, that in the case of PSt, that SAN-C can act as a plasticizer for SAN;
      •  The loss modulus E''max, increases by about 1% for the composites obtained with both concentrates SAN-B/C, comparing with SAN.

Project Impact:
      The impact of the project could be quantified on two levels: first for the next time, to obtain valuable scientific results in order to increase the fundamental knowledge in nanosciences fields and second for long term, to develop new applications for nanocomposites. Also, the project impact would be reflected in a social plan in order to organize and coagulate a research team of excellence. The project creates the premises for young researchers to be involved in scientific activities at international level. Based on obtained results it would develop other topics and directions for research. The accumulated experience could be exploited to generate other national and international projects. This has finally impact on increasing the number of research jobs and superior capitalization of workforce presented in local team. The scientific results would be exploited and extended also at the training programs. The long term impact will also materialize in the increasing of training level of Romanian specialists and in superior quality of training programs.

Dissemination:
      The dissemination of results will achieve by communication and publishing in scientific media, which will evaluate their value and contribution. It will follow the visibility increasing of Romanian research in world wide publications, ISI Thomson indexed.

Contact person:
      Project Manager: Dr. Cristian PETCU, CS II, Polymer Department, INCDCP-ICECHIM
      Spl. Independentei nr.202, sect.6, 060021, Bucharest
      tel. 021.316.30.93, fax 021.312.34.93
      e-mail: cpetcu@icf.ro
      Web Page of the FP7 project: www.harcana.eu