of 107

Binder 1 | Polymerization | Polymers

14 views
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Share
Description
General introduction HOIM = Hybrid Organic-Inorganic Materials acronym 1 – The HOIM concept a) HOIM definition Traditional composite materials : multiphase material brought about by combining materials that differ in composition or form in order to obtain specific characteristics and properties. ! retain their identities and properties ! act in concert to achieve improved synergistic properties These traditional composite materials, and in particular materials with I fillers in O matrix, have ma
Tags
Transcript
    Introduction to Hybrid Organic-Inorganic Materials / Etienne Duguet / university Bordeaux-1   1 -   1 General introduction HOIM = Hybrid Organic-Inorganic Materials acronym 1 – The HOIM concepta) HOIM definitionTraditional   composite materials : multiphase materialbrought about by combining materials that differ in compositionor form in order to obtain specific characteristics and properties. !!!!   retain their identities and properties !!!!   act in concert to achieve improved synergistic propertiesThese traditional composite materials, and in particularmaterials with I fillers in O matrix, have macroscale domain sizeof micrometerand even millimeter scale. HOIM or nanocomposites or  molecular composites : anew class of composite materials with the physical constraint offew nanometers as the maximum size of the I and/or Ocomponent. !!!! I/O interface tends towards infinite. !!!!   srcinal properties, such as optical transparency. BUT I and O components can not be prepared separatelybefore assembling !!!!   simultaneous syntheses in the same batch !!!!   successive syntheses AND O components are fragile (< 250°C) SO I component processing and/or modification attemperatures substantially lower than those ofconventional ceramic processing conditions :   !!!!  sol-gel process   !!!!  intercalation chemistry      Introduction to Hybrid Organic-Inorganic Materials / Etienne Duguet / university Bordeaux-1   1 -   2 b) why such materials ? When intimately associated I component acts as network former : chemical resistance,mechanical resistance, optical transparency… O component acts as network former or network modifier :processability, hydrophobic/hydrophilic balance, specificproperty as NLO response, biological activity… ! synthesis and application of HOIM have attracted polymer scientists and physicists solid state chemists biologists ceramists inorganic chemists organ(ometall)ic chemistsToday the cooperation between them is very important tounderstand the basic chemistry in conjunction with structure inorder to speed up the applications ! among present applications of HOIM : abrasion resistant coating on plastics decorative and functional coating on glasses coatings and adhesives for glass fibers NLO devices contact lenses …    Introduction to Hybrid Organic-Inorganic Materials / Etienne Duguet / university Bordeaux-1   1 -   3 2 – Classification attempt HOIM could be classified according to the vol. % of the I (or O) component and the size of thedispersed phase dimensional organization types of one component towardsthe other one ceramics   dopedxerogelsfilledxerogelsentangled3D-networksalternated2D-layerscore-shellparticlesmicrocomposites materialsreinforced and/or crosslinkedO polymersO polymers decreasing dimensional organization of one component towards the other one  i      n    c    r    e    a    s    i      n     g     v    o    l      .  %     o    f       I       c    o    m      p    o    n    e    n    t          i   n   c   r   e  a   s    i   n   g     v   o    l .     %   o    f    O    c   o   m   p   o   n   e   n    t   ! simplifying and non-exhaustive classification ! some of these classes do not fulfil the requirements ofnanoscale component size BUT shared feature : the controlled association of I and Ocomponents through the chemical design of innerinterfaces      Introduction to Hybrid Organic-Inorganic Materials / Etienne Duguet / university Bordeaux-1   1 -   4 3 – Class objectives !  just an introduction to HOIM ! rather from the polymer chemist point of view ! description of the chemical   tools : polymer chemistry sol-gel process intercalation chemistry chemical modification of I surfaces ! HOIM examples with their versatile properties andmain applications 4 – Contents 1   General introduction  2   Macromolecular synthesis background   $ Basic definitions $ Classification of polymerization reactions $ Step polymerization $ Chain polymerization : free-radical polymerization3   Sol-gel chemistry and engineering background   $ General mechanisms in the metal-organic route $ Chemical reactivity of metal alkoxides $ Gelation, aging, drying and firing $ Applications and limitations of sol-gel techniques
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks