Title of article :
The structure of amino-functionalized polyhedral oligomeric silsesquioxanes (POSS) studied by molecular dynamics simulations
Author/Authors :
Neyertz، نويسنده , , S. and Brachet، نويسنده , , P. and Brown، نويسنده , , D. and Mنnnle، نويسنده , , F.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Pages :
8
From page :
258
To page :
265
Abstract :
Molecular models of three amino-functionalized cubic polyhedral oligomeric silsesquioxanes (POSS) have been studied at 293 K using classical molecular dynamics (MD) simulations. These hybrid organic/inorganic systems were all based on the T8R8 form, but they differed by the end-groups of their organic pendant chains, i.e. either R = –(CH2)3–NH–CO–C6H5OH, R = –(CH2)3–NH–CO–C6H6 or R = –(CH2)3–NH–CO–C6H11. Model densities, volumes, cohesive energies, void spaces, X-ray diffractograms and intermolecular as well as intramolecular interactions were analysed. The differences in bulk and structural properties between both aromatic-based organic chains are fairly small, although the added hydroxyl groups bring additional cohesion by modifying the amide⋯amide H-bonding network. On the other hand, replacing an aromatic by a cyclohexyl ring leads to molecular disorder, larger POSS⋯POSS separations and a lower density. The pendant arms of the three POSS under study were found to be intertwined with a preference for intermolecular interactions because of steric considerations. Such an interdigitation also allowed for the parallel stacking of the ring end-groups at short distances, thus bringing extra cohesion to the systems. However, there was no evidence of long-range crystalline order.
Keywords :
Organic chains , Molecular dynamics (MD) , structure , POSS , Amino-functionalized
Journal title :
Computational Materials Science
Serial Year :
2012
Journal title :
Computational Materials Science
Record number :
1689795
Link To Document :
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