BaTiO3/ Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO3 nanocrystal in tetragonal system and polyurethane(PU)/ unsaturated polyester (UP) interpenetrating polymer networks (IPNs). The tetra gonal nanocrystalline BaTiO3 was obtained by hydrothermal process and calcinatio n at 1 200 ℃. The prepared materials were polarized with high voltage a nd small current, and protected by silicon oil. The morphology of BaTiO3/ IPNs and the effect of combination of BaTiO3 on the damping behavior of IPNs were stu died. The relationship between damping performance and dielectric charater was a lso discussed in terms of dielectric constant and dielectric loss measured. The results show that the areas under loss modulus (E″) and the values of loss fact ors (tanBaTiO3 into IPNs system. The m aximum value of E″ increased above 100 MPa compared with pure IPNs and the exte nt increased more remarkably after polarizing process. The main and shoulder pea k of tand the temperatu re ranges of tan℃. Moreover, through polarizing proc ess, the composites exhibited synergistic action caused by elastomeric damping, interfacial abrasive damping and piezoelectric damping mechanisms. The relations hip study of damping property and dielectric characters showed that the temperat ure ranges exhibited excellent consistency of maximum dielectric loss and modulu s with damping loss factor.
In this work, we succeeded in the preparation of LiNb 1- x Ta x O 3 films on Si(111) substrates by means of sol gel process, and the usual sol gel process for the preparation of LiNbO 3 and LiTaO 3 films on Si substrates was improved by adding a 33% aqueous solution of CH 3CH 2OH to the mixed sols of LiNb(OCH 2CH 3) 6 and LiTa(OCH 2CH 3) 6 . The crystallization behavior of LiNb 1- x Ta x O 3 films on Si(111) substrates has been studied. Highly c axis oriented LiNb 1- x Ta x O 3 films have been obtained within the tantalum composition range of \{0< x <0 33\}. Some factors such as the hydrogen termination of the silicon surface, the RTP annealing process that provides the unidirectional heat flow and the preheating temperature are discussed to analyze the crystallization of the c axis oriented films.
A possible isomerization channel from BrONO (bromine nitrite) to BrNO2 (nitryl bromide) is predicted by means of MP2 and QCISD(T) (single-point) methods. The channel is a direct bromine abstraction reaction from BrONO molecule by NO2 in which the forward reaction barrier is 89.30 kJ/mol at final UQCISD(T)/6-311+G(2df)//UMP2/6-311G(d) level of theory with zero-point energies included. The result can explain the available experiments very well.
