The interaction of hydrazine with kaolinite was studied using a combination of infrared (IR) spectroscopy,
inelastic neutron scattering (INS), and X-ray powder diffraction. Under ambient temperature and pressure
conditions, anhydrous hydrazine is readily intercalated into the interlamellar region of kaolinite resulting in
a kaolinite−hydrazine (KH) intercalation complex with a 001 d-spacing of 1.03 nm. Under reduced pressure,
the surface loading of hydrazine is reduced to 0.5 hydrazine molecules/unit cell, and the 001 d-spacing of the
KH complex undergoes a partial collapse to a highly ordered KH complex with a 001 d-spacing of 0.95 nm.
This transition from 1.03 to 0.95 nm is accompanied by strong perturbations in the IR and INS spectra for
vibrational modes of both the kaolinite and the intercalated hydrazine species. The transition from the 1.03
complex to the 0.95-nm KH complex is made possible by the keying of one of the hydrazine amine groups
into the siloxane ditrigonal cavity of the kaolinite surface as evidenced by changes of the IR active stretching
and bending modes of the inner OH group. The IR and INS spectra reveal strong hydrogen bonds between
the intercalated hydrazine molecules and the kaolinite surface itself. The strongest hydrogen bonds are
intermolecular hydrogen bonds formed between intercalated hydrazine molecules for the 1.03-nm KH complex
and are manifested by a strong, broad band at 2975 cm-1 in the IR spectrum. This band is absent in the IR
spectrum of the 0.95-nm KH complex and is replaced by a band at 3270 cm-1, indicating a net increase in
the distance between intercalated hydrazine molecules. Additionally, strong intercalation-induced perturbations
occurred for the twist, scissor, asymmetric and symmetric wag modes, and torsional modes of hydrazine for
both the 1.03- and 0.95-nm KH complexes.
Polyaniline, (PANT) in the form of emeraldine base (figure 1), was synthesized by polymerizing aniline in acid solutions at different sub-zero temperatures to give a range of molecular weights between 100,000 and 300,000 gmor1. Molecular weights were measured using gel permeation chromatography (GPC). The polymers were formed into solvent-cast films using an acid processing technique, involving 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) as the solvating/protonating acid group and dichloroacetic acid (DCA) plus formic acid (FA) as the solvent. The dried, free-standing films were stretched by drawing over a hot pin to align the polymer chains. Fibers were prepared by spinning more concentrated solutions into a butanone coagulation bath. Conductivity measurements were then made on the drawn films and fibers, and tensile test measurements performed to determine the peak stress and modulus of the drawn films and fibers. The reaction conditions under which the different polyanilines were synthesized, and their molecular weight, were found to have a definite effect upon both the electrical and mechanical properties of the drawn films and fibers. The drawn films and fibers can be used as mechanical actuators.
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