A large-scale carbon nanotube∕CoFe2O4 (CNTs∕CoFe2O4) spinel nanocomposite has been fabricated by a chemical vapor deposition method using CoFe2O4 nanoparticles as catalysts. A uniform mixture of CNTs and CoFe2O4 nanoparticles was obtained simultaneously. The structure and chemical composition of the product were investigated using various techniques, such as x-ray diffraction, high-resolution transmission electron microscopy, and electron energy loss spectroscopy. It was found that the particles functionalized on CNTs were cubic phase CoFe2O4. Microwave absorption of the CNT∕CoFe2O4 nanocomposites at 2–18 GHz is evidently enhanced, as compared with that of both pure CNTs and CoFe2O4 nanoparticles. The enhancement mechanism is discussed based on magnetization hysteresis loop measurement and electromagnetic theory.

The infrared spectrum of polyethylene has been obtained between about 3000 cm-1 and 70 em-I, polarization measurements on oriented specimens having been obtained to about 350 em-l. Assignments of the fundamentals are made with the help of a group theory analysis. The assignment of the controversial CH. wagging mode is discussed in detail and especially in terms of new evidence from the spectra of n-paraffins, both as single crystals and as polycrystalline aggregates. It is shown that this mode is to be assigned to a weak band at 1369 cm-l. A satisfactory determination of the bands which arise from CHa groups is also made possible by a study of the paraffin spectra. The splitting of bands in the spectrum is conclusively shown to arise from interactions between molecules in the crystalline phase. The nature of this interaction is discussed in terms of recent theories.

The polarized infrared spectra of crab chitin crystallites, blowfly larval cuticle, lobster tendon, and partially deacetylated lobster chitin have been studied. In addition, the spectra of amorphous deacetylated chitin, deuterated lobster chitin and crystalline N‐acetylated chitohexaose were obtained and analyzed. Band assignments have been made with the aid of previous work on celluloses and other related molecules. The complete intermolecular CO‐‐‐‐HN hydrogen bonding scheme, orginally proposed by Carlstrom from x‐ray studies, is in agreement with the infrared data. With the aid of a scale model of the chitin unit cell, a number of hydrogen‐bonding schemes involving the primary hydroxyl group have been examined and are discussed.

The infrared spectra of oriented films of valonia cellulose and of ramie and bacterial cellulose crystallites have been observed in the 3 μ region. Polarization properties of the bands have also been determined. The differences between the polarized spectra of bacterial and ramie crystallites in this region are attributed to per cent crystallinity and orientation effects. Two new bands in the CH stretching region have been observed. With this new information the CH2 symmetric and antlisymmetric stretching modes are assigned to parallel and perpendicular bands, respectively, requiring a specific orientation of the CH2OH group. From the observed polarization of the bands in the OH stretching region, a system of hydrogen bonding in the crystal structure of cellulose I is proposed. This involves a change in conformation of the cellobiose unit to permit an intramolecular hydrogen bond between the C3 hydroxyl and the ring oxygen of contiguous glucose units. Two sets of intermolecular hydrogen bonds are proposed: in the 101 plane the C6 hydroxyls of the antiparallel chains are joined to the bridge oxygens of the adjacent parallel chains; in the 101 plane the C6 hydroxyls of the parallel chains are hydrogen‐bonded to the bridge oxygens of the adjacent antiparallel chains.

The infrared spectrum of uniplanarly oriented valonia cellulose film and the polarized infrared spectra of doubly oriented films of ramie and bacterial cellulose crystallites have been observed in the region from 640 to 1700 cm.−1. The spectra have been interpreted with the assistance of band assignments in cellulose derivatives and related small molecules. Data obtained from deuterated material, band polarizations, and tilting effects have also been used. The perpendicular band at 1317 cm.−1 is assigned to the CH2 wagging mode. The highly parallel polarized band at 1162 cm.−1 is assigned to the antisymmetric bridge COC stretching frequency and the slightly parallel polarized band at 1110 cm.−1 is assigned to a ring stretching frequency. The interpretations of the other observed bands are discussed generally.

The infrared spectrum of polystyrene has been obtained in the region of 70 cm.−1 to 3200 cm.−1. These data, plus Raman scattering data from the literature, are used to make a complete assignment of the normal modes of the polystyrene molecule. The benzene ring modes have been analyzed in detail in terms of C2v symmetry, and a set of normal vibrations has been proposed. On the basis of previous analyses of the benzene and monosubstituted benzenes, and a study of the combination bands, it has been possible to make a fairly satisfactory assignment of all of the benzene ring fundamentals. Assignments of the CH2, CH, and skeletal modes are made on the basis of previous studies of spectra of high polymers. The interpretation of the spectrum is in agreement with other evidence that the chain configuration is a random one, i.e., that the polymer is amorphous.

A novel strategy was designed to prepare Ag cluster-doped TiO(2) nanoparticles (Ag/TiO(2) NPs) without addition of any chemical reducing agent and/or organic additive. A defect-rich TiO(x) species was generated by laser ablation in liquid (LAL) of a Ti target. The silver ions could be reduced and deposited on the surface of TiO(2) NPs through the removal of oxygen vacancies and defects; the TiO(x) species evolved into anatase NPs in a hydrothermal treatment process. The derived Ag/TiO(2) NPs are approximately 25 nm in size, with narrow size distribution. The Ag clusters are highly dispersed inside TiO(2) and less than 3 nm in size. The doped amount can be tuned by changing the concentration of Ag(+) ions. The as-synthesized Ag/TiO(2) NPs display improved photocatalytic efficiency toward pentachlorophenol (PCP) degradation.

The infrared spectrum of polyvinyl alcohol has been investigated between 3600 and 70 cm.−1. Polarization measurements on stretched specimens were made down to about 330 cm.−1. The spectrum of a deuterated specimen (about 90% of the OH having been replaced by OD) has also been obtained. These data confirm and extend the results of previous workers. The spectrum is discussed in detail in relation to three structures for polyvinyl alcohol proposed on the basis of x‐ray diffraction studies. The data definitely rule out the structure proposed by Mooney, and are most consistent with the structure proposed by Bunn. A complete assignment of the bands in the spectrum is proposed. From this analysis it appears that the existence of interaction forces between molecules can be convincingly demonstrated. The proposed assignments suggest a new interpretation of the 1326–1446 cm.−1 doublet, viz., that these bands arise from mixed CH and OH in‐plane bending vibrations. This is shown to be in agreement with the results of studies on simple alcohols. An alternative assignment for the 1144 cm.−1 band is also considered.