Spin-bonding process

The polyethylene fibers may be made by a spin-bonding process, which involves rapid spinning and solvent evaporation. Although the fibers are not as uniform as required for textile uses, they are much more economical when produced in this way. 

As briefly stated in the introduction, we may consider one-dimensional cross sections through the zero-order potential energy surfaces for the two spin states, cf. Fig. 9, in order to illustrate the spin interconversion process and the accompanying modification of molecular structure. The potential energy of the complex in the particular spin state is thus plotted as a function of the vibrational coordinate that is most active in the process, i.e., the metal-ligand bond distance, R. These potential curves may be taken to represent a suitable cross section of the metal 3N-6 dimensional potential energy hypersurface of the molecule. Each potential curve has a minimum corresponding to the stable... 

A factor associated with the covalent bonding process is that the spins of the bond-forming electrons, which are unpaired in separate atoms, become paired during the bond formation. 

Agreement between theoretical and experimental TJT2 values is much poorer for X = Br and I and indicates a breakdown of the Redfield theory. (32) Isotropic proton shifts for pyridine-N-oxide and y-picoline-A-oxide protons have been reported in the 5-coordinated adducts of these bases with bis(di-p-tolyl-dithiophosphinato)-Co(ii) and -Ni(ii). (70,71) Dipolar shifts have been evaluated and indicate that the Co(ii)-pyridine-N-oxide adducts have a bent structure in solution with Co-O-N angle of 125°. Results indicate that a rr-spin delocalization mechanism is operating, and INDO calculations suggest that the highest bonding orbital is involved in the spin transfer process. 

The model described by Geiger et al. is consistent with conclusions of Larson et al. [60], who, on the basis of molecular orbitals (MO) calculations, tried to explain why benzyl acetates and halides undergo heterolysis from T, and benzyl-ammonium structures from Sj. They found that immediately before dissociation, as the C-X bond elongates, the state rapidly approaches the ncr state in the case of acetates and halides and in the case of ammonium salt because there is no lone pair of electrons in the latter structure. It was suggested that an efficient spin inversion process leads to ion pair formation from the nci state, and no such channel for the cnr state exists. 

According to [6], in singlet pairs formed by defects, i.e. in structural defect nanoclusters, the UHF field also stimulates intercombinative transitions or a singlet-triplet (S-T) conversion which leads to weakening and disruption of chemical bonds in a PDC. We can assume that in our case we deal with the UHF-field-induced change of spin orientation and subsequent disruption of chemical bonds in complexes of oxide precipitates (like SiOx in silicon). Probably, spin-dependent processes can also occur in other complexes, for... 

The typical spun-bonding process includes a spinneret with a means of conveying the continuous filaments out into the form of a web, or else several spinnerets arranged in a row whose length may approximate the width of the web to be produced. In either case, the process of melting and fiber formation is identical to that used in conventional melt spinning. 

The part assembly design addresses the ability to join/assemble the component parts. Where the components are assembled with adhesives, it is important to know the compatibility and strength of adhesion to dissimilar substrates, in addition to the chemical compatibility of the plastic with the specific adhesive and its constituents. If melt bonding methods, like ultrasonic, vibration, or spin-welding processes, are employed, thermal compatibility aspects have to be taken into account. The broad possibilities of mechanical assembly methods include snap fits, press fits, bolts, and threads. The material properties needed for each of these design calculations are listed in Table 11.9. 

Waterproof modified Silicone strrface was exploit for the self-assembly-driven growth due to H-bonding of complexes NF(acac)2xNaSt(or List) xPhOH with Silicone surface. The saturated chloroform (CHClj) solution of complex NF(acac)2xNaSt(or LiSt)xPhOH (1 1 1) was put on a surface, maintained some time, and then solvent was deleted from a surface by means of special method - spin-coating process. 

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