Films self-assembled

Lenk T J, Hallmark V M, Rabolt J F, Haussling L and Ringsdorf H 1993 Formation and characterization of self-assembled films of sulphur-derivatized poly(methyl methacrylates) on gold Macromolecules 26 1230-7... 

It is interesting to compare the thermal-treatment effect on the secondary structure of two proteins, namely, bacteriorhodopsin (BR) and photosynthetic reaction centers from Rhodopseudomonas viridis (RC). The investigation was done for three types of samples for each object-solution, LB film, and self-assembled film. Both proteins are membrane ones and are objects of numerous studies, for they play a key role in photosynthesis, providing a light-induced charge transfer through membranes—electrons in the case of RC and protons in the case of BR. 

The fact that CD spectra of BR in LB and self-assembled films show similar behavior with respect to temperamre is also not strange. Because the basic block of the fihn in both cases is the membrane fragment, which is already closely packed, there is no principal difference between these samples with regard to packing. The difference in the distribution of these fragments cannot be critical for thermal stability. 

In the case of RC there are big differences in the temperature dependencies of CD spectra of LB and self-assembled films. The differences are due to the different organization of molecular structures in the fihn. In the case of self-assembled films, the molecules... 

Interest in the adsorption of sulfur-containing molecules at metal surfaces been stimulated by a desire to elucidate the decomposition mechanisms of thiols during the catalytic removal of sulfur from feedstocks and the position of thiols as the favoured head groups for adsorbates used to construct self-assembled monolayers. We shall not survey the extensive self-assembled film literature but restrict our discussion to the simpler thiols. 

Moreover, it has been demonstrated that CNTs promote the direct electrochemistry of enzymes. Dong and coworkers have reported the direct electrochemistry of microperoxidase 11 (MP-11) using CNT-modified GC electrodes [101] and layer-by-layer self-assembled films of chitosan and CNTs [102], The immobilized MP-11 has retained its bioelectrocatalytic activity for the reduction of H202 and 02, which can be used in biosensors or biofuel cells. The direct electrochemistry of catalase at the CNT-modified gold and GC electrodes has also been reported [103-104], The electron transfer rate involving the heme Fe(III)/Fe(II) redox couple for catalase on the CNT-modified electrode is much faster than that on an unmodified electrode or other... 

Molecular calculations provide approaches to supramolecular structure and to the dynamics of self-assembly by extending atomic-molecular physics. Alternatively, the tools of finite element analysis can be used to approach the simulation of self-assembled film properties. The voxel4 size in finite element analysis needs be small compared to significant variation in structure-property relationships for self-assembled structures, this implies use of voxels of nanometer dimensions. However, the continuum constitutive relationships utilized for macroscopic-system calculations will be difficult to extend at this scale because nanostructure properties are expected to differ from microstructural properties. In addition, in structures with a high density of boundaries (such as thin multilayer films), poorly understood boundary conditions may contribute to inaccuracies. 

J. Tian, C.-C. Wu, M.E. Thompson, J.C. Strum, and R.A. Register, Photophysical properties, self-assembled films, and light-emitting diodes of poly(p-pyridylvinylene)s and poly(p-pyridinium vinylene)s, Chem. Mater., 7 2190-2198, 1995. 

This chapter describes the use of AFM as a methodology for characterizing dendritic macromolecules and their self-assembled films. Systematic AFM studies of the PAMAM dendrimers properties (e.g. their size, shape, rigidity, packing textures and molecular weight calculations) will be fully addressed in this chapter. 

The structural state of dendritic macromolecules at air-water (Langmuir mono-layers) and air-solid (adsorbed monolayers, self-assembled films and cast films) interfaces have been reviewed by Tsukruk [17]. Although this work summarizes various characterization techniques for dendritic films by AFM techniques, in this chapter, we will present recent progress on the characterization of the dendritic film surface morphologies. 

Depending on the strength and type of interaction between the dendrimer and the surface, they can flatten out almost completely. Although the unique spherical shape of the dendrimer is very often lost in self-assembled films, other specific properties such as multifunctionality, porosity etc. are retained. This important feature has led to the birth of a new and exciting area of research functional dendritic surfaces, which will be discussed in the next section. 

Pinto MR, Rristal BM, Schanze KS (2003) A water-soluble poly(phenylene ethynylene) with pendant phosphonate groups. Synthesis, photophysics, and layer-by-layer self-assembled films. Langmuir 19 6523-6533... 

Li CY, Wang CF, Wang CH, Hu SS. Development of a parathion sensor based on molecularly imprinted nano-Ti02 self-assembled film electrode. Sens Actual B 2006 117 166-171. 

Some bioelectrochemical applications of self-assembled films on mercury (including among others, chlorophyll and... 

Neutral. A bis(ethylenediamine) structure has been incorporated into the surfactant molecule -Ci6H33C(H)[CON(H)(CH2)2NH2]2 in older to incorporate metal ions in an LB film structure via coordination instead of ionic complexation as occurs for anionic/cationic amphiphiles (14). Also, films of n-octadecylacetoacetate containing Cu2+ have been prepared, and exposure to H2S has resulted in the formation of a copper sulfide (39). Ditetradecyl-A-[4- [6-(A, N, W -trimethyl-ethylenediamino)-hexyl]oxy]benzoyl]-L-glutamate (DTG), which also contains the ethylenediamine unit, was used to make self-assembled films containing Cd2+ (40). 

Although not strictly LB films, there are other types of self-assembled films containing Q-state MCs that resemble LB films. One example involves the self-assembly of the amphiphile DTG into an organized film by slow evaporation of solvent from a dispersion of the amphiphile (40). The structure of the cast film has the head-... 

UV/visible absorbance measurements of H2S-exposed M-FA films (M = Cd or Hg) have provided information about reaction rates. Delineation of the two processes depicted in Eq. (7) and (8) is difficult, however, as they can occur simultaneously. The reactions of LB films (CdAr) and cast self-assembled films of the cadmium salt of ditetradecyl-iY-[4-([6-/V, Ar, Ar -trimelhylethylenediamino)-hexyI oxy) benzoyl]-L-glulamate (Cd(DTG)2) with H2S have been followed by time-resolved UV/visible absorbance (85). The most profound observation from this investigation is with respect to the effect that water has on the rate of growth of the CdS particles... 

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