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Monolayers cast films

The PP monolayer cast film was processed using a ThermoHaake PolyLab extruder (RC300P/R600) with a cast film die the processing conditions are shown in Table 2. [Pg.1971]

The monolayer cast film and the multilayer cast film were measured and cut to produce prototype pouches for subsequent retort processing the dimensions of the pouches were 19.05 x 6.98 cm. The pouches were filled with distilled water and vacuum sealed to simulate the retortable MRE pouches which are filled with food products and retorted to sterilize the products inside. The retort machine used was the Validator 2000 Vertical Water and Steam Retort, which cooked the pouches for 30 minutes at 121°C. [Pg.1971]

The electrochemical behavior of the C70 solvent-cast films was similar to that of the C60 films, in that four reduction waves were observed, but some significant differences were also evident. The peak splitting for the first reduction/oxidation cycle was larger, and only abont 25% of the C70 was rednced on the first cycle. The prolate spheroidal shape of C70 is manifested in the II-A isotherm of C70 monolayers. Two transitions were observed that gave limiting radii consistent with a transition upon compression from a state with the long molecnlar axes parallel to the water snrface to a state with the long molecnlar axes per-pendicnlar to the water surface. [Pg.109]

The implications for films cast from mixtures of enantiomers is that diagrams similar to those obtained for phase changes (i.e., melting point, etc.) versus composition for the bulk surfactant may be obtained if a film property is plotted as a function of composition. In the case of enantiomeric mixtures, these monolayer properties should be symmetric about the racemic mixture, and may help to determine whether the associations in the racemic film are homochiral, heterochiral, or ideal. Monolayers cast from non-enantiomeric chiral surfactant mixtures normally will not exhibit this feature. In addition, a systematic study of binary films cast from a mixture of chiral and achiral surfactants may help to determine the limits for chiral discrimination in monolayers doped with an achiral diluent. However, to our knowledge, there has never been any other systematic investigation of the thermodynamic, rheological and mixing properties of chiral monolayers than those reported below from this laboratory. [Pg.68]

It has been shown by Harvey et al. (1989) that incorporation of palmitic acid into a monolayer spread from stearoylserine methyl ester (SSME) breaks up intermolecular SSME interactions. The palmitic acid acts as a two-dimensional diluent. Figures 52(A-C) give the Yl/A isotherms for mixtures of FE and SE C-15 6,6 -A with palmitic acid. Dilution of the monolayer cast from the second eluting isomer with 15 mol% palmitic acid separates the diacid molecules from one another on the water surface and perhaps allows for the expression of their stereochemically dependent conformations. The mixed film (15% palmitic acid/85% C-15 6,6 -A) expands at low II and behaves in much the same manner as the single-component monolayer (C-15 6,6 -A) behaves at 30°C. Addition of 15 mole% palmitic acid into a monolayer cast from the FE C-15 diacid has little effect on its energetics of compression, indicating a stronger intermolecular interaction afforded by its stereochemically dependent conformation at the air-water interface. [Pg.130]

Organic compounds which show reversible color change by a photochemical reaction are potentially applicable to optical switching and/or memory materials. Azobenzenes and its derivatives are one of the most suitable candidates of photochemical switching molecular devices because of their well characterized photochromic behavior attributed to trans-cis photoisomerization reaction. Many works on photochromism of azobenzenes in monolayers LB films, and bilayer membranes, have been reported. Photochemical isomerization reaction of the azobenzene chromophore is well known to trigger phase transitions of liquid crystals [29-31]. Recently we have found the isothermal phase transition from the state VI to the state I of the cast film of CgAzoCioN+ Br induced by photoirradiation [32]. [Pg.72]

Film adhesives, 25 582-583. See also Monolayer blown-film extrusion Multilayer blown-film extrusion Multilayer cast-film extrusion... [Pg.358]

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. [Pg.288]

The self-assembling character of bilayer membranes is demonstrated by the formation of free-standing cast films from aqueous dispersions of synthetic bilayer membranes. The tendencies for association are sufficiently strong to allow the addition of guest molecules (nanoparticles, proteins, and various small molecules) to these films where the connective forces are secondary in nature and not primary. Synthetic polymer chemists have made use of these self-assembling tendencies to synthesize monolayer films. In particular, a monomer that contains both reactive groups and hydrophobic and hydrophilic areas is cast onto an appropriate template that self-assembles the monomer, holding it for subsequent polymerization. Thus, a bilayer structure is formed by... [Pg.505]

Description of the different mimetic systems will be the starting point of the presentation (Sect. 2). Preparation and characterization of monolayers (Langmuir films), Langmuir-Blodgett (LB) films, self-assembled (SA) mono-layers and multilayers, aqueous micelles, reversed micelles, microemulsions, surfactant vesicles, polymerized vesicles, polymeric vesicles, tubules, rods and related SA structures, bilayer lipid membranes (BLMs), cast multibilayers, polymers, polymeric membranes, and other systems will be delineated in sufficient detail to enable the neophyte to utilize these systems. Ample references will be provided to primary and secondary sources. [Pg.11]

Monolayer casting experiments made use of similar experimental conditions to form organized and highly compressed membranes. Such films were deposited on polyacrylamide gel by dipping the polymer through the air-water interface of the trough, with monolayer compression held constant at pressures of 30 to 40 mN.m". ... [Pg.354]

Some the structural state of dendritic macromolecules at air - water (Langmuir monolayers) and air - solid (adsorbed monolayers, self - assembled films, and cast films) interfaces has been discussed by V. V. Tsukruk [106] and Frechet [107],... [Pg.229]

The monolayer also provides an environment of variable dielectric so that intermolecular association between photoactive molecules can readily occur. For example, molecular association of pyrene within a Langmuir-Blodgett film is clearly seen through time-resolved fluorescence measurements on the picosecond timescale [92], Attenuated total reflectance studies of dyes in cast films can similarly reveal their positions and photophysical interactions [93], Photochromism in a monolayer assembly has been attributed to excitation of ion-pair charge transfer complexes formed within the array [94]. [Pg.89]

The organic thin films used in lithography are polymer casting films, Langmuir-Blodgett (LB) films, SAMs and plasma-polymerized films. The molecular designs and syntheses of organic monolayer materials are studied for SPNL resists [89]. [Pg.159]

SBC film is growing into more and more film applications. It is proving to be well suited for fresh cut produce packaging, candy twist wrap, shrink films, flexible medical and decorative films. SBC can be extruded into either cast or blown film for use in flexible packaging applications. While some applications employ a monolayer SBC film, many films are co-extruded with SBC along with several layers of other materials in order to bring a combination of properties to the final application. [Pg.514]

Organized azo-molecular assemblies allow for the study of photoisomerization and photo-orientation in sterically and orientationally well-defined media, such as LBK multilayers, the molecular-interactions-based order of which can be altered by photoisomerization of the azo units.In this chapter, we also discuss the photoisomerization-induced changes in the structural and optical properties of highly organized organic films containing azobenzenes. Photoisomerization and photo-orientation of azobenzenes is compared in amorphous spin-cast films, in LBK supramolecular assemblies, and in self-assembled monolayers. [Pg.110]

In solution-deposited fihns on dielectrics, the crystalline orientation and morphology depend considerably on polymer-substrate interaction, which can be controlled by modification of the dielectric surface with a self-assembled monolayer (SAM). Cho et al. have controlled the intermolecnlar interaction at the interface between HT-PHT and the dielectric substrate by using SAMs functionalized with various groups (-NH2, -OH, and -CH3) [24]. They have found that, depending on the properties of substrate surface, HT-PHT nanocrystals in the spin-cast films adopt two different orientations of 7t-conjugated planes — parallel and perpendicular to the substrates. These have field-effect mobilities that differ by more than a factor of four and are as high as 0.28 cm V s for jt-conjugated planes parallel to the substrates. [Pg.392]

Polymerization of these films was carried out with tricosanoyl-10 12-diynoic acid creating a red (less ordered) and blue (more ordered) form. Bulk polymerized films were observed at the air/water interface and on glass substrates though with slightly differing intensities in their visible absorption spectra. It was clear that when monolayer films were polymerized and then compressed beyond the collapse point, the resultant film was significantly less ordered, as indicated by the predominance of the red conformer. Thus the molecular order of a polymerized film can be adversely affected by subsequent mechanical manipulation. In contrast to monolayers, solution cast films showed no polymerization under comparable conditions, but did do so once the film had been annealed. It would appear that annealing allowed the formation of a better oriented film. [Pg.699]

The elastomeric nonweave that was invented comprises a monolayer of elastomeric film and two layers of special elastic nonweaves. The monolayer elastomeric film comprises 90% VISTAMAXX 1100 polyolefinic elastomer firom ExxonMobil Chemical, 5% ELITE 5800 linear low density polyethylene from Dow Chemical Company, and 5% white master-batch concentrate (Schulman 8500) firom Schulman Corporation. The elastomeric monolayer films were extruded on a cast-extrusion line. The basic weight of elastomeric film is about 14 to 20 g with basis weight fluctuation of less than 20%. These films were bonded with ultrasonic waves to two layers of... [Pg.64]

The 9-BCMU multilayer films show more subtle differences in the degree of order and conjugation, when prepared differently. The solution-cast film, when polymerized by u.v. light, shows the least order (X = 635 nm) for a blue form. When a 9-BCMU monomer monolayer film is polymerized at the air-water interface, and then transferred to a substrate, it shows a greater degree of order and conjugation (X = 645 nm). The most ordered polymerized multilayer film is obtained when the monomer is first transferred as a multilayer and then polymerized (X = 655 nm). [Pg.575]

Fukuda, K., T. Seki, and K. Ichimura. 2002. Photoalignment of poly(di-M-hexylsilane) by azobenzene monolayer. 1. Preparative conditions of poly(di-n-hexylsilane) spin cast film. Macromolecules 35 2177. [Pg.751]


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See also in sourсe #XX -- [ Pg.172 ]




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Monolayer films

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