Substrate choice

Adhesion depends on a number of factors. Good adhesion is defined by most customers as substrate failure. The major adhesive manufacturers possess equipment that allows them to make bonds with customer substrates under conditions that closely simulate actual packaging lines. These bonds are peeled either automatically or by hand to gauge adhesion. The most important factors influencing adhesion are the wet-out of the substrate, partieularly by the polymer component of the adhesive system, and the specific adhesion with the substrate. Choice of resin is critical for both. Rosin, rosin esters and terpene phenolics are eommonly added for these purposes in EVA and EnBA-based systems. Adhesion at low temperatures is also influenced by the overall toughness of the system at the test temperature. 

Another example of the use of modelling to consider substrate choice can be found in Lafyatis et al. (2000). 

As the concentration of BH increases, the observed catalytic coefficient will decrease until, when 2[BH] > k, the catalytic coefficient equals ,[OH ] and the rate-determining step is the addition of hydroxide ion to the substrate. Choice may be made between a number of unsymmetrical mechanisms depending upon the rate dependence upon hydrogen ion, hydroxide ion or water concentrations at high buffer concentrations or [B] or [BH] at low buffer concentrations. Johnson has tabulated the 18 kinetic possibilities and the 13 different types of kinetic behaviour of general acid-base-catalysed reaction, pointing out that this tabulation uses only one ionic form for the tetrahedral intermediate. 

Up to date, besides the SFA, several non-interferometric techniques have been developed for direct measurements of surface forces between solid surfaces. The most popular and widespread is atomic force microscopy, AFM [14]. This technique has been refined for surface forces measurements by introducing the colloidal probe technique [15,16], The AFM colloidal probe method is, compared to the SFA, rapid and allows for considerable flexibility with respect to the used substrates, taken into account that there is no requirement for the surfaces to be neither transparent, nor atomically smooth over macroscopic areas. However, it suffers an inherent drawback as compared to the SFA It is not possible to determine the absolute distance between the surfaces, which is a serious limitation, especially in studies of soft interfaces, such as, e.g., polymer adsorption layers. Another interesting surface forces technique that deserves attention is measurement and analysis of surface and interaction forces (MASIF), developed by Parker [17]. This technique allows measurement of interaction between two macroscopic surfaces and uses a bimorph as a force sensor. In analogy to the AFM, this technique allows for rapid measurements and expands flexibility with respect to substrate choice however, it fails if the absolute distance resolution is required. 

Plasmonic nanostructures that are materials consisting of noble metal nanoparticles with sizes of 1-100 nm are known as specific substrates for surface enhanced Raman scattering and luminescence enhancement [1-4]. These effects are stimulated by the localized surface plasmon absorption (LSPA) and may be controlled by the change of metal nanoparticle sizes, their concentration and a substrate choice [5]. New opportunities for surface-enhanced effect realization and optimization are now discussed in connection with bimetallic nanostructures [6]. At the technological aspect one of the simplest types of a binary nanostructure is a stratified system made of two different monolayers, each is consisted of definite metal nanoparticles. The LSPA properties of these binary close-packed planar nanostructures are the subject of the paper. 

Preparation of the samples included the following steps, surface modification of the substrate, polymer film deposition, thermal annealing, and selective degradation of the PLA phase, as illustrated in Fig. 4.1. The PLA removal does not alter the copolymers morphology and is comparatively easy, whereas the substrate choice, the surface modification, and thermal annealing protocol decisively influence the copolymer self-assembly behavior as will be discussed in the context of polymer phase separation [2,3]. The vast possible parameter space of the latter two preparation steps, combined with the numerous copolymers, presented a real challenge. 

Mixed populations of microorganisms (Aris and Humphrey, 1977 Jannasch and Mateles, 1974 Yoon and Blanch, 1977) occur, for example, in waste water treatment, in which the variation of organism composition with time plays a central role. The connection between various environmental circumstances (such as substrate choice and organism species composition) is shown in Figs. 5.54 and 5.55. 

High-temperature requirements may limit substrate choices... 

Acyloins (la) [29,30] and bis-silylated derivatives of their enediols (lb) [31] have been demonstrated to be useful acyl anion equivalents (RCO ) and have been employed in an indirect but facile way for the preparation of ketones (3) (Equation 7.1). The hydroxy ketones (2), which are the key intermediates in this method, have been prepared by the reaction of acyloins (la) with organic halides in the presence of sodium hydroxide in dimethyl sulfoxide [29, 30] according to the Hein s procedure [32] or using sodium hydride in 1,2-dimethoxyethane (DME) (glyme) [33]. They also have been prepared by the alkylation of lithium enedi-olates of acyloins prepared from the corresponding lb and methyllithium [31]. These reactions proceed with C-alkylation however, the reaction conditions employed are quite basic which would limit substrate choice. 

In the view of the above presentation, it appears that each aerosol-assisted deposition process has its advantages and drawbacks in terms of complexity of implementation and quality of deposit. In particular, AACVD could be a suitable alternative to produce homogeneous and optical grade films of controlled thickness. However, this technique involves a rather high deposition temperature, which restrains the substrate choice. Furthermore, some limitations exist when volatile or thermally decomposable precursor compounds are not available. Such limitations could be overcome by the implementation of an AASG deposition technique. 

Butman, C.A., J.P. Grassle C.M. Webb. 1988. Substrate choices made by marine larvae settling in still water and in a flume flow. Nature 333 771-773. 

The variety of substrate choices for the Biginelli reaction and its good tolerance to many functional groups offers the opportunity to use it in cooperation with other reactions in one pot. In addition, the wide choices of reaction temperature, catalysts, and solvents for the Biginelli reaction are also helpful in matching with the polymerization process. 

In terms of substrate choice, C9 amino derivatives of the cinchona alkaloids have proven to be suitable for sterically hindered a-branched aldehydes, a-branched unsaturated aldehydes, as well as simple unsaturated ketones and a-branched enones. In general terms, catalysis with the C9 amino derivatives can involve... 

Substrate Choice Molding Process Primer Choice Basecoal Clearcoat... 

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