Atomic force microscopy latices

Nick L, Lammel R and Fuhrmann J 1995 Latex characterization by atomic force microscopy Chem. Eng. Technol. 18 310... 

Johnson, C. A. and A. M. Lenhoff. 1996. Adsorption of charged latex particles on mica studied by atomic force microscopy. /. Colloid Interface Sci. 179 587-599. 

INVESTIGATION OF LATEX PARTICLE MORPHOLOGY AND SURFACE STRUCTURE OF CORRESPONDING COATINGS BY ATOMIC FORCE MICROSCOPY... 

Latex with hydroxyl functionalised cores of a methyl methacrylate/butyl acrylate/2-hydroxyethyl methacrylate copolymer, and carboxyl functionalised shells of a methyl methacrylate/butyl acrylate/methacrylic acid copolymer was prepared by free radical polymerisation. The latex was crosslinked using a cycloaliphatic diepoxide added by three alternative modes with the monomers during synthesis dissolved in the solvent and added after latex preparation and emulsified separately, then added. The latex film properties, including viscoelasticity, hardness, tensile properties, and water adsorption were evaluated as functions of crosslinker addition mode. Latex morphology was studied by transmission electron and atomic force microscopy. Optimum results were achieved by introducing half the epoxide by two-step emulsion polymerisation, the balance being added to the latex either in solution or as an emulsion. 8 refs. 

As a first step in the study of the molar mass dependence of film formation, the rate of deformation and the spreading of individually adsorbed latex particles is measured under dry conditions using atomic force microscopy. These data recorded at different temperatures and particles with different molecular weights are compared with glass transition temperatures and minimum film formation temperatures. The preliminary results indicate that the speed of the deformation process depends on both molar mass and temperature, while the... 

The effect of the Tg of the latex on the film-formation behaviour of a series of 2-ethylhexyl acrylate/methyl methacrylate emulsion copolymers was studied. Stage 1 of fihn formation was examined using a combination of DMA and conductivity measurements. Stages 2 and 3 were investigated using calorimehic compensation, DSC, dielectric spectroscopy and atomic force microscopy. Comparison of the results from the different methods employed led to a detailed model of the film-formation process in which the temp, used relative to the minimum film-formation temp, determined the effectiveness of the processes. The relative usefulness of the techniques used in their ability to characterise the various stages in the film-formation process was assessed for these copolymer systans. 23 refs. 

No.6,23rd March 1999, p. 1715-21 LATEX BLENDS OF FLUORINATED AND FLUORINE-FREE ACRYLATES EMULSION POLYMERIZATION AND TAPPING MODE ATOMIC FORCE MICROSCOPY OF FILM FORMATION... 

Wang Y, Juhue D, Winnik MA, Leung OM, Goh MC. Atomic force microscopy study of latex film formation. Langmuir 1992 8 760-762. 

Lin F, Meier DJ. A study of latex film formation by atomic force microscopy. 1. A Comparison of Wet and Dry Conditions. Langmuir 1995 11 2726-2733. 

Atomic force microscopy has also been used to investigate the morphology of natural rubber blended films. The natural rubber and poly(methyl methacrylate) particles in the latex films can be easily distinguished and are clearly... 

The specimen preparation required for atomic force microscopy of polymers is nunimal. The ability to examine a wet specimen eliminates artifact formation due to drying and the effect of vacuum. In the case of latex samples, the measurement of the particle diameter and distribution is also enhanced by the ability to resolve fine details and to easily make digital measurements. Issues with AFM imaging relate to instrumental parameters, especially whether the AFM is in the contact or non-contact mode (see Chapter 6). Two images are shown in Fig. 5.79 of polystyrene and poly(ethyl methacrylate) (PS/PEMA) latex, imaged in the non-contact mode with a Park Autoprobe AFM. Figure 5.79A... 

In 1993, Goh, et al. (77) used atomic force microscopy to study the film formation behavior of poly(butyl methacrylate) latexes. In the early stages of film formation, the surface latex particles have a protruding structure not unlike a basket of eggs. With time, the surface smoothes via lateral diffusion. 

Acrylic Latexes Containing CAM. The ability of CAM to function as a coalescing aid for acrylic latexes was demonstrated when compared to the plasticizing effect of a commercially common cosolvent, Texanol. Atomic force microscopy (AFM) in... 

Figure 13.5 (a) Transmission electron microscopy image of the PS latex (b) Atomic force microscopy image of the POM/PU blend. 

Figure 5.117. Atomic force microscopy in the noncontact mode of an uncleaned PS/ PEMA latex (A) and a cleaned PS/PEMA latex (B). (From O. L. Shaffer [581] unpublished.)...

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