Structural and Nanomechanical Properties of Paperboard Coatings Studied by Peak Force Tapping Atomic Force Microscopy

ArticleinACS Applied Materials & Interfaces 4(10):5534-41 · September 2012with9 Reads
DOI: 10.1021/am301439k · Source: PubMed
Paper coating formulations containing starch, latex, and clay were applied to paperboard and have been investigated by scanning electron microscopy and Peak Force tapping atomic force microscopy. A special focus has been on the measurement of the variation of the surface topography and surface material properties with a nanometer scaled spatial resolution. The effects of coating composition and drying conditions were investigated. It is concluded that the air-coating interface of the coating is dominated by close-packed latex particles embedded in a starch matrix and that the spatial distribution of the different components in the coating can be identified due to their variation in material properties. Drying the coating at an elevated temperature compared to room temperature changes the surface morphology and the surface material properties due to partial film formation of latex. However, it is evident that the chosen elevated drying temperature and exposure time is insufficient to ensure complete film formation of the latex which in an end application will be needed.
    • "The main properties of a paper depend not only on the type of cellulosic fibers, but also on the application of fillers and additives, which ensure good control over the final product. In recent years, investigations in papermaking processes are connected with the progress in nanostructural investigations and with the use of nanoparticles in paper compositions123. This approach is reasonable for economic and environmental reasons. "
    [Show abstract] [Hide abstract] ABSTRACT: The modern and rapidly developing paper and board industry requires more efficient agents for the surface of paper in order to improve the mechanical properties. The starch coating used for the reinforcement of schrenz (110 g/m2) contained ultrasonicated nanoparticles of the mineral sepiolite. The viscosity of starch dispersions modified with different concentration of sepiolite was followed at the temperature of the coating on schrenz. The values of the breaking length, bursting strength and CMT-strength of the paper reinforced with modified starch were increased by up to 20 %. The viscoelastic properties as storage modulus were increased, too. Scanning electron microscopy of the samples showed deagglomeration and homogeneity of the sepiolite nanoparticles.
    Full-text · Article · Dec 2014
    • "Recently, a new atomic force microscopy (AFM) based technique , PeakForce Ò Quantitative Nanomechanical Property Mapping (PF-QNM), has made possible mapping of physical and mechanical properties of the surface in addition to topography [10,11]. In the PeakForce Ò measurement [10,11], the piezo scanner makes the sample oscillate, resulting in force vs. separation data generated in every ''tap''. From the resulting force curves, contact mechanical and surface properties such as adhesion are pixelwise obtained, with a nanometer-scale lateral resolution12131415. "
    [Show abstract] [Hide abstract] ABSTRACT: The adhesion properties of a FeCrVN experimental tool alloy immersed in pure water and sodium chloride solution have been studied by Quantitative Nanomechanical Property Mapping to understand the influence of microstructure on corrosion initiation of this alloy. The approach used here allows early observation and identification of pre-pitting events that may lead to passivity breakdown of the alloy. Adhesion provides a good distinction between the different regions and we ascribe this to their vanadium and nitrogen contents. Finally, the prepitting is characterized by generation of small particles in specific regions of the surface with low chromium content.
    Full-text · Article · Aug 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Efficient lubricants should be able to build surface layers that result in low friction and high load bearing capacity. In this work we show how this can be achieved in aqueous media by means of adsorption of a diblock copolymer consisting of a cationic anchor block without side chains and an uncharged and hydrophilic bottle-brush block that protrudes into solution. Surface and friction forces were measured between negatively charged silica surfaces coated with adsorbed layers of the cationic diblock copolymer, utilizing the atomic force microscope colloidal probe technique. The interactions between the surfaces coated with this copolymer in water are purely repulsive, due to a combination of steric and electrostatic double-layer forces, and no hysteresis is observed between forces measured on approach and separation. Friction forces between the diblock copolymer layers are characterized by a low friction coefficient, μ ≈ 0.03–0.04. The layers remain intact under high load and shear due to the strong electrostatic anchoring, and no destruction of the layer was noted even under the highest pressure employed (about 50 MPa). Addition of NaCl to a concentration of 155 mM weakens the anchoring of the copolymer to the substrate surface, and as a result the friction force increases.
    Full-text · Article · May 2013
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