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This article presents a novel method for integrating native corn starch and calcium carbonate (CaCO 3 ) into a hybrid pigment, which can be applied in papermaking to increase the amount of starch in paper and improve sheet bonding without impairing dewatering. Starch was first thermally treated to partially gelatinize and swell the granules. The aim of the treatment was to change the surface properties of starch and thus to improve the interaction with CaCO 3 particles. CaCO 3 shell was precipitated around the swollen granules and the encapsulated starch was then cooked to achieve complete gelatinization. When the granules were cooked, the starch became active for bonding, but its solubility was very limited due to the encapsulation. Particle size measurement and scanning electron microscopy were used to analyze the sample properties during the preparation. The hybrid pigment was added to paper sheets and its effect on the paper properties was examined. Starch was shown to be effectively bound to the pigment structure. The hybrid pigment allowed a large amount of native corn starch to be added to paper without interfering with the papermaking process. Furthermore, it gave excellent mechanical paper properties. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the feasibility of using highly filled powders with 100 parts per weight of calcium carbonate and 10 parts per weight of polymer, acting as binder, as electrostatically applied paper coatings. Such powders prepared by different methods were evaluated as being suitable for electrostatic coating. Powders compacted at elevated temperatures demonstrated cohesion superior to that of calcium carbonate, and at best similar to that of aqueous coatings. Cohesion, porosity and thus absorption properties of compacted powders were affected by the powder preparation method, compaction process, and powder composition. Powders containing semicrystalline polymer turned out to be the most interesting for further testing. [ABSTRACT FROM AUTHOR]

Abstract: The commercially available copy papers and pure papers have been adopted to synthesize carbon nanomaterials. It is found that carbon nanocoils (CNCs) are efficiently synthesized on the copy paper substrates using Fe2(SO4)3/SnCl2 catalyst by a thermal chemical vapor deposition method, while only carbon nanotubes (CNTs) are obtained on the pure paper substrate using the same process. It is evidenced that the particles of calcium carbonate existing in copy paper aggregate catalyst and adsorb more sulfur elements which promote the growth of CNCs. In addition, CNCs can successfully grow out from the pure paper by adding calcium carbonate. [Copyright &y& Elsevier]

Abstract: Nanoscaled surface roughness with a hydrophobically modified surface has been widely used for preparation of superhydrophobic materials. However, the complicated procedure, high cost and harmful compounds used in most superhydrophobic surface modifications limited their applications. This research aims at fabricating superhydrophobic cellulosic or semi-superhydrophobic papers with low cost and nontoxic materials. Commercial PCC (precipitated calcium carbonate) particles, hydrophobic stearic acid and polymer latex particles were used for surface roughness control, surface hydrophobic modification agent, and polymer binder, respectively. A simple coating or dipping method was used to produce high contact angle and high water resistance papers. It was found that the surface pretreatment of PCC with fatty acid salt prior mixing with polymer binder plays important role for improving the water contact angle (WCA). The combination of surface coating with dipping treatment will further increase the water contact angle and water resistance of the paper. A WCA near 150° over modified paper surface has been achieved. At the same degree of water resistance, the total cost of the paper can be significantly reduced by our method. [Copyright &y& Elsevier]