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Abstract: A series of wood-fibre mats was investigated using high-resolution phase-contrast microtomography at the beamline ID 19 of the European Synchrotron Radiation Facility in Grenoble, France. A method for data reduction to quantify the degree of fibre–fibre contact has been derived. The degree of fibre–fibre contact and bonding plays a fundamental role in the mechanical properties of cellulose-fibre mats, paper materials and cellulose-fibre composites. The proposed computerised automated method consists of two parts. First, fibre lumens are segmented using a watershed based method. This information is then used to identify fibre–fibre contacts in projections along the z-axis of the material. The method is tested on microtomographic images of mats made of wood pulp fibres, and is shown to successfully detect differences in the amount of fibre–fibre contact between samples. The degree of fibre–fibre contact correlates well with measured out-of-plane strength of the fibrous material. [Copyright &y& Elsevier]

The surface properties of paper depend not only on the fibrous matrix but also on the final treatment of the paper surface. The present work compares paper samples with two different surface sizing treatments by using AFM and profilometry to assess topography and roughness parameters as well as to evaluate the spreading of the sizing formulation and to estimate sizing agent particle sizes. The results were confronted with dynamic light scattering measurements regarding particle size. This work shows that AFM is a valuable technique to visualize and quantify the effects of sizing on the paper surface. Due to the small amount of surface sizing applied, no significant differences between the surface sized samples and the reference sample (without surface treatment) could be detected in terms of the surface roughness parameters. Nonetheless, those of sample B1 are systematically smaller than those of sample A1. [ABSTRACT FROM AUTHOR]

The basic types of polymer composite materials (PCMM) made from different kinds of reinforcing fibre fillers: short-cut fibres, paper, yarns, tow, sliver, fabrics, and nonwovens, and their properties and use are examined. Information on the fabrication and properties of the different kinds of composites are reported: extruded fibre plastics, getinaxes, textolites, unidirectional composites, honeycomb plastics, and others. New kinds of composites with ultrahigh mechanical and thermal characteristics are also examined. Some of the reported information was previously covered very sparely in the literature. Based on the examination, the features of polymer fibre composites are summarized in comparison to other materials, and they can be summarized as the following basic points: 1) combining different kinds of fibre fillers and matrices (binders) allows fabricating PCM with a wide range of properties by selecting the optimum indexes for articles with a broad spectrum of applications; 2) articles made of fibre PCM are not very materials-intensive and are technologically effective for processing in comparison to many traditional materials, metals and ceramics in particular; 3) with respect to the specific mass characteristics, fibre PCM can be many times superior to articles made of traditional materials—metals, etc., so that the mass (weight) characteristics of articles made of fibre composites can be significantly reduced, which is especially important for using them in vehicles, aircraft, rescue equipment, and sporting goods; 4) articles made of composites have high performance reliability, are almost immune to corrosion, and do not require special protection or periodic painting of the surface. Due to the features of the properties and use, fibre PCM have a great future in the most varied areas of application. [ABSTRACT FROM AUTHOR]

The general method of producing fluorescent paper by coating fluorescent substances onto paper base faces the problems of low efficiency and poor durability. Bacterial cellulose (BC) with its nanoporous structure can be used to stabilize fluorescent particles. In this study, we used a novel method to produce fluorescent paper by first making Eu/BC complex and then processing the complex and cellulosic fibers into composite paper sheets. For this composting method, BC can form very stable BC/Eu complex due to its nanoporous structure, while the plant-based cellulosic fibers reduce the cost and provide stiffness to the materials. The fluorescent paper demonstrated a great fluorescent property and efficiency. The ultraviolet absorbance or the fluorescent intensity of the Eu-BC fluorescent paper increased with the increase of Eu-BC content but remained little changed after Eu-BC content was higher than 5%. After folding 200 times, the fluorescence intensity of fluorescent paper decreased by only 0.7%, which suggested that the Eu-BC fluorescent paper has great stability and durability. [ABSTRACT FROM AUTHOR]