FIBER ORIENTATION DISTRIBUTION OF PAPER SURFACE CALCULATED BY IMAGE ANALYSIS

Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.

Preparation and characterization of tea tree oil-β-cyclodextrin microcapsules with super-high encapsulation efficiency

This study aimed to prepare tea tree oil-β-cyclodextrin microcapsules using an optimized co-precipitated method.The impact of the volume fraction of ethanol in the solvent system for microencapsulation on encapsulation efficiency was investigated and analyzed sophisticatedly.Super-high encapsulation efficiency was achieved when a 40%volume fraction of ethanol was used for the microencapsulation procedure,where the recovery yield of microcapsules and the embedding fraction of tea tree oil in microcapsules were as high as 88.3%and 94.3%,respec-tively.Additionally,considering the operation cost,including time and energy consumption,an economical preparation was validated so that it would be viable for large-scale production.Based on the results of morphological and X-ray diffraction analysis,the crystal structure appeared to differ before and after microencapsulation.The results of gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy confirmed the successful formation of microcapsules.Furthermore,the antibacterial activity of the fabricated microcapsules was assessed by a simple growth inhibition test using Bacillus subtilis as the study object,and the hydrophilic property was proved by a water contact angle measurement.

Bioinspired cellulose-based membranes in oily wastewater treatment

It is challenging to purify oily wastewater, which affects water-energy-food production. One promising method is membrane-based separation. This paper reviews the current research trend of applying cellulose as a membrane material that mimics one of three typical biostructures: superhydrophobic, underwater superoleophobic, and Janus surfaces. Nature has provided efficient and effective structures through the evolutionary process. This has inspired many researchers to create technologies that mimic nature’s structures or the fabrication process. Lotus leaves, fish scales, and Namib beetles are three representative structures with distinct functional and surface properties: superhydrophobic, underwater superoleophobic, and Janus surfaces. The characteristics of these structures have been widely studied and applied to membrane materials to improve their performance. One attractive membrane material is cellulose, whichhas been studied from the perspective of its biodegradability and sustainability. In this review, the principles, mechanisms, fabrication processes, and membrane performances are summarized and compared. The theory of wettability is also described to build a comprehensive understanding of the concept. Finally, future outlook is discussed to challenge the gap between laboratory and industrial applications.