Observation and Analysis of Leather Structure Based on Nano-CT

Content: The composition, working principle and the image acquisition procedure of nano-CT were introduced. A dried piece of blue stock of chrome-tanned cattle hide was chosen for this work and a sequence of 2356 images was obtained. 3D visible digital models (5mm*3.5mm*3.5mm) of leather fiber bundle braided network (Figure 1) and the interspace between fiber bundles (Figure 2) were reconstructed. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image. Based on the 3D model, the diameter, volume, surface area and other parameters of the fiber bundles, the pore structure and inclusions were measured and calculated. Take-Away: 1. 3D visible digital model of leather fiber bundle braided network was reconstructed. 2. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image

Study on the Difference of Collagen Fibre Structure Caused by Epoxy Resin Embedding

Content: The research on Collagen that possesses unique fibre structure are reported frequently. In this paper, the cross image of leather fibre of dried wet blue cowhide embedded with and without epoxy resin were investigated with micro computed topography(MCT). The images obtained by MCT of leather fibre are original status without any damage, while the embedded leather can emerge distortion because the fibre was fixed during the solidifying and immersing of the resin. In this research, 2357 images of leather fibre were investigated on wet blue leather(original fibre) and the same piece of leather embedded by epoxy resin(embedded fibre). The area ratio of the sections from the original fibre and the embedded fibre was examined for each image. The statistic results showed that the mode of area ratio of the original fibre section to the entire fibre section is 75%, and the mode of area ratio of the embedded fibre section to the embedded fibre entire section is only 48%. The mode of the area ratio of the original fibre is obviously higher than the mode of the area ratio of the embedded fibre, that is diverse with the anticipation of fibre swelling caused by resin. The reason might be the expansion of interval space among the fibre filled with epoxy resin, otherwise the conglutination of fibre caused by the evaporation of solvent(acetone used in embedding) in the course of the resion solidifying. Likewise, it can be the adhesion of the tiny fibre with the larger fibre that will diminish the area caculated. The factors will be studied further on embedding to achieve a method with minimum deformation on cross image of fibre. Take-Away: The area ratio of cross section on embedded fibre shrunk comparing with the original fibre, that is out of anticipation of the probable swelling created by resin

Denoising and Segmentation of MCT Slice Images of Leather Fiber

Content: The braiding structure of leather fibers has not been understood clearly and it is very useful and interesting to study it. Microscopic X-ray tomography (MCT) technology can produce cross-sectional images of the leather without destroying its structure. The three-dimensional structure of leather fibers can be reconstructed by using MCT slice images, so as to show the braiding structure and regularity of leather fibers. The denoising and segmentation of MCT slice images of leather fibers is the basic procedure for three-dimensional reconstruction. In order to study the braiding structure of leather fibers in the round, the image of resinembedded leather fibers MCT slices and in situ leather fibers MCT slices were analyzed and processed. It is showed that the resin-embedded leather fiber MCT slices were quite different from that of in situ leather fiber MCT slices. In-situ leather fiber MCT slice image could be denoised relatively easily. But denoising of resin-embedded leather fiber MCT slice image is a challenge because of its strong noise. In addition, some fiber bundles adhere to each other in the slice image, which are difficult to be segmented. There are many methods of image denoising and segmentation, but there is no general method to process all types of images. In this paper, a series of computer-aided denoising and segmentation algorithms are designed for in-situ MCT slice images of leather fibers and resin-embedded MCT slice images. The fiber bundles in wide field MCT images are distributed densely, adherent to each other. Many fiber bundles are separated in one image and tightly bound in another. This brings great difficulties to image segmentation. To solve this problem, the following segmentation methods are used: Grayscale-threshold segmentation method, The region-growing segmentation method, Three-dimensional image segmentation method. The denoising and segmentation algorithm proposed in this paper has remarkable effect in processing a series of original MCT slice images and resin-embedded leather fibers MCT slice images. A series of threedimensional images based on this work demonstrate the fine spatial braiding structure of leather fiber, which would help us to understand the braiding structure of leather fibers better. Take-Away: presentation ppt, Figure

Synthesis of Chitosan Derivatives and Their Inhibition Effects on Methane Hydrates

In recent years, the study of natural polymer products such as methane hydrate inhibitors has attracted more and more attention in the scientific research field. In order to achieve environmentally friendly and economical methane hydrate inhibitors with high activity, four chitosan derivatives were successfully synthesized and their methane hydrate inhibition effects were compared with chitosan (CS) and carboxymethyl chitosan (CMCS). Under the conditions of 6 MPa, 1 °C and 400 rpm, the induction time of methane hydrate was prolonged by 7.3 times with the addition of 0.1 wt% CS. It was found that chitosan with high hydrophobicity could effectively prevent methane gas from entering the water solution and reduce the driving force of methane hydrates, resulting in the extension of hydrate induction time. The hydrate inhibition effect of CMCS could be improved by the introduction of hydroxypropyl-3-trimethylamine and N-2-hydroxypropyl-3-isooctyl ether groups based on the enhancement of the molecular hydrophobicity. At the same time, the introduction of the trimethyl quaternary ammonium group increased the ion content in the aqueous solution, which further inhibited the nucleation and growth of methane hydrates. This work is supposed to serve as an inspiration for the further research and development of green kinetic hydrate inhibitors with high-efficiency

Composition of <i style="mso-bidi-font-style: normal">n</i>-dedocyl polyglucoside based middle phase microemulsions in surfactant-enhanced aquifer remediation

873-878The composition and solubilization power of the middle phase microemulsion formed by n-dodecyl polyglucoside (APG)/ n-butanol/water/non-aqueous phase liquids (NAPLs) quaternary system have been studied. The hydrophile-lipophile balanced (HLB) plane equation for the quaternary system has been deduced. Some physicochemical parameter, such as the mass fraction of <i style="mso-bidi-font-style: normal">n-butanol in the HLB interfacial layer, the coordinates of the start and end points of the middle phase microemulsion, the mass fractions of APG and n-butanol in the total system, and the solubilities of APG and n-butanol in oil phase are calculated. The washing liquids prepared according to the physicochemical parameters of the n-dodecyl polyglucoside based middle-phase microemulsion have been used to wash the NAPLs adsorbed on soil. The results indicate that the APG based middle phase microemulsion is suitable in surfactant-enhanced aquifer remediation

Observation and Analysis of Leather Structure Based on Nano-CT

Content: The composition, working principle and the image acquisition procedure of nano-CT were introduced. A dried piece of blue stock of chrome-tanned cattle hide was chosen for this work and a sequence of 2356 images was obtained. 3D visible digital models (5mm*3.5mm*3.5mm) of leather fiber bundle braided network (Figure 1) and the interspace between fiber bundles (Figure 2) were reconstructed. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image. Based on the 3D model, the diameter, volume, surface area and other parameters of the fiber bundles, the pore structure and inclusions were measured and calculated. Take-Away: 1. 3D visible digital model of leather fiber bundle braided network was reconstructed. 2. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image

Novel one-pot synthesis of symmetrically substituted ureas

<p>We demonstrated a novel, facile, high-yield, and efficient one-pot approach for the synthesis of symmetrically disubstituted ureas from isocyanates in the presence of trimethylsilanol. This novel protocol boasts the use of inexpensive reagents, operational simplicity, excellent yields of products, environmentally friendly conditions, and easy workup. To the best of our knowledge, this is the first example of the synthesis of symmetrically disubstituted ureas from isocyanates in the presence of trimethylsilanol in one pot.</p

Mechanically Robust Hybrid POSS Thermoplastic Polyurethanes with Enhanced Surface Hydrophobicity

A series of hybrid thermoplastic polyurethanes (PUs) were synthesized from bi-functional polyhedral oligomeric silsesquioxane (B-POSS) and polycaprolactone (PCL) using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent for the first time. The newly synthesized hybrid materials were fully characterized in terms of structure, morphology, thermal and mechanical performance, as well as their toughening effect toward polyesters. Thermal gravimeter analysis (TGA) and differential scanning calorimetry (DSC) showed enhanced thermal stability by 76 &#176;C higher in decomposition temperature (Td) of the POSS PUs, and 22 &#176;C higher glass transition temperature (Tg) when compared with control PU without POSS. Static contact angle results showed a significant increment of 49.8&#176; and 53.4&#176; for the respective surface hydrophobicity and lipophilicity measurements. More importantly, both storage modulus (G&#8217;) and loss modulus (G&#8217;&#8217;) are improved in the hybrid POSS PUs and these parameters can be further adjusted by varying POSS content in the copolymer. As a biodegradable hybrid filler, the as-synthesized POSS PUs also demonstrated a remarkable effect in toughening commercial polyesters, indicating a simple yet useful strategy in developing high-performance polyester for advanced biomedical applications

Observation and Analysis of Leather Structure Based on Nano-CT

Content: The composition, working principle and the image acquisition procedure of nano-CT were introduced. A dried piece of blue stock of chrome-tanned cattle hide was chosen for this work and a sequence of 2356 images was obtained. 3D visible digital models (5mm*3.5mm*3.5mm) of leather fiber bundle braided network (Figure 1) and the interspace between fiber bundles (Figure 2) were reconstructed. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image. Based on the 3D model, the diameter, volume, surface area and other parameters of the fiber bundles, the pore structure and inclusions were measured and calculated. Take-Away: 1. 3D visible digital model of leather fiber bundle braided network was reconstructed. 2. The inner structure and composition of leather were shown accurately and intuitively in the form of 2D sectional images and 3D image