Characteristics and Rheological Properties of Polysaccharide Nanoparticles from Edible Mushrooms (Flammulina velutipes)

Nanotechnology has become relevant in the food‐related industries, and edible mushrooms can be a potential raw material for providing satisfied edible nanomaterial. In this study, by following 3 different pretreatments (hot water or cold alkali or hot alkali) insoluble polysaccharide nanoparticles were prepared from Flammulina velutipes by wet milling and high pressure homogenization and their properties were investigated. The resultant nanoparticles were characterized by SEM, GC‐MS (for its main compositions), FTIR, XRD, and TG. The 1 wt% nanoparticle dispersions presented non‐Newtonian, shear‐thinning fluids with the viscosity in an increasing order for the hot water < cold alkali < hot alkali. Moreover, the dynamical rheological results showed differences of storage (G′) and loss (G″) moduli of these particle dispersions. It was concluded that the Flammulina velutipes‐derived polysaccharides nanoparticles have great potential applications in the food industry, for example, as emulsifiers, reinforcement agents, and bioactive carriers.     

Comparison of Dye Behavior from Aspen HYP: Dyes Added in the HYP Manufacturing Process Versus Dyes Added at the Papermaking Wet End

Abstract

The yellowish color of High Yield Pulp (HYP) gives some psychological obstacles and limits its application in some paper grades. Dyes are widely used in the papermaking process to shade the yellowish color of the paper products. We proposed to add dyes into the HYP manufacturing process to minimize the yellowish hue. In this work, we substituted the dye-added HYP (dyes added in the HYP manufacturing process) for hardwood kraft pulp in the production of fine paper grades, and compared the results from those by adding dyes into the papermaking wet end. A higher dye effectiveness was obtained when we used the dye-added HYP. Also, the dye-added HYP gave more effective performance of Precipitated Calcium Carbonate (PCC) fillers and Optical Brightening Agents (OBA) in terms of CIE whiteness and b*. In addition, the dye-added HYP showed less negative effect on brightness and better compatibility with other dyes. The underlying mechanism for the above experimental observation was proposed.     

高得率浆中DCS的性质及其对填料留着的影响

研究了不同白度高得率浆中溶解和胶体物质（DCS）的性质及其对填料留着的影响，并通过使用阴离子垃圾捕集剂来消除DCS的负面影响。结果表明，高得率浆的白度越高，浆料中所含的DCS越多；在多组分助留系统中采用阴离子垃圾捕集剂，特别是高分子质量的聚乙烯亚胺，能够有效消除DCS的不利影响。     

Removal of residual lignin of ethanol‐based organosolv pulp by an alkali extraction process

Organosolv pulps usually have high kappa number. This research investigated an alkaline extraction method prior to bleaching for reducing the kappa number of organosolv pulp. Ethanol wheat straw pulp with a kappa number of 58.2 was extracted with 1% NaOH solution. The results show that the ethanol pulp has a large amount of lignin particles on the fiber surface. After 1 min alkali extraction, the kappa number of the ethanol pulp is reduced by 60%, to 22.2, and both the number and the size of the lignin particles on the fiber surface are significantly reduced. In comparison with a further ethanol washing/extraction, the alkali extraction is much more effective in terms of lignin removal. X‐ray photoelectron spectroscopy results show that a thin layer of lignin remained on the fiber surface after alkli extraction, but this did not reduce the internal bond strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Improvement of Furfural Production from Concentrated PreHydrolysis Liquor (PHL) of a Kraft-Based Hardwood Dissolving Pulp Production Process

Hemicelluloses present in the prehydrolysis liquor (PHL) of the hardwood kraft-based dissolving pulp production process can be utilized in the production of furfural, which is an important renewable, non-petroleum-based platform chemical. A lower furfural yield was observed from the concentrated sugars in PHL in acetic-acid-catalyzed systems. The reaction rate of sugar consumption and furfural destruction in PHL was higher than those of model xylan and xylose systems, which may be due to the side-reactions of lignin with sugars and carbonization of oligomeric sugars. In order to minimize these side-reactions, a steam-stripping method of generated furfural was adopted. The results showed that the method was effective in increasing the furfural yield (41.5%) from the concentrated PHL.     

Steady state modelling and simulation of an indirect rotary dryer

A steady state model for a fish meal indirect pilot plant rotary dryer with steam tubes is developed. The model is based on mass and energy balances and heat transfer constitutive equations. Simulated and experimental results are presented. The moisture condition of fish meal predicted by the model agrees satisfactorily with experimental values obtained in the pilot plant dryer within the range of operating conditions explored.     

Poly lactic acid nanocomposites containing modified nanoclay with synergistic barrier to water vapor for coated paper

The binary nanocomposites of poly lactic acid (PLA) with the montmorillonite modified with trisilanol polyhedral oligomeric silsesquioxanes (Trisilanolisooctyl POSS^®) were prepared via a solution‐blending process and coated on paper by bar coating and compress hot melt coating methods. The resulting components were characterized with Fourier transform infrared spectroscopy, and X‐ray diffraction (XRD) techniques. Moreover, the water vapor transmission rates (WVTR) for the coated writing paper were determined using an IGA‐003. The results indicated that the modified clay PLA nanocomposites enhanced the water vapor barrier properties of coated paper significantly. The permeability of PLA nanocomposites to water vapor decreased by 74% [26.0 g/(m² day)], respectively, as compared to those of the paper coated with pure PLA. The dispersion and phase behavior of the modified montmorillonite in PLA matrix was revealed by Transmission electron microscope. The intercalation of montmorillonite with PLA was further demonstrated using XRD. WVTR results indicated that the compress hot melt coating of the nanocomposites is an effective method to improve the water vapor resistance of coated paper. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40952.     

纤维素负载金属基催化体系在有机反应中的研究进展EI北大核心CSCD

金属基催化剂现已成为催化领域的主流催化剂,但其存在难以分离循环使用、催化剂遗留、成本较高、催化剂与底物不稳定性等问题,采用高分子载体进行负载是解决以上问题的一种有效方法。纤维素是地球最丰富的绿色高分子,作为催化剂载体具有来源广泛、可生物降解、无毒、良好的生物相容性的优异特点,且分子结构上具有大量的羟基易改性、可通过多种方式负载金属催化剂。因此,本文综述了纤维素作为载体,负载零价金属纳米粒子、非零价金属基催化剂的进展,以及对负载后的催化体系在氧化还原反应、Heck反应、Suzuki反应等反应中的催化活性进行概述;并通过对比该体系中载体-金属等之间的作用机理,阐述了不同负载方式之间的协同作用,以及催化活性的差异性。