Carboxymethyl cellulose-based water barrier coating regulated postharvest quality and ROS metabolism of pakchoi (Brassica chinensis L.)

The high temperature corrosion behavior of thermal barrier coating (TBC) systemconsisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%)bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coatwere characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt%Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC andinteraction times from 1 up to 8 h. The upper surface plan view of the coatings wereidentified for topography, roughness, chemical composition, phases and reaction productsusing scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-raydiffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed thephase transformation of nontransformable tetragonal (t') into monoclinic phase, presence ofYVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed theformation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2.The formation of these compounds were combined with formation of monoclinic phase (m)from transformation of nontransformable tetragonal phase (t').

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Contrasting underlying mechanisms of different barrier coating types

TAPPI Journal ◽

10.32964/tj17.01.31 ◽

2018 ◽

Vol 17 (01) ◽

pp. 31-37

Author(s):

Bryan McCulloch ◽

John Roper ◽

Kaitlin Rosen

Keyword(s):

Food Packaging ◽

Underlying Mechanism ◽

Consumer Products ◽

Mechanical Degradation ◽

Design Rules ◽

Barrier Coatings ◽

Barrier Materials ◽

Barrier Coating ◽

Coating Type ◽

Underlying Mechanisms

Barrier coatings are used in applications including food packaging, dry goods, and consumer products to prevent transport of different compounds either through or into paper and paperboard substrates. These coatings are useful in packaging to contain active ingredients, such as fragrances, or to protect contents from detrimental substances, such as oxygen, water, grease, or other chemicals of concern. They also are used to prevent visual changes or mechanical degradation that might occur if the paper becomes saturated. The performance and underlying mechanism depends on the barrier coating type and, in particular, on whether the barrier coating is designed to prevent diffusive or capillary transport. Estimates on the basis of fundamental transport phenomena and data from a broad screening of different barrier materials can be used to understand the limits of various approaches to construct barrier coatings. These estimates also can be used to create basic design rules for general classes of barrier coatings.

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Complex formation of modified chitosan and carboxymethyl cellulose and its effect on paper properties

TAPPI Journal ◽

10.32964/tj8.6.29 ◽

2009 ◽

Vol 8 (6) ◽

pp. 29-35 ◽

Cited By ~ 11

Author(s):

PEDRAM FATEHI ◽

LIYING QIAN ◽

RATTANA KITITERAKUN ◽

THIRASAK RIRKSOMBOON ◽

HUINING XIAO

Keyword(s):

Carboxymethyl Cellulose ◽

Polymer System ◽

Layer By Layer ◽

Paper Strength ◽

Anionic Polymer ◽

Paper Properties ◽

Modified Chitosan ◽

Layer By Layer Assembly ◽

Polyelectrolyte Titration ◽

Layer Assembly

The application of an oppositely charged dual polymer system is a promising approach to enhance paper strength. In this work, modified chitosan (MCN), a cationic polymer, and carboxymethyl cellulose (CMC), an anionic polymer, were used sequentially to improve paper strength. The adsorption of MCN on cellulose fibers was analyzed via polyelectrolyte titration. The formation of MCN/CMC complex in water and the deposition of this complex on silicon wafers were investigated by means of atomic force microscope and quasi-elastic light scattering techniques. The results showed that paper strength was enhanced slightly with a layer-by-layer assembly of the polymers. However, if the washing stage, which was required for layer-by-layer assembly, was eliminated, the MCN/CMC complex was deposited on fibers more efficiently, and the paper strength was improved more significantly. The significant improvement was attributed to the extra development of fiber bonding, confirmed further by scanning electron microscope observation of the bonding area of fibers treated with or without washing. However, the brightness of papers was somewhat decreased by the deposition of the complex on fibers. Higher paper strength also was achieved using rapid drying rather than air drying.

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