A Novel Two-Step Silica-Coating Process for Engineering Magnetic Nanocomposites

1998 ◽  
Vol 10 (12) ◽  
pp. 3936-3940 ◽  
Author(s):  
Qingxia Liu ◽  
Zhenghe Xu ◽  
J. A. Finch ◽  
R. Egerton
Keyword(s):  
Silica Coating ◽  
Magnetic Nanocomposites ◽  
Coating Process

Coated Magnetic Nanoparticles for Acidic Nuclear Waste Separation

2010 ◽  
Vol 1265 ◽  
Author(s):  
Maninder Kaur ◽  
Hongmei Han ◽  
Andrew Johnson ◽  
Jesof Kaczor ◽  
Andrzej Paszczynski ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Solvent Extraction ◽  
Ion Exchange ◽  
Nuclear Waste ◽  
Cost Effective ◽  
Silica Coating ◽  
Coating Process ◽  
Acidic Conditions ◽  
Allylamine Hydrochloride ◽  
Waste Separation

AbstractActinide specific chelator (che) conjugated with magnetic nanoparticles (MNPs) have been developed to separate nuclear waste in acidic conditions. Compared to the traditional nuclear waste treatments, such as solvent extraction and ion exchange, this method is a simple, compact and cost-effective process that generates minimum secondary waste. In this paper, we focus on the coating process of MNPs to achieve a combination of good acidic resistance, high chelator loading density and efficient magnetic separation. An optimized silica coating process before conjugates chelator directly onto MNPs significantly improves the acidic resistance of the MNP-che complex. Chelator loading density is significantly increased by attaching a linear polyamine polymer poly(allylamine hydrochloride) (PAH) to the surface of the MNPs using chemical and physical approaches.

Preparation of Acid-Resistant Ultramarine Pigment by Dense Silica Coating Process

2011 ◽  
Vol 233-235 ◽  
pp. 246-249 ◽  
Author(s):  
Si Fang Li ◽  
Miao Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Acid Resistance ◽  
Silica Coating ◽  
Sem Analysis ◽  
Solid Content ◽  
Operating Conditions ◽  
Blue Pigment ◽  
Orthogonal Experimental Design ◽  
Coating Process ◽  
Ultramarine Blue

Acid-resistant ultramarine blue pigment with a silica shell was prepared by dense silica coating process. From X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) analysis, it was confirmed that silica in the coating is attached on the ultramarine particles surface by characterizing the composition of elements and the microstructure on the surface of the silica coated particles. Orthogonal experimental design was applied to optimize the operating conditions of the coating process. The best acid resistance for the coated ultramarine blue reached the ninth grade under the following conditions: silica adding rate of 5 g/h, solid content of 6 g/l in the slurry and coating time of 2.5 h.

scholarly journals Electrophoretic silica-coating process on a nano-structured copper electrode

2008 ◽  
pp. 5004 ◽  
Author(s):  
Laurent Bazin ◽  
Marie Gressier ◽  
Pierre-Louis Taberna ◽  
Marie-Joëlle Menu ◽  
Patrice Simon
Keyword(s):  
Silica Coating ◽  
Copper Electrode ◽  
Coating Process

Amorphous silica coating on α-alumina particles

1995 ◽  
Vol 53 ◽  
pp. 210-211
Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay
Keyword(s):  
Amorphous Silica ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Silica Coating ◽  
Full Density ◽  
Optimal Conditions ◽  
Fine Grained ◽  
Alumina Particles ◽  
Complete Mullitization ◽  
Powder Compacts

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.

Economics of coated paper production made from deinked pulp

TAPPI Journal ◽  
2013 ◽  
Vol 12 (4) ◽  
pp. 19-27
Author(s):  
PATRICK HUBER ◽  
LAURENT LYANNAZ ◽  
BRUNO CARRÉ
Keyword(s):  
Mechanical Properties ◽  
Optimization Methods ◽  
Coating Process ◽  
Coated Paper ◽  
Paper Production ◽  
Base Paper

The fraction of deinked pulp for coated paper production is continually increasing, with some mills using 100% deinked pulp for the base paper. The brightness of the coated paper made from deinked pulp may be reached through a combination of more or less extensive deinking, compensated by appropriate coating, to optimize costs overall. The authors proposed general optimization methods combined with Kubelka-Munk multilayer calculations to find the most economical combination of deinking and coating process that would produce a coated paper made from DIP, at a given target brightness, while maintaining mechanical properties.

Depletion of coating color components in the blade coating process circulation

TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 17-23 ◽  
Author(s):  
ANNE RUTANEN ◽  
MARTTI TOIVAKKA
Keyword(s):  
Fine Particles ◽  
Particle Density ◽  
Stable Process ◽  
Size Fraction ◽  
Color Stability ◽  
Strong Interactions ◽  
Coating Process ◽  
Size Segregation ◽  
Coating Color ◽  
Average Size

Coating color stability, as defined by changes in its solid particle fraction, is important for runnability, quality, and costs of a paper coating operation. This study sought to determine whether the size or density of particles is important in size segregation in a pigment coating process. We used a laboratory coater to study changes in coating color composition during coating operations. The results suggest that size segregation occurs for high and low density particles. Regardless of the particle density, the fine particle size fraction (<0.2 μm) was the most prone for depletion, causing an increase in the average size of the particles. Strong interactions between the fine particles and other components also were associated with a low depletion tendency of fine particles. A stable process and improved efficiency of fine particles and binders can be achieved by controlling the depletion of fine particles.

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