Substrate pretreatment

Adhesion of copper films to PMDA/ODA polyimide was determined by peel tests conducted on samples that were prepared by vapor-depositing a thin layer of copper onto the polyimide and then building the thickness of the metal layer to about 18 p,m by electrodeposition of copper. Results of the adhesion measurements correlated well with substrate pretreatment. When the substrate... 

A Box-Behnken design was employed to investigate statistically the main and interactive effects of four process variables (reaction time, enzyme to substrate ratio, surfactant addition, and substrate pretreatment) on enzymatic conversion of waste office paper to sugars. A response surface model relating sugar yield to the four variables was developed on the basis of the experimental results. The model could be successfully used to identify the most efficient combination of the four variables for maximizing the extent of sugar production. 

Recently Butler et al. [4] reported the deposition of nanocrystalline diamond films with the conventional deposition conditions for micrometer-size polycrystalline diamond films. The substrate pretreatment by the deposition of a thin H-terminated a-C film, followed by the seeding of nanodiamond powder, increased the nucleation densities to more than 10 /cm on a Si substrate. The resultant films were grown to thicknesses ranging from 100 nm to 5 fim, and the thermal conductivity ranged from 2.5 to 12 W/cm K. 

Fig. 3. Effect of substrate pretreatment on the durability of titanium/epoxy joints 241...

Figure 1A shows the effect of HLB value of NP series surfactant on digestibility at a surfactant loading of 0.5 wt%. The HLB values of NP-5, -10, and -20 are 10.0, 13.3, and 16.0, respectively (Table 1). Here, control sample means a substrate pretreated without surfactant. After pretreatment, a dark-colored band consisting of ink components was observed in the upper portion of the bottle in the control sample, whereas no dark-colored band was observed in the NP-added samples (not shown). It was... 

Commercially available M, iuteus cultures often show distinct differences in sensitivity due to specific conditions of growth, harvesting, and processing. Appropriate substrate pretreatment for obtaining a reproducible and homogeneous suspension is also of utmost importance. 

Conventional coating approaches to TPO, which rely on the use of substrate pretreatments such as flaming, corona discharge, plasma or chemical pre-treatment, have led to a substantial oxidation of the surface, which enhances adhesion. These pretreatments, however, have a limited service life before the surface reverts to its unoxidized, apolar condition. 

Recently a new technique has been reported under the name of the QQC process. It utilizes a combination of lasers and does not require vacuum, ambient or substrate pretreatments. The main source of carbon is CO and the films have been deposited on different metal and ceramic substrates. 

Because of the long incubation period involved in the formation of a stable surface before onset of nucleation, the nucleation density observed on most substrates, for practically feasible deposition periods, is too httle. Different substrate pretreatments have been attempted to improve the nucleation density. 

Substrate Pretreatment Tape test rating El E2 NMP time (min) ... 

As a standard procedure of substrate pretreatment for diamond deposition, (i) scratching the substrate surface with diamond powder or paste, or (ii) ultrasonic treatment of the substrate in diamond powder suspended in alcohol are widely used. By contrast, for diamond growth on cBN(Ill), no such pretreatment is necessary, partly because of the close match of lattice constants. 

The atomic images at diamond/substrate interfaces is shown later. The presence or absence and the structures of the interface layers depend on the method of substrate pretreatment, the diamond CVD method and the growth conditions used. The investigation of the atomic interface structures will give us useful insight into the nucleation and heteroepitaxial growth of diamond. 

For a cellulosic material such as wood chips or crop waste, cellulase enzymes cannot penetrate the structure and make glucose. A pretreatment is required to destroy the fiber structure and allow cellulase access to the substrate. Pretreatment is typically carried out at 180-250 °C for a few seconds to a few minutes in 0.5% to 2% sulfuric acid. The resulting material is of a muddy texture. An aqueous slurry of pretreated cellulose is made at 5% to 15% sohds. Cellulase enzymes are added at a concentration of 5 to 25 filter paper units per gram of cellulose. The slurry is stirred, and the enzymatic hydrolysis is carried out for 4 to 7 days. At this point, most of the cellulose is converted to glucose, and the unhydrolyzed residue consists primarily of lignin. 

Variations in morphology and adsorption properties of PTFE coatings along with the effect the substrate pretreatment have been studied at the initial stages of coating formation. PTFE coatings have been deposited from the active gas phase obtained by the electron-beam dispersion of the original powder of polymer in vacuum [4],... 

Z. P. Lu, J. Heberlein, and . Pfender, Process study of thermal plasma chemical vapor deposition of diamond, n. Pressure dependence and effect of substrate pretreatment. Plasma Chem. Plasma Proc., 12(l) 55-69 (1992)... 

H. Maeda, S. Masuda, K. Kusakabe, and S. Morooka, Nucleation and growth of diamond in a microwave plasma on substrate pretreated with non-oxide ceramic particles, J. CrysL Growth, 121(3) 507-515 (1992)... 

Table 2 Pretreated com stover substrates pretreatment information and glucan, xylan and lignin content as a fraction of the pretreated material.

Meimingen et al. (1994) carried out a number of time-resolved species density measurements as part of their substrate pretreatment studies. They observed that when 3% C2H2 diluted in H2 was used as the feed gas, the CHj density increased quickly to about 2xl0 cm , followed by a rapid decline to about 2xl0 cm during the pretreatment. When the C2H2 concentration was reduced to 0.36%, the CH3 density abruptly increased to about... 

Flaking reduces particle size, and hence, diffusion distance of the solute through the meal substrate. More importantly, as thickness decreases proportionately more cell walls are ruptured eliminating diffusion barriers. If cell walls encapsulate the valued components in a botanical substrate, pretreatment to rupture the cell walls significantly improves both yield and rate of extraction. 

Yokota, S., Kitaoka, T., Wariishi, H. Surface morphology of cellulose films prepared by spin coating on silicon oxide substrates pretreated with cationic polyelectiolyte. App. Surf. Sci. 253, 4208 214 (2008)... 

A number of important factors must be considered when studying TOF-SIMS of polymers. Included are the nature of the substrate, substrate coverage, substrate pretreatment, the primary ion, polymer molecular weight, and the solvent used in sample preparation. 

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