Silane coatings

Gottenbosa B, Henny C, van der Meia, Klatterb F, Nieuwenhuisb P, and Busscher HJ. In vitro and in vivo antimicrobial activity of covalently coupled quaternary ammonium silane coatings on silicone rubber. Biomaterials, 2002, 23, 1417-1423. 

Fig. 2.3.11 Left the ingress of a hydrophobic silane coating into building sandstone. Right subsequent water ingress and pumping through a treated surface.

When using poly-L-lysine or Silane-coated slides in enzyme digestion protocols, the method of their preparation determines the success of section adherence. The slides must be clean, and must be heated prior to deparaffinization. Experimentation can determine the slide coating that provides clean backgrounds with the technique of choice. 

Table III. Studies with Silane Coated Soda Lime Glass Beads...

Therefore, once the silane coated glass fibers are in contact with uncured resins, the R-groups on the fiber surface react with the functional groups present in the polymer resin, such as methacrylate, amine, epoxy and styrene groups, forming a stable covalent bond with the polymer (Fig. 5.3(d)). It is essential that the R-group... 

Wang, D., Jones F.R. and Denison, P. (1992c). A TOF SIMS study of the incorporation of aluminum into the silane coating on E-glass fibers. Catalysis Today 12, 375 383. 

Baseline Process. DuPont PI2545, PI2555 and Hitachi PIQ as received from the manufacturer, were spun in a class 100 clean room environment at appropriate spin speeds to achieve 0.5 - 6 y film thickness. The silicon wafer substrates were pre-spun (5K rpm, 30") with 0.05% DuPont VM651 (y-amino propyltriethoxy silane) adhesion promoter in 95/5 (v/v) methanol/HzO. The polyimide film cast on the silane-coated silicon wafer was pre-baked... 

When a silane coated wafer was baked at 400°C and examined by ESCA for surface elements it showed almost a total loss of carbon and amine nitrogen. We view this, therefore, as evidence that organic silane will not survive the bake and Si02 will remain. Results are presented in Table VI. 

TABLE VI - ESCA RESULTS OF SILANE COATING ON WAFER ELEMENTS... 

Many surface modifications are used with aluminium hydroxide, which responds to both silane and fatty acid treatments. Special proprietary silane coatings seem to be preferred for polypropylene applications [99]. Despite the production being water based, the preference seems to be for dry coating procedures. 

Silanes. Silanes and silane derivatives dominate the small market for inorganic binders. These materials are used both m combination with organic binders and by themselves. As co-binders, they increase the chemical and moisture resistance of a film, When used by themselves, they form brittle, very chemical-resistant films. Silane coatings are usually more expensive than their organic counterparts and must be kepi dry before application,... 

The heat of fusion of the composites with silane-coated glass beads was measured with a differential setinning calorimeter (Mettler TA4000) at a heating rate of 5 C/min. 

The uniformity of silane coatings was examined by scanning electron microscopy (SEM). SEM examination of the coated silanes showed a thin uniform coating to be present when a 0.5% silane aqueous solution was used. At higher silane concentrations, the coating was formed in lumps, which could clearly form a weak interphase when the fiber is embedded in the epoxy matrix. These observations are illustrated in Fig. 2. The formation of lumps of APS from a 5%... 

The acoustic energies of the pulses are shown in Fig. 11 and indicate the stress levels at which fracture has occurred in fibers of the same diameter. It is interesting to note here that fibers treated by the polymeric silane produce failure pulses at a higher energy than the untreated fibers. The protective effect of the polymeric silane coating in healing some surface flaws can be deduced from this observation. This effect is not significant when the monomeric silane is used. 

Sections (7 xm thick) of freshly frozen tissues are mounted on silane-coated slides and fixed with 4% buffered formaldehyde (pH 7.0) for 20 sec (Richter et al., 1999). The sections are rinsed in TBS (pH 7.4) for 15 sec, followed by incubation with EPOS antibody for 3 min at 37°C in an incubation chamber. They are rinsed twice for 15 sec each in TBS, and then developed with peroxidase-DAB detection kit (Dako) in a microwave oven (500 W) for 1 min during microwaving, the slides are cooled by a cold water bath (Werner et al., 1991). After being rinsed in tap water, the sections are counterstained with hematoxylin for lOsec. They are rinsed in tap water and cover-slipped. 

Tissue specimens are snap-frozen in liquid nitrogen for 30 sec immediately after removal and then transferred to a cryostat (Kammerer et al., 2001). Serial frozen sections of 5 pan thickness are cut and placed on silane-coated slides. They are air-dried for 30 sec, fixed in acetone for 1 min at room temperature (22°C), and air-dried at 22°C (Fig. 6.11). The sections are incubated with primary antibody in the antibody diluent (Dako) for 3 min by placing the slide horizontally on a hot plate at 37°C. (All incubation steps are carried out by placing the slide horizontally on the hot plate at 37°C.) Following a brief rinse in TBS, the sections are incubated with the goat-anti-mouse EnVision-HRP-enzyme conjugate for 3min at 37°C. 

Surgical breast biopsy specimens are first fixed with neutral buffered formalin (4%) for 4-6 hr, followed by zinc-formalin for 2 hr. Paraffin sections (5 xm thick) are placed on silane-coated slides, dried on a slide warmer (60°C) for 1 hr and then in an oven (60°C) for an additional 1 hr. Deparaffinized sections are digested with 0.1% trypsin in PBS at 37°C for 15 min. The sections are placed in 10 mM citrate buffer (pH 6.0) and transferred into a water bath (80° or 90°C) for 2 hr. After a 20-min cooling period, the sections are rinsed... 

Sections of formalin-fixed and paraffin-embedded tissues are placed onto silane-coated slides, deparaffinized, and rehydrated. They are placed in 0.1 M EDTA (pH 8.0) and exposed to steam heat for 30 min. The slides are cooled for 5 min, rinsed in tap water, loaded onto the ES Autostainer, and treated with Protease 2 (Ventana) for 8 min. Incubation is carried out in the primary 34 3E12 antikeratin (diluted 1 10 in PBS) for 32 min and in biotinylated secondary antibodies followed by streptavidin for 8 min each. The staining is visualized on the instrument using 3-amino-9-ethylcarbazole. Between each step, the slides are rinsed in Tris-buffered saline. The results of this protocol are shown in Figure 8.8. 

Sections (4 xm thick) of formalin-fixed and paraffin-embedded ovarian tissue are mounted on silane-coated slides and air-dried for 24hr at 3°C (Davidson et al., 2000). They are deparaffinized, rehydrated, placed in 0.01 M sodium citrate buffer (pH 6.0), and heated twice for 5 min each in a microwave oven. 2H5 antibody (PharMingen, Becton Dickinson, San Jose, CA) is used at a concentration of 2 p,g/ml to detect sialyl Lex antigen. Staining is performed with labeled avidin-biotin. Negative controls consist of the exclusion of the primary antibody, while positive controls consist of carcinomas that have been shown to be immunoreactive for the antigen in earlier studies. 

The following procedure is more suitable for routine application than other methods as many as 200 specimens can be processed at a time with this procedure. Sections (2 pm thick) of formalin-fixed and paraffin-embedded tissues are mounted on silane-coated slides. They are deparaffmized with xylene and rehydrated in a series of descending concentrations of ethanol. The sections are immersed in 0.01 M sodium citrate buffer (pH 6.0) in plastic Coplin jars and heated in an autoclave at 120°C for 20min. After the sections have cooled down to room temperature for 20 min, they are incubated in the freshly prepared following silver staining solution for 25 min at room temperature. 

Covalent bond formation is not an immediate process. Silane coating layers consist of physisorbed as well as chemisorbed molecules. Physisorbed molecules go into condensation only slowly and chemical stabilization of the coating layer requires a post-reaction curing step. In this step the modified substrate is thermally treated at temperatures generally in the 353 - 473 K range. 

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