Pretreatment glass

Chirasil-Val, which is commercially available in both enantiomeric forms143, is stable up to 240 C when coated on carefully pretreated glass or fused silica capillary columns. The best performance is obtained when the chiral side chains in Chirasil-Val are separated by an average of five dimethylsiloxane units144. Using a Chirasil-Val column, the simultaneous enantiomer separation of all proteinogenic amino acids is possible (Figure 11). 

Measurement of dissolved mercury compounds requires removal of particulate materials from the sample by either filtration or centrifugation. Various types of filters can be employed 0.45 pm membrane filters (precipitation, seawater), disposable polystyrene units (Nalgene) with nitrocellulose membrane filters, and pretreated glass fiber filters. 

The pretreated glass substrate was dipped into the coating solution for 30 s and subsequently withdrawn vertically at a constant speed of 2.5 mm/s. The coatings obtained were kept at room temperature for 30 min and then dried in an oven at 60°Cfor24h. 

Un-OH can also be copolymetized with propene on a MAO-pretreated glass surface by Et(Ind)2ZrCl2. Parts of the resulting copolymer are chemically bonded to the surface, as shown by extraction experiments, scanning electron microscopy (SEM) microscopy as well as Fourier transformation infrared spectroscopy (FUR) analysis. Similar results were reported for the copolymerization of ethene with Un-OH by the same catalyst system on the organically modified silicate montmorillonite (OMMT) resulting in PE-Un-OH/OMMT nanocomposites which consist of well-exfoliated OMMT dispersions and controlled degrees of PE functionalization. ... 

In recent years, prices for natural fibers were not stable, especially for flax fibers. Flax fibers, showing the highest values for strength (Table 2), are about 30% more expensive than glass fibers. Additionally, is price depends on the fiber preparation. Usually, glass fibers are delivered pretreated, i.e., treated with different sizes... 

The mechanical properties of composites are mainly influenced by the adhesion between matrix and fibers of the composite. As it is known from glass fibers, the adhesion properties could be changed by pretreatments of fibers. So special process, chemical and physical modification methods were developed. Moisture repel-lency, resistance to environmental effects, and, not at least, the mechanical properties are improved by these treatments. Various applications for natural fibers as reinforcement in plastics are encouraged. 

The gas feed and mixing system consists mainly of glass flowmeters or electronic mass flowmeters connected to gas bottles. For reactants that are in liquid state at room conditions (e. g. methanol) a saturator is normally used through which helium is sparged and then mixed with the other reactants. In this case all lines connected to the reactor are heated (e.g. at 150°C) to avoid condensation in the lines. In certain cases the gases from the bottles should be pretreated in order to avoid contamination of the catalyst. For example, a... 

Wilson, M. A. Combe, E. C. (1991). Effects of glass composition and pretreatment on the reactivity of a novel glass polyalkenoate (glass ionomer) dental cement. Clinical Materials, 7, 15-21. 

The nylon or glass substrate on which the probe solution is deposited must be pretreated with coupling agents such as lysine or acrylamide functional groups. Coupling agents bind the probe cDNA to the substrate. After hybridization, the array is washed in heated isopropanol and water to remove any unhybridized sample DNA. It is essential... 

Helmuth DW, Ghiasuddin SM, Soderlund DM (1983) Poly(ethylene glycol) pretreatment reduces pyrethroid adsorption to glass surfaces. J Agric Food Chem 31 1127-1129... 

---