Wetting paper

Another significant end-use for polyamines is in preparation of paper wet-strength resins. These are polyamide, modified formaldehyde, and polyamine resins used to improve the physical strength of tissue, toweling, and packaging paper products. The cationic formaldehyde resins include both urea—formaldehyde and melamine—formaldehyde types (248,249). Cationic functionaHty is imparted by incorporation of DETA, TETA, and/or TEPA in... 

Two thin layer chromatography (t.l.c.) tanks are used into the first tank is poured n-hexane to a depth of 10mm and into the second toluene similarly. The ends of the tanks are lined with filter paper wetted with the solvent in the tank. The tank covers are replaced and allowed to equilibrate for 30min. 

Anode Pt Ru=1 1 Unsuported, 5mg/cm Cathode 40 wt.% Pt/C, 1 mg/cm Membrane Nation 112 Backings Carbon Fil r Paper, Wet-proofed Cell active area 5cm ... 

Apply some drops of kerosene on the cooling block of the horizontal electrophoresis apparatus and apply the IPG strips with the acidic side to the anode. Make 1 cm broad strips from 2 mm thick filter paper. Wet the strips with deionized water (no ultra-pure water ) and place them on top of the IPG strips as well as at the anodic (acidic) and the cathodic (basic) ends of the strip(s). 

Reaction of Chlorine with Compounds. 1. Take a strip of filter paper, wet it with several drops of freshly distilled turpentine, and introduce it, using pincers, into a bottle with chlorine. What is observed Write the equation of the reaction. 

Put several iron II) sulphate crystals on the lid of a porcelain crucible, heat them, and then strongly roast them. Hold litmus paper wetted with water over the crystals. What happens Write the equation of the reaction. 

Transfer a small amount of the prepared substance from the boat into a beaker and pour a small amount of water over it. Test the evolving gas with moist litmus paper or a strip of filter paper wetted with a mercury(l) nitrate solution. Write the equations of the reactions. 

The dwarf mutant corn (d-1) plants were germinated in soil-vermiculite, transferred when they were nearly ready for bioassay treatment (14), and grown in a growth chamber at about 25° to 30° C. with continuous white fluorescent light of about 450 foot-candles. The roots of the com were supported on filter paper wetted with Hoagland s solution and affixed to slanting glass plates, sup-... 

A protein is spotted onto a piece of filter paper wetted with a pH buffer lower than the pi of the protein. This paper is placed in a DC electric field. The protein will migrate towards ... 

Fig. 19 Simulated copper corrosion in paper. Wetting (left) and fluorescence labeling (right) to visualize areas of pronounced oxidative damage...

Paper Treating. MF resins are used in some paper coatings and as paper wet-strength resins. Both of these applications appear to be declining because alternate compounds have been identified... 

Electrophoresis uses differences in isoelectric points to separate mixtures of amino acids (Figure 24-4). A streak of the amino acid mixture is placed in the center of a layer of acrylamide gel or a piece of filter paper wet with a buffer solution. Two electrodes are placed in contact with the edges of the gel or paper, and a potential of several thousand volts is applied across the electrodes. Positively charged (cationic) amino acids are attracted to the negative electrode (the cathode), and negatively charged (anionic) amino acids are attracted to the positive electrode (the anode). An amino acid at its isoelectric point has no net charge, so it does not move. 

Place the plate with the gel on a clean glass plate (bigger than the gel plate), and cover the gel with a layer of filter paper wetted with water (avoid air bubbles). 

After washing, cover the gel plate with a layer of filter paper wetted with water (to avoid air bubbles) and dry in hot air from a hair drier or in an oven. Drying is complete when the filter paper begins to lift from the plate. Drying the gel too fast or with too much heat will produce cracking or cause the filter paper to stick on the gel (s Note 6). 

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