Glass capillary tube

Streaming potential measurements are to be made using a glass capillary tube and a particular electrolyte solution, for example, O.OIM sodium acetate in water. Discuss whether the streaming potential should or should not vary appreciably with temperature. 

The capillary tube method initially involves packing a powdered sample into a glass capillary tube of uniform diameter and length, carefully sealed at one end so that it forms a rounded tube of uniform thickness. The tube is then attached to a standardized thermometer so that the end of the tube reaches the middle of the thermometer reservoir bulb. This assembly is then inserted into a vessel contg a suitable liq which is uniformly heated so that the temp rises at a rate of about 1° per minute. Ref 1 discusses in detail equipment design and thermometer calibration. It should be noted that this technique is the method most widely used by organic chemists... 

Irradiation Procedure. Reaction mixtures were prepared at room temperature by transferring desired quantities of reactants from their storage bulbs to the reaction vessel, a 500-cc. spherical borosilicate glass flask attached to the vacuum line by a section of glass capillary tubing and a 4-mm. bore threaded glass valve with a Teflon plug (Fischer and Porter 795-609). Prior to each experiment this vessel was baked under vacuum at 500°C. for 12 or more hours. 

Interfacial Tension (IFT) Measurements. All IFT measurements were done using a University of Texas Model 300 Spinning Drop Interfacial Tensiometer. The basic principle is to introduce a drop (about 2 p ) of an oil sample into a glass capillary tube (1.5 mm I.D., 78 mm long) filled with the aqueous medium. The tube is then spun about its main axis. The oil drop will elongate to a length determined by the IFT value of the system. Details of the theory and application can be found elsewhere (15.16). According to the equipment manufacturer, the formula used to calculate IFT value is ... 

Diagnosis Oa consumption Very simple and economical not quantitative Glass capillary tubing (ST)... 

In TLC, a 10- iL or larger syringe is often used to place sample spots on the thin layer before development. Alternately, a glass capillary tube or Pasteur pipette may be heated in a burner and pulled to obtain a fine capillary suitable for spotting (see Figure 13.3). 

Weigh liquids in a glass capillary tube 2 mm. in diameter and 7 to 8 cm. long cut with a sharp glass-knife from a drawn-out test tube. First close the tube (Fig. 35) in the middle by fusing the glass over a very small... 

It is common observation that a liquid takes the shape of a container that surrounds or contains it. However, it is also found that, in many cases, there are other subtle properties that arise at the interface of liquids. The most common behavior is bubble and foam formation. Another phenomena is that, when a glass capillary tube is dipped in water, the fluid rises to a given height. It is observed that the narrower the tube, the higher the water rises. The role of liquids and liquid surfaces is important in many everyday natural processes (e.g., oceans, lakes, rivers, raindrops, etc.). Therefore, in these systems, one will expect the surface forces to be important, considering that the oceans cover some 75% of the surface of the earth. Accordingly, there is a need to study surface tension and its effect on surface phenomena in these different systems. This means that the structures of molecules in the bulk phase need to be considered in comparison to those at the surface. 

We use 100 pi glass capillary tubes (VWR international 53432-921) pulled by a horizontal micropipette puller (Sutter Instrument Co. Model P-97) for suctioning of adipose tissue. Suction strength is controlled by tip size which is typically 10-20 pm. 

IFS66-FRA-106 FT-Raman spectrometer equipped with a liquid-Nj cooled Ge-diode detector. Samples were in small glass capillary tubes at 23°C. The spectra were calculated by averaging -200 scans followed by apodization and fast-Fourier-transformation to obtain a resolution of -2 cm and a precision better than 1 cm . The spectra were not corrected for (small) infensity changes in detector response versus wavelength. 

For the X-ray scattering observations the samples were powdered and placed in Lindemann glass capillary tubes. The capillaries were held for 8 weeks at 293 K in closed containers in contact either with hexane vapour or with aqueous salt solutions of different relative humidity. At the end of the preparation, the capillary tubes were flame-sealed. X-ray measurements were made at the BM2 bending magnet beam line at the ESRF, Grenoble, France. With incident energy 18 keV, the wave vector range explored was 6x 10 [Pg.44]

Liquids Supehheateu in Open, Glass Capillary Tubes at 1 Atm. (K2)... 

X-Ray Powder Patterns. Samples for x-ray pattern determinations were sealed in 0.2-mm. glass capillary tubes under an atmosphere of argon. The samples were then exposed to nickel-filtered, CuKa radiation in an 11.459-cm. Debye-Scherrer camera for 18 to 20 hours. 

Consider that a potential difference is applied across a glass capillary tube filled with an electrolytic solution (Fig. 6.134). What would one expect Of course, one would expect a current to flow through the capillary according to Ohm s law. In practice, however, a remarkable and unexpected phenomenon is observed. In addition to the current, the solution itself begins to flow—the phenomenon of electro-osmosis. Liquid flow is generally associated with the application of a pressure gradient, but in this case it appears that a potential difference is doing the job normally achieved by a pressure difference. 

The titration of 29 fmol (f = femto = 10 15) of HN03 in a 1.9-pL (p = pico = 10 12J water drop under a layer of hexane in a Petri dish was carried out with 2% precision, using KOH delivered by diffusion from the 1-pm-diameter tip of a glass capillary tube. The agar plug in the tip of the pipet regulates diffusion... 

This value is obtained in a Pyrex capillary tube the solid remains yellow until about 2540 when it suddenly decomposes to a red melt with vigorous evolution of gas. When a soft-glass capillary tube is used, the solid assumes a red color at about 180-200° and melts between 240° and 250°. 

Fig. 1.12. Assembly of a filter cannula or Green filter. (a) A piece of glass capillary tubing, which has been blown open and fire-polished to form a lip on one end, is attached to the cannula with epoxy cement, (b) Filter paper is folded over the glass capillary and secured with wire.

Calculate the rate of electro-osmotic flow of water at 25°C through a glass capillary tube 10 cm long and 1 mm diameter when the potential difference between the ends is 200 V. The zeta potential for the glass-water interface is -40 mV. 

---