Single cantilever mode

DMT A measurements were made with a Polymer Labs instrument. Samples were clamped in the single cantilever mode in a frame of 22 mm using 6 mm clamps with 0.5 mm faces. The sample length between the clamps was 8 mm. Measurements were performed at a frequency of 1 Hz, a strain amplitude of 0.063 mm and a heating rate of 5 K.min . Clamping was checked by monitoring the strain amplitude on an oscilloscope. The measurements were carried out in air. Values of the temperature of maximum mechanical loss, T (tan 5max). were reproducible to 2 K. 

All studies were performed under nitrogen (< 2ppm oxygen) using the single cantilever mode of the Polymer Labs DMTA at small deformation, 1 hz, and a heating rate of 5 or 0.5 °C/min. 

Dynamic mechanical thermal analyses were carried out using a Polymer Laboratories DMTA equipped with a high temperature (500°C) head operating at a frequency of 1 Hz and a constant strain, x 1, in the single cantilever mode. The thickness of the PES/PI2080 films was in the range of 0.1-0.2 mm and that of the PES/PI XU 218 films was 0.2-0.3 mm. 

Figure 13 Forced vibration bending in the (a) dual- and (b) single-cantilever modes...

The glass transition temperature and the modulus of the cured matrix were measmed by dynamic mechanical analysis (DMA) in the single cantilever mode, at a frequency of IHz. DMA runs were reeorded with a DMA 2980 Dynamic Mechanical Analyzer from TA instruments. The glass transition temperature (Tg) was measured at the maximum of the Tan delta (5) curve dedueed from DMA experiments. Storage modulus of the matrix was determined at 40°C. 

Dynamic mechanical properties were evaluated using a TA Instrument Dynamic Mechanical Analyzer (DMA) that was assembled into the single-cantilever mode. Specimens were cut to a length of 30 mm while the span length was set at 17 mm. Temperature scans were conducted at a range of 30 to 180 C for all specimens. 

For the measurements, the single cantilever flexure mode was chosen. For this, rectangular polymer samples of 32 mm x 6 mm x 2 mm had to be produced. This was done by injection molding of the original polymers. Fig. 8 shows the setup of a DMA-experiment in the single cantilever configuration. 

Figure 1 Common mechanical deformation modes compression, tension, shear, torsion, bending single cantilever, dual cantilever, three point bending)...

Geometry options single-cantilever bending 1.0-17.5 mm dual-cantilever bending 2.0-35.0mm three-point bending 20.0-45.0mm Tension <10 mm compression unlimited, <10 mm Shear 10-mm-diameter plate TMA-mode measurement range 1000 pm... 

Note that for these definitions the sample length, /, is always taken as the distance between the fixed clamp and the driveshaft clamp. Therefore samples in single and dual cantilever mode will both have the same length for a given clamp spacing. Similarly, the sample length... 

Mechanical testing was performed on epoxy resin toughened by incorporation of up to 17 vol% of PEI.1 The dynamic mechanical tests were carried out in DMTA at 10 Hz, in a single cantilever bending mode at r = -80 to 300°C. The flexural properties at 23°C were carried... 

Figure 3. AFM images of the silver nanoparticles on the Xi02(l 00) single crystal at the deposition times of (a) 15s and (b) 180 s. The images were recorded in a tapping mode with driving frequency of 110-150 kHz at a scan rate of 1 Hz by using a silicon cantilever with a normal spring constant of 15Nm (SI-DF20, Seiko instruments).

For CM-AFM, soft cantilevers with spring constants between 0.02 N/m and 0.3 N/m are frequently used in liquids, while for intermittent contact modes various possibilities exist. Many researchers have successfully employed contact mode cantilevers (triangular and preferably single beam) with a spring constant between... 

For TM-AFM operation under liquid, the system is set up similar to the contact mode in liquid. By contrast, the cantilevers used are typically much softer than for operation in air. Often conventional contact mode levers (spring constant of 0. 3-few N/m) are used single beam cantilevers work in some cases better than triangular levers. The tuning of the lever is performed after the crude approach has... 

Static Mode in Liquids In liquids, the capillary force is not present allowing a more straightforward interpretation of the results. Furthermore, the contact area is as small as a single-atom contact. Special cantilevers have to be used for the operation in liquid. When reused, those cantilevers must be carefully cleaned and are best kept wet until employed again. 

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