in this research, the effect of catalyst type on the cnts synthesis was investigated. the carbonnanotubes (cnts) were produced on stainless steel substrates and two of catalyst with differentcharacteristics by using thermal chemical vapor deposition (tcvd) method. the catalysts have theimportant role for the growth carbon nanotubes (cnts). acetylene gas (c2h2) diluted by nh3 wasused as the reac...

in recent years, it has become evident that it is necessary to systematically and accurately define particle characteristics in order to understand the potential toxicity of nanoparticles to biological systems. the properties that need to be emphasized are size, shape, dispersion, doping, aggregation, functionalization, physical and chemical properties, surface area, and surface chemistry. rout...

An analytical model is developed of the interaction of the cantilever tip of an atomic force microscope with the sample surface that treats the cantilever and sample as independent systems coupled by a nonlinear force acting between the cantilever tip and a volume element of the sample surface. To maintain equilibrium, the volume element is subjected to a restoring force from the remainder of t...

Knowledge of surface forces is the key to understanding a large number of processes in fields ranging from physics to material science and biology. The most common method to study surfaces is dynamic atomic force microscopy (AFM). Dynamic AFM has been enormously successful in imaging surface topography, even to atomic resolution, but the force between the AFM tip and the surface remains unknown...

Applications of state-of-the-art atomic force microscopy methods to the elucidation of the surface and near-surface structure of polymeric solids are described. Contact, tapping, force modulation, frictional force, and other modes of atomic force microscopy are described, and recent results are summarized. Conformational and chain order, crystalline order, polymer crystals, lamellar structures,...

The combination of ultrasound with atomic force microscopy (AFM) opens the high lateral resolution of scanning probe techniques to ultrasonics. Atomic force acoustic microscopy (AFAM) and lateral atomic force acoustic microscopy are techniques which use the vibration modes of AFM cantilevers. In the AFAM-mode the cantilever is vibrating in one of its flexural resonances while the sensor tip is ...

Scanning probe microscopy (SPM) has revolutionised high resolution imaging of a wide range of samples. With the introduction of atomic force microscopy (AFM) high resolution images can be obtained without the need for the sample to be placed in a vacuum chamber. Furthermore, modern AFM systems are capable of producing high quality images of samples immersed in a wide range of liquids. Atomic Fo...

Atomic force microscopy (AFM) is a state of the art imaging system that uses a sharp probe to scan backwards and forwards over the surface of an object. The probe tip can have atomic dimensions, meaning that AFM can image the surface of an object at near atomic resolution. Two big advantages of AFM compared to other methods (for example scanning tunneling microscopy) are: the samples in AFM mea...