scholarly journals Modification of Chitosan Membranes via Methane Ion Beam

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2292
Author(s):  
Nasim Gholami ◽  
Babak Jaleh ◽  
Reza Golbedaghi ◽  
Majid Mojtahedzadeh Larijani ◽  
Pikul Wanichapichart ◽  
...  

Chitosan has been used for biomedical applications in recent years, primarily because of its biocompatibility. A chitosan membrane with a 30 μm thickness was prepared and investigated for its surface modification using methane ions. Methane ions were implanted into the chitosan membrane using a Kaufman ion source; bombardment was accomplished using three accelerating voltages of ion beams—30, 55, and 80 kV. The influence of the ion bombardment on morphology, crystallinity, and hydrophilicity was investigated. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy analysis showed that a triplet bond appeared after the implantation of methane ions (acceleration voltage: 80 kV), culminating in the creation of a more amorphous membrane structure. The analyses of atomic force microscopy (AFM) images showed that, with the increase in bombardment energy, the roughness of the surface changed. These results revealed that ion bombardment improved the hydrophilicity of the membranes and the water fluxes of chitosan membranes altered after methane ion bombardment.

2005 ◽  
Vol 107 ◽  
pp. 47-50 ◽  
Author(s):  
S. Sangyuenyongpipat ◽  
Thiraphat Vilaithong ◽  
L.D. Yu ◽  
Rattikorn Yimnirun ◽  
Pisith Singjai ◽  
...  

The interaction between ion beam and biological cells has been studied to apply ionbeam- induced mutation to breeding of crops and gene transfer in cells. Formation of micro-craters has been observed after ion bombardment of plant cells and they are suspected to act as pathways for exogenous macromolecule transfer in the cells. A technique of in-situ atomic force microscopy (AFM) in the ion beam line is being developed to observe ion bombardment effects on cell surface morphology during ion bombardment. A commercial AFM is designed to place inside the target chamber of the bioengineering ion beam line at Chiang Mai University. In order to allow the ion beam to properly bombard the sample without the risk of damaging the scanning tip and affecting normal operation of AFM, geometrical factors have been calculated for tilting the AFM with 35 degree from the normal. In order to avoid vibrations from external sources, mechanical designs have been done for a vibration isolation system. Construction and installation of the in-situ AFM facility to the beam line have been completed and are reported in details.


2012 ◽  
Vol 1421 ◽  
Author(s):  
Russell J. Bailey ◽  
Remco Geurts ◽  
Debbie J. Stokes ◽  
Frank de Jong ◽  
Asa H. Barber

ABSTRACTThe mechanical behavior of nanocomposites is critically dependent on their structural composition. In this paper we use Focused Ion Beam (FIB) microscopy to prepare surfaces from a layered polymer nanocomposite for investigation using phase contrast atomic force microscopy (AFM). Phase contrast AFM provides mechanical information on the surface examined and, by combining with the sequential cross-sectioning of FIB, can extend the phase contract AFM into three dimensions.


2009 ◽  
Vol 1228 ◽  
Author(s):  
Hao Wang ◽  
Greg C. Hartman ◽  
Joshua Williams ◽  
Jennifer L. Gray

AbstractThere are many factors that have the potential to limit significant advances in device technology. These include the ability to arrange materials at shrinking dimensions and the ability to successfully integrate new materials with better properties or new functionalities. To overcome these limitations, the development of advanced processing methods that can organize various combinations of materials at nano-scale dimensions with the necessary quality and reliability is required. We have explored using a gallium focused ion beam (FIB) as a method of integrating highly mismatched materials with silicon by creating template patterns directly on Si with nanoscale resolution. These templates are potentially useful as a means of locally controlling topography at nanoscale dimensions or as a means of locally implanting Ga at specific surface sites. We have annealed these templates in vacuum to study the effects of ion dosage on local Ga concentration and topography. We have also investigated the feasibility of creating Ga nanodots using this method that could eventually be converted to GaN through a nitridation process. Atomic force microscopy and electron microscopy characterization of the resulting structures are shown for a variety of patterning and processing conditions.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Emilia Tomaszewska ◽  
Katarzyna Soliwoda ◽  
Kinga Kadziola ◽  
Beata Tkacz-Szczesna ◽  
Grzegorz Celichowski ◽  
...  

Dynamic light scattering is a method that depends on the interaction of light with particles. This method can be used for measurements of narrow particle size distributions especially in the range of 2–500 nm. Sample polydispersity can distort the results, and we could not see the real populations of particles because big particles presented in the sample can screen smaller ones. Although the theory and mathematical basics of DLS technique are already well known, little has been done to determine its limits experimentally. The size and size distribution of artificially prepared polydisperse silver nanoparticles (NPs) colloids were studied using dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) spectroscopy. Polydisperse colloids were prepared based on the mixture of chemically synthesized monodisperse colloids well characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), DLS, and UV-Vis spectroscopy. Analysis of the DLS results obtained for polydisperse colloids reveals that several percent of the volume content of bigger NPs could screen completely the presence of smaller ones. The presented results could be extremely important from nanoparticles metrology point of view and should help to understand experimental data especially for the one who works with DLS and/or UV-Vis only.


2005 ◽  
Vol 864 ◽  
Author(s):  
Bentao Cui ◽  
P. I. Cohen ◽  
A. M. Dabiran

AbatractThe formation of ion induced nanoscale patterns such as ripple, dots or pores can be described by a linear continuum equation consisting of a surface roughening term due to curvature-dependent sputtering or asymmetric attachment of vacancies, and a surface smoothing term due to thermal or ion-induced diffusion. By studying ion-induced dimple volume change using atomic force microscopy, we show a method to measure the ion-roughening coefficient. Using this method, we found the roughening coefficient í was 45 nm2/sec at 730K for initial ion etchings with 300 eV Argon ions. Cathodoluminescence measurements indicated Ga-vacancy formation during ion bombardment. The activation energy for surface relaxation after ion etching was about 0.12 eV as measured by reflection high energy electron diffraction.


1999 ◽  
Vol 562 ◽  
Author(s):  
Stephan Grunow ◽  
Deda Diatezua ◽  
Soon-Cheon Seo ◽  
Timothy Stoner ◽  
Alain E. KaloyerosI

ABSTRACTAs computer chip technologies evolve from aluminum-based metallization schemes to their copper-based counterparts, Electrochemical Deposition (ECD) is emerging as a viable deposition technique for copper (Cu) interconnects. This paper presents the results of a first-pass study to examine the underlying mechanisms that control ECD Cu nucleation, growth kinetics, and post-deposition microstructure evolution (self-annealing), leading to the development and optimization of an ECD Cu process recipe for sub-quarter-micron device generations. The influence of bath composition, current waveform, type and texture of Cu seed layer, and device feature size (scaling effect) on the evolution of film texture, morphology, electrical properties, and fill characteristics was investigated using a manufacturing-worthy ReynoldsTech 8″ wafer plating tool. Resulting films were analyzed by X-ray Diffraction (XRD), four-point resistivity probe, Focused-Ion-Beam Scanning Electron Microscopy (FIB-SEM), and Atomic Force Microscopy (AFM). These investigations identified an optimized process window for the complete fill of aggressive device structures with pure Cu with resistivity ∼ 2.0 μΩ-cm and smooth surface morphology.


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