Mohd Arif Agam

Changes in physical properties and molecular structure of polystyrene nanospheres exposed with daily solar flux

The effects of physical properties and molecular structure of 200 nm polystyrene nanospheres (PSN) coated on silicon wafer exposed with daily solar flux were explored by field emission scanning electron microscope (FE-SEM) and attenuated total reflectance-Fourier transform infrared (ATR-FT-IR) spectrometer. It is revealed that the particles shape of PSN changed from spheric to eight-shaped after solar radiation. Reduction of the size as much as 29.5% after 5 minutes exposure was also observed in PSN particles. Changes in the molecular structure of the PSN particles after solar radiation were observed where some of the phenyl moieties of polystyrene broke down to facilitate carbon-carbon cross linkage bonds. These results demonstrated that the shrinkage of PSN particles is caused by the change of the molecular structure of polystyrene.

Nanosphere Lithography: Fabrication of periodic arrays of nanoholes

Nanosphere Lithography (NSL) is inexpensive, inherently parallel, high-throughput and general material nanofabrication technique [1] where single layer polystyrene nanosphere (PSNs) were used as template. The template created by PSNs can be manipulated by various complimentary techniques such as binary layers of PSNs [2], reactive ion etching (RIE) [3], electron beam radiation [4] and microwave irradiation [5] to create further extension patterning abilities of the basic NSL technique. The nanostructures obtained from NSL technique are found in wide range of researchers and applications such as in photonic, solar cells, biomedical etc [6 – 8]. In this study, the size of PSNs were shrunk by exposing them to O2 plasma with various of time (5 – 30 s). The average diameters of the shrinking PSNs under O2 plasma etching were plotted. The PSNs were found gradually decreases in diameter corresponded to the O2 plasma exposure and the etching rate is found to be in the range of 9.1716 nm/s. The etched PSNs were later used as template to deposit metal particles such as Pt and Au. After lift-off process, the sample with thin film Pt or Au, were later etch again to form uniform periodic nanoholes as can be shown in Fig. 1. The nanoholes were characterized by Field Emission-Scanning Electron Microscopy (FE-SEM).

Review on Material Synthesis and Characterization of Sodium (Na) Super-Ionic Conductor (NASICON)

Sodium (Na) Super Ionic Conductor (NASICON) has general formula Na1+ x Zr2P3- xSi x O12 (0 ≤x ≤ 3) derived from its parent compound, sodium zirconium phosphate NaZr2(PO4)3 (NZP) which belong to a rhombohedral crystal structure. This material consists of three-dimensional structure with interesting features such as low thermal expansion coefficient, thermal stability, gas sensor and nuclear waste immobilization that make it viable for industrial applications. Current study presents comprehensive studies on the synthesis and essential characteristics required to understand the theory behind the mechanism that justifies the study of NASICON structure and its application such as lithium ion rechargeable battery, gas sensor, and nuclear waste immobilization and so on.

UV spectra of amino acid in immobilized at nanoparticles formation through Nanosphere Lithography (NSL) by plasma treatment

Nanosphere lithography, as one of the high-resolution and cost-effective technologies, has attracted much research effort from both industry and academics [1]. It utilizes the self-organization of monodispersed nanospheres as an inverse pattern whose deposition channels are defined by interstitial voids between nanospheres [1]. The size of such deposition channels in the pattern is proportional to the size of the spheres. In this study, the modifying of nanospheres structures by plasma treatments to the fabricated nanoparticles arrays by Nanosphere Lithography (NSL) techniques to create Periodic Particles arrays (PPAs) with different size, shape and orientation. UV spectra of protein that immobilized to the nanoparticles arrays under UV spectrums were studied.

Physical and chemical changes of polystyrene nanospheres irradiated with laser

It has been reported that polymer resist such as PMMA (Polymethyl methacrylate) which is a well known and commonly used polymer resist for fabrication of electronic devices can show zwitter characteristic due to over exposure of electron beam [1]. They tend to change their molecular structure to either become negative or positive resist corresponded to irradiation doses. These characteristic was due to crosslinking and scissors of the PMMA molecular structures, but till now the understanding of crosslinking and scissors of the polymer resist molecular structure due to electron beam exposure were still unknown to researchers [2–5].

Star‐like Patterns from Irradiated Polystyrene Nanospheres

Polystyrene nanospheres with 500 nm in diameter were self‐assembled on silicon oxide surface, which later exposed to electron beam radiation. The radiation doses changed the polystyrene nanospheres chemical properties to become more resistant to organic solvents. Smaller polystyrene dots in star‐like patterns corresponded with the initial polystyrene nanospheres used. It was also found that the star‐like patterns which probably originated from the residue of the irradiated polystyrene nanospheres were depended on the amount of the electron beam dosages.