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Masruroh Masruroh
Jurusan Fisika Fakultas MIPA Universitas Brawijaya Malang

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Effects of Polystyrene Solvent Difference on Morphology of Polystyrene Layers and Viscoelastic Properties of QCM Biosensors Susi Rahayu; Masruroh Masruroh; Djoko H Santjojo; Eka Rahmawati; Lalu A. Didik; Fadli Robiandi; Setyawan P Sakti
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (678.746 KB) | DOI: 10.21776/ub.natural-b.2014.002.04.8

Abstract

In this research, a modified QCM surface was done to improve the performance of QCM biosensors. This modification is done by coating polystyrene (Ps) on a QCM with toluena and chloroform solvents. The polystyrene coating was performed using spin coating technique, the measurement of surface roughness values using non-contact topography measurement system TMS 1200, and the viscoelastic properties was analyzed by using an electrical impedance. The analysis result using TMS 1200 shows morphologies of polystyrene produced with chloroform solvent have groovier and more porous compared to the toluena solvent. The roughness values of Ps surface with choroform and toluena is about 616.52 nm and 578.9 nm, respectively. The different surface roughness both of the solvent is caused by vapor pressure of each solvent. The vapor pressure value of chlorofrom solvent is 0.26 atm and toluena solvent of 0.037 atm. Moreover, using Sauerbrey equation is found mass of deposited ps produced with chloroform solvent is more than the toluena solvent. The mass of the polystyrene deposited on the surface of QCM with chloroform resulted about 2.23 × 10-5 ± 7.59 × 10-7 g and with toluena of 1.16 × 10-5 ±9.23 × 10-8 g.  Furthermore, viscoelastic test show both polystirene layer are still rigid and have approximately 12.23 Ω impedance value. Therefore, the different solvents affect the surface morphologies of Ps.
Effect of Xylene and Tetrahydrofuran Solvent Type on Polystyrene Layer Thickness With Spin Coating Method Eka Rahmawati; Fadli Robiandi; Lalu A Didik; Susi Rahayu; Djoko H Santjojo; Setyawan P Sakti; Masruroh Masruroh
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (748.683 KB) | DOI: 10.21776/ub.natural-b.2014.002.04.9

Abstract

Surface modification of QCM by applying polystyrene (Ps) as a coating layer has been investigated. The PS layer was coated onto QCM sensor by using spin coating method. Polystyrene was dissolved in two different solvents i.e., xylene and Tetrahydrofuran (THF) with various concentration i,e 1%, 2%, 3%, 4%, 5% and the velocity angular of spin coater were 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, dan 4000 rpm. The results show that different solvent result in the difference of thickness of polystyrene coating layer. By calculation with the Sauerbrey equation, the thickness of Ps layer using xylene solvent show 0.1 µm, 0.28 µm, 0.35 µm, 0.59 µm, and 0.81 µm. While by using THF, the thickness of each Ps layer are 0.15 µm, 0.43 µm, 0.84 µm, 0.97 µm, 1.28 µm. On the other hand, by applying different velocity of spin coater, the thickness of polystyrene with xylene are 0.486 µm, 0.445 µm, 0.432 µm, 0.350 µm, 0.320 µm, 0,290 µm, respectively. Moreover, the thickness of PS layer by using THF show 1.05 µm, 0.93 µm, 0.87 µm, 0.84 µm, 0.67 µm, 0.52 µm. Vapor pressure of each solvent is considered as the main property of solvent which influence the thickness of coating. The vapor pressure of THF (143 mmHg) is higher than the vapor pressure of xylene (72 mmHg), the thickness Ps layer with THF is thicker than that of by xylene solvents. 
Determination of Polystyrene Layer Thickness and Zinc Phthalocyanine (Znpc) with Modified Sauerbrey Equations and Scanning Electron Microscope (SEM) Lalu A Didik; Eka Rahmawati; Fadli Robiandi; Susi Rahayu; Abdurrouf Abdurrouf; Djoko H. Santjojo; Setyawan P. Sakti; Masruroh Masruroh
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (548.641 KB) | DOI: 10.21776/ub.natural-b.2014.002.04.6

Abstract

The thickness measurement of PS thin films on QCM surface and ZnPc layer on QCM/PS using Sauerbrey equation and Scanning Electron Microscope (SEM) has been investigated. Calculation result using a modified Sauerbrey equation show the thickness of PS layer and ZnPc one are 0,45 μm and  0,0676 μm respectively. Additionally the thickness measurement by using SEM shows the thickness of PS  layer is 5,33 μm and the  thickness of ZnPc layer is 10,44 μm. The differences thickness between Sauerbrey equation and SEM topograph is due to layers porosity. The topography of thin films produced by the secondary electron beam scanning allows to get a magnification of SEM image so that it can be measured directly. While the thickness calculation using the Sauerbrey equation is based on the change in the resonance frequency of QCM.
Effect of Deposition Rate on Morphology of Zinc Phthalocyanine Layer (ZnPc) on Polystyrene Surface / QCM with Vacuum Evaporation Process Fadli Robiandi; Lalu A Didik; Eka Rahmawati; Susi Rahayu; Masruroh Masruroh; Setyawan P. Sakti; Djoko H Santjojo
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (686.534 KB) | DOI: 10.21776/ub.natural-b.2014.002.04.7

Abstract

Deposition of zinc phthalocyanine (ZnPc) layer on top polistiren surface by vacuum evaporation method has been investigated. PS layer was coated on QCM surface by spin coater and ZnPc layer was deposited on its surface by vacuum evaporator with three variation of deposition rate, i.e 1.39 ´ 10-4, 8.08 ´ 10-2 dan 7,41 ´ 10-1 μm/s. The morphology and surface roughness of ZnPc layer was observed by scanning electron microscope (SEM) and non-contact topography measurement system TMS-1200 TopMap. SEM image of ZnPc layer with deposition rate of 1.39 ´ 10-4, 8.08 ´ 10-2 and 7.41 ´ 10-1 μm/s shows porous and fibre like structure. The size of pores and fibre structures of ZnPc layer that produced by deposition rates of 1.39 x10-4 and 8.08 x10-2 μm/s is smaller than size of pores and fibre that produced by 7.41 ´ 10-1 μm/s. Moreover, increasing the deposition rate result a lot of ZnPc molecules make a bonding as fibrous result in the volume of fibrous increasing. Moreover, the increasing fibre size result pores volume increase. Therefore deposition rate can affect surface roughness, and roughness value is proportional to morphology of ZnPc layer. Based on result of TMS-1200 TopMap, the highest roughness level is 1310 nm, it’s found on the ZnPc layer that produced by deposition rate of 7,41 ´ 10-1 μm/s.