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All Journal Physics Student Journal Rekayasa Mesin Journal of Environmental Engineering and Sustainable Technology Natural B JPSE (Journal of Physical Science and Engineering) Jurnal Penelitian Pendidikan IPA (JPPIPA) INDONESIAN JOURNAL OF APPLIED PHYSICS

D. J. Djoko Herry Santjojo

Jurusan Fisika, Fakultas Matematika Dan Ilmu Pengetahuan Alam, Universitas Brawijaya

Author-ID : 370577

Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Decision Sciences, Operations Research & Management Education Electrical & Electronics Engineering Energy Environmental Science Materials Science & Nanotechnology Mechanical Engineering Physics

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Pengaruh Laju Alir terhadap Karakter Plasma dan Sifat Hidrofobisitas Lapisan Polistirena di atas QCM Menggunakan Metode RF dengan DC Bias Abu Bakar; Masruroh Masruroh; Djoko Herry Santjojo
Natural B, Journal of Health and Environmental Sciences Vol 5, No 2 (2019)
Publisher : Natural B, Journal of Health and Environmental Sciences

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Telah dilakukan perlakuan plasma nitrogen menggunakan metode RF dengan DC bias plasma di atas permukaan polistiren dengan variasi laju alir. Tujuan dari penelitian ini untuk mempelajari pengaruh laju alir terhadap sifat hidrofobisitas permukaan polistirena di atas quartz crystal microbalance (QCM) sensor. Polistirena dilarutkan dengan pelarut toluena dan dideposisikan di atas permukaan QCM dengan teknik spin coating. Perlakuan plasma nitrogen dilakukan dengan variasi laju alir 20, 30, 40, 50, 60, 65 dan 70 ml/menit, dan parameter tekanan pada 40 Pa, tegangan RF 90 volt, DC bias 400 volt. Spesies plasma berupa panjang gelombang dan intensitas diukur dengan optical emission spectroscopy (OES) Aurora 400. Sifat hidrofobisitas polistirena diukur dengan contact angle measurement dan gugus fungsi C≡N diobservasi dengan Fourier transform infrared (FTIR). Hasil OES berupa panjang gelombang dan intensitas dicocokkan dengan NIST atomic database, dan didapatkan spesies plasma paling dominan yang terdeteksi merupakan spesies radikal atom N pada panjang gelombang 388 nm dan 424 nm, dan NIII ( ) pada panjang gelombang 334 nm. Hasil pengukuran sudut kontak mengalami kecenderungan perubahan yaitu sudut kontak naik sampai laju alir 50 ml/menit dan turun sampai 70 ml/menit. Nilai perubahan sudut kontak untuk pengaruh laju alir menunjukkan nilai kurang dari 90°, sehingga permukaan bersifat hidrofilik. Hasil observasi dengan FTIR ditemukan gugus fungsi C≡N pada permukaan polistirena setelah dilakukan perlakuan plasma. Gugus Fungsi C≡N terbentuk dikarenakan interaksi spesies plasma berupa radikal atom N dan ion N2+ yang menumbuk permukaan polistirena. Gugus fungsi C≡N bersifat polar sehingga memberikan perubahan pada sifat hidrofobisitas permukaan polistirena.

Preparation of Chitosan-Fe3O4 Nanoparticles by Ex-Situ Co-Precipitation Using Tripolyphosphate / Sulfate as Crosslinker and Characterization Using XRD Ika Oktavia Wulandari; Akhmad Sabarudin; Djoko Herry Santjojo
Natural B, Journal of Health and Environmental Sciences Vol 3, No 3 (2016)
Publisher : Natural B, Journal of Health and Environmental Sciences

Magnetic nanoparticles of Fe3O4 was synthesized in this research by using ex-situ copresipitation method followed by surface modification with crosslinked chitosan along with trypolyphospate (TPP) and sulfate crosslinking agents. The Fe3O4 materials were formed from FeCl2.H2O and FeCl3.6H2O with 1:2 ratio under alkaline condition. Surface modification processes were conducted by mixing chitosan solution with purified Fe3O4 yielding a ferrogel solution as a product. Here, the crosslinker agents, TPP and sulfate, were added to the mixture to make a crosslinking compounds. In these processes, the chitosan-Fe3O4 crystallite size were affected by composition ratio and crosslinking time which will be proven by using x-ray diffraction (XRD) and modified Debye-Scherrer methods. The results showed that, on highest ratios between chitosan and Fe3O4 as well as TPP/sulfate crosslinker, gave the smallest size of crystallite of chitosan-Fe3O4. Furthermore, the more time of crosslinking process caused crystallite size of chitosan-Fe3O4 became much smaller.

Study of Stearic Acid Layer (SA) Microstructure on Surface Quartz Crystal Microbalance (QCM) Sensors Nurramdaniyah Nurramdaniyah; Masdiana Padega; Djoko Herry Santjojo; Setyawan P. Sakti; Masruroh Masruroh
Natural B, Journal of Health and Environmental Sciences Vol 4, No 2 (2017)
Publisher : Natural B, Journal of Health and Environmental Sciences

In the development of QCM-based biosensor sensors, the sensor surface is a very important part because it determine how the surface interacting with its environment especially during the immobilization of biomolecules process. In the utilization of QCM as biomolecule detecting biosensor, it is necessary to coat the polymer material on the surface of QCM. A stearic acid layer is used as an immobilization matrix layer because stearic acid has both polar and non polar properties so it can interact with biomolecules. The stearic acid layer is deposited on the polystyrene surface using a vacuum evaporation method. A study of the microstructure of the stearic acid coating was conducted to determine the possibility of the deposited stearic acid layer used as the matrix layer. In this research, microstructural study of layers of the stearic acid by using Scanning Electron Microscope (SEM) was carried out to find out the surface morphology of stearic acid. X-Ray Difraction (XRD) measurements were conducted to identify the crystal structure of stearic acid while Fourier Transform Infrared (FTIR) measurements were used to determine the stearic acid functional group. The Scanning Electron Microscope (SEM) results show the surface of the cavity and pore layers of the polystyrene layer was coated with white fibers homogeneously deposited on the surface of QCM / Polystyrene. Furthermore, the X-Ray Difraction (XRD) results showing a spectrum peak at an angle of 2q = 26,66° indicates the existence of stearic acid crystals. Whereas, the measurement results of the Fourier Transform Infrared (FTIR) indicate the appearance of C-H functional groups at a wavelength value of 3600-2600 cm-1 which indicates the functionality of the stearic acid layer.

Preparation of Chitosan-Fe3O4 Nanoparticles by In-situ Co-Precipitation Using Tripolyphosphate / Citrate as Crosslinker and Characterization Using XRD Vita Tria Mardila; Akhmad Sabarudin; Djoko Herry Santjojo
Natural B, Journal of Health and Environmental Sciences Vol 3, No 3 (2016)
Publisher : Natural B, Journal of Health and Environmental Sciences

Chitosan-Fe3O4 nanoparticles have been synthesized in a one pot reaction by combine TPP: citrate as crosslinker. The method was in-situ co-precipitation of iron salts in the presence of chitosan and crosslinker. The aim of this study was to determine the effect of preparation process towards chitosan-Fe3O4 nanoparticles characteristics which was prepared on several preparation condition: chitosan:Fe(II):Fe(III) ratio, TPP:citrate ratio, and crosslinking time. The crystallite sizes of the Fe3O4 and chitosan- Fe3O4 nanoparticles was obtained from modified Debye Scherrer equation using data from XRD analysis. The crystallite size of the bare-Fe3O4 and chitosan-Fe3O4 nanoparticles were found to be about 6.22 and 9.49 nm, respectively. XRD analysis results shown that beside Fe3O4 phases there was γ-Fe2O3 phase due to the oxidation of Fe3O4.The crystallite sizes and the percentage of Fe3O4 decreases with increasing number of chitosan coating the Fe3O4 and the length of crosslinking time

PFRET Measurements Using Sensitized Emission Methods in Observation of Calcium Changes in Oocytes Nathania Nanasari; Djoko Herry Santjojo; Chomsin Sulistiya Widodo; Hari Soepriandono
Natural B, Journal of Health and Environmental Sciences Vol 2, No 4 (2014)
Publisher : Natural B, Journal of Health and Environmental Sciences

Fluorescence Resonance Energy Transfer (FRET) is a process of non-radiative energy transfer from donor molecule to an acceptor. We expect to know the quantitative FRET measurements in immature and mature goat oocyte with the presence of calcium. FRET was detected using a laser scanning confocal microscope. We assume that calcium as a donor and fluo-3 as an acceptor. The methods of sensitized emission have been used for quantitative FRET measurement. We also describe the precision FRET (PFRET) data analysis. The value of PFRET describe the presence of calsium in immature and mature oocytes. For these immature and mature oocytes, the results of PFRET are 622,5 and 754,57 respectively. Mature oocyte has more calsium than immature oocyte.

Co-Authors abdurrouf Abdurrouf Abu Bakar Agus Naba Akhmad Sabarudin Arinto Y.P. Wardoyo Budy Wiryawan Chomsin Sulistiya Widodo Edi Purnama Hari Soepriandono Hartatiek, Hartatiek Iin Hidayanti Wulansari Ika Oktavia Wulandari Ikhsani, Ridha N. Inggita I.H. Putri Masdiana Padega Masruroh MASRUROH Masruroh Masruroh Masruroh Masruroh Masruroh Masruroh Masruroh Masruroh Maulia Ingganis Wuriantika Moh Rifqi Nawafi Muhammad Fadlil Khoironi Muhammad Nurhuda Nada Shofura Faradyana Nathania Nanasari Norhayati Ahmad Nurramdaniyah Nurramdaniyah rahmatia putri Ratih Endah Sutantri Renaldo Apriandi Kasa Ridwan Awalin Rizky Benny Relado, Rizky Benny Sakti, Setyawan P. Setyawan P. Sakti Unggul P Juswono Unggul Pundjung Juswono Vita Tria Mardila Winarto Winarto Windajanti, Josephine Maria Yudyanto Yudyanto

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