Novel thiol-ene hybrid coating for metal protection

Published: 7 April 2016A novel hybrid anticorrosion coating with dual network of inorganic (Si–O–Si) and organic bonds (C–S–C) was prepared on metal through an in situ sol-gel and thiol-ene click reaction. This novel interfacial thin film coating incorporates (3-mercaptopropyl) trimethoxysilane (MPTS) and 1,4-di(vinylimidazolium) butane bisbromide based polymerizable ionic liquid (PIL) to form a thiol-ene based photo-polymerized film, which on subsequent sol-gel reaction forms a thin hybrid interfacial layer on metal surface. On top of this PIL hybrid film, a self-assembled nanophase particle (SNAP) coating was employed to prepare a multilayer thin film coating for better corrosion protection and barrier performance. The novel PIL hybrid film was characterised for structure and properties using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The corrosion protection performance of the multilayer coating was examined using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results reveal that this novel double layer coating on metal offers excellent protection against corrosion and has remarkably improved the barrier effect of the coating.Mona Taghaviksih, Surya Subianto, Naba Kumar Dutta and Namita Roy Choudhur

Taeniasis and Cysticercosis in the Paniai Lakes Area of Irian Jaya

Penyakit taeniasis dan cysticercosis diperkirakan baru masuk ke daerah Paniai dalam tahun 1970. Kasus-kasus pertama telah ditemukan dalam tahun 1971 diantara penderita yang dirawat di RSU F.narotali. Insidensnya terus meningkat sejak waktu itu dan dalam tahun 1975 sejumlah 60-100 penderita dilaporkan setiap bulan dari poliklinik RSU Knarotali. Survey yang diadakan dalam tahun 1973 di kampung-kampung sekitar F.narotali menemukan prevalensi 8 persen taeniasis dan 4,25 persen untuk cysticercosis. Survey ulangan dalam tahun 1975 menemukan suatu prevalensi sebesar 8,2 persen untuk cysticerosis, dan 3,5 persen epilepsi. Meningkatnya jumlah penderita epilepsi di daerah ini kemungkinan besar disebabkan cysticercosis cerebral. Meningkatnya jumlah penderita luka bakar juga berhubungan dengan epilepsi akibat cysticercosis ini. Usaha-USAha untuk memberantas penyakit ini melalui penyuluhan kesehatan, pembangunan jamban keluarga dan pengawasan pemotongan babi sangat sukar dijalankan karena hambatan-hambatan di bidang sosial budaya. Penyakit ini pada babi telah menjalar ke daerah-daerah lain di pegunungan dan kenimbulkan ketegangan-ketegangan sosial. Penelitian lebih lanjut amat dibutuhkan, supaya suatu program pemberantasan yang lebih efektif dapat segera dilaksanakan untuk melindungi penduduk daerah Paniai dan daerah lainnya terhadap penyakit yang cukup berbahaya ini

Math Instructional Media Design Using Computer for Completion of Two-variables Linear Equation System by Elimination Method*

. Science and technology have been rapidly evolved in some fields of knowledge, including mathematics. Such development can contribute to improvements on the learning process that encourage students and teachers to enhance their abilities and performances. In delivering the material on the linear equation system with two variables (SPLDV), the conventional teaching method where teachers become the center of the learning process is still well-practiced. This method would cause the students get bored and have difficulties to understand the concepts they are learning. Therefore, in order to the learning of SPLDV easy, an interesting, interactive media that the students and teachers can apply is necessary. This media is designed using GUI MATLAB and named as students\u27 electronic worksheets (e-LKS). This program is intended to help students in finding and understanding the SPLDV concepts more easily. This program is also expected to improve students\u27 motivation and creativity in learning the material. Based on the test using the System Usability Scale (SUS), the design of interactive mathematics learning media of the linear equation system with Two Variables (SPLDV) gets grade B (excellent), meaning that this learning media is proper to be used for Junior High School students of grade VIII

Composite electrolyte membranes from partially fluorinated polymer and hyperbranched, sulfonated polysulfone

Macromolecular modification of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF) was done with various proportions of sulfonic acid terminated, hyperbranched polysulfone (HPSU) with a view to prepare ion conducting membranes. The PVDF-co-HFP was first chemically modified by dehydrofluorination and chlorosulfonation in order to make the membrane more hydrophilic as well as to introduce unsaturation, which would allow crosslinking of the PVDF-co-HFP matrix to improve the stability of the membrane. The modified samples were characterized for ion exchange capacity, morphology, and performance. The HPSU modified S-PVDF membrane shows good stability and ionic conductivity of 5.1 mS cm⁻¹ at 80 °C and 100% RH for blends containing 20% HPSU, which is higher than the literature values for equivalent blend membranes using Nafion. SEM analysis of the blend membranes containing 15% or more HPSU shows the presence of spherical domains with a size range of 300–800 nm within the membranes, which are believed to be the HPSU-rich area.Surya Subianto, Namita Roy Choudhury and Naba Dutt

Polymeric ionic liquid nanoparticle emulsions as a corrosion inhibitor in anticorrosion coatings

In this contribution, we report the facile preparation of cross-linked polymerizable ionic liquid (PIL)-based nanoparticles via thiol–ene photopolymerization in a miniemulsion. The synthesized PIL nanoparticles with a diameter of about 200 nm were fully characterized with regard to their chemical structures, morphologies, and properties using different techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. To gain an in-depth understanding of the physical and morphological structures of the PIL nanoparticles in an emulsion, small-angle neutron scattering and ultra-small-angle neutron scattering were used. Neutron scattering studies revealed valuable information regarding the formation of cylindrical ionic micelles in the spherical nanoparticles, which is a unique property of this system. Furthermore, the PIL nanoparticle emulsion was utilized as an inhibitor in a self-assembled nanophase particle (SNAP) coating. The corrosion protection ability of the resultant coating was examined using potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the PIL nanoparticle emulsion in the SNAP coating acts as an inhibitor of corrosion and is promising for fabricating advanced coatings with improved barrier function and corrosion protection.Mona Taghavikish, Surya Subianto, Naba Kumar Dutta, Liliana de Campo, Jitendra P. Mata, Christine Rehm, and Namita Roy Choudhur

Clinical Laboratory Parameters Among Adult Males During a Primaquine Chemoprophylaxis Trial in Irian Jaya, Indonesia

Primakuin yang digunakan sebagai profilaksis malaria terbukti efektif dan diterima dengan baik oleh tubuh manusia yang normal terhadap aktivitas enzim 6 glukosa-6 fosfat dehidrogenase (G-6PD). Pemeriksaan laboratoris klinik adalah bagian dari uji coba secara acak dengan kontrol plasebo dalam rangka mengevaluasi penggunaan primakuin sebagai profilaksis pada penduduk transmigran yang tidak kebal di Irian Jaya. Penelitian ini dilakukan terhadap 129 pria Jawa dewasa yang normal G-6PDnya. Pemeriksaan hematologi, fungsi hati dan ginjal, dan pemeriksaan limfosit dilakukan berulang kali selama waktu penelitian profilaksis dilakukan untuk menjamin keamanan dari sukarelawan tersebut dan mengawasi Perubahan yang mungkin terjadi akibat obat profilaksis. Seperti yang diperkirakan, pengguna primakuin tidak menunjukkan gejala peningkatan methemoglobin yang kembali dalam batas normal setelah 7 hari pemberian dosis terakhir. Pada akhir penelitian (12 bulan profilaksis) nilai hematologi, fungsi hati dan ginjal, dan nilai limfosit dari kelompok primakuin sebanding dengan kelompok plasebo, dan berada dalam batas nilai normal untuk orang Indonesia.Hasil penelitian ini memberikan masukan adanya keluhan fisik yang sedikit dari sukarelawan pengguna profilaksis primakuin. Untuk membuktikan hasil penelitian ini dan mempersiapkan penggunaan secara umum primakuin untuk profilaksis malaria, perlu dilakukan uji coba lebih lanjut keamanan primakuin. Di Indonesia, primakuin tidak digunakan sebagai profilaksis dan laporan hasil penelitian ini hendaknya tidak ditafsirkan sebagai laporan keamanan dari primakuin