Judul: Density funtional theory dalam sintesis, karakterisasi, dan prediksi aplikasi. Kasus: senyawa Zn-dialkylditiokarbamat rantai panjang
Abstrak: Coordination compounds of dialkyldithiocarbamate have broad applications, e.g. automotive lubricant additives. Coordinated long chain dialkyldithiocarbamate was studied to obtain the better anti-friction and anti-wear. Integration of computation chemistry e.g. density functional theory used to identify reaction mechanisms, to optimize geometry of structure, and to estimate properties of compounds. The aim of this study was to obtain long chain complexes Zn-dialkyldithiocarbamate, to examine their structures, and to estimate their applications using Density Functional Theory methods (DFT). Long chain Zn-dialkyldithiocarbamate was synthesized through reaction between ZnCl2, NaOH, CS2 and secondary amine during 24 hours in room condition. Secondary amine was obtained from LiAlH4 reduction of amide 2o during 24 hours in nitrogen atmospheric. Reaction of long chain amine 1o and long chain acylchloride was used to obtain amide 2o. DFT and instrumentation (FTIR and HPLC) was used to study of mechanism, structure elucidation and its application. The results showed the synthesis of Zn-dibutyldithiocarbamate, dipalmitilamide, dipalmitilamine, Zn-dipalmitildithiocarbamate yields are 90.02%, 90.91%, 47.5%, and 66.49% respectively. The ratio of intensity and wave number for Zndibutyldithiocarbamate from FTIR spectra and DFT calculations wasn’t significantly different at 95% confidence level. According to DFT calculation (B3LYP/ 6-31G*), the carbon-sulfur bonds in Zn-dibutyldithiocarbamate have an average length of 0.1683-0.1743 nm and the ligand “bite” angle S-C-S has a mean value of 116.85o. This result indicates a tetrahedral-shaped Zndibutyldithiocarbamate. Lubricant additives (anti-wear and anti-friction) properties of Zn-dialkyldithiocarbamates was estimated by chemical hardness and absolute electronegativity. Lower electronegativity value is better anti-friction, and lower chemical hardness is better anti-wear. Anti-friction ability of Zndialkyldithiocarbamate is better than Mo-dialkyldithiocarbamate, while anti-wear ability is lower than Zn-dialkiydithiophosphates. Based on electronegativity absolute value of DFT calculations, the Zn-dialkyldithiocarbamate is categorized as superlubricity that can perform in the boundary lubricant system.
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Judul: Kinerja Antikorosi Zink Dialkilditiofosfat Berdasarkan Studi Termodinamika dan Kinetika dengan Teknik Polarisasi Potensiodinamik
Abstrak: Zinc Dialkyldithiophosphates (ZDTP) is lubricant additives and has function as anti-friction, anti-wear, antioxidant, and anti-corrosion. ZDTP Performances as anti-corrosion is measured by potentiodynamic polarization technique. Three types of ZDTP were prepared, based on the alkyl chain length. The Measurement shows that ZDTP 8 has the highest corrosion inhibition affectivity as compared to ZDTP 4 and ZDTP 16. The inhibition affectivity of ZDTP 8 to metal Cu reaching 80% in the concentration 2% of inhibitor solution. This research result also explains the influence of alkyl chain length on the performance of ZDTP as anti-corrosion. Thermodynamic parameter verification shows corrosion spontaneity decrease by the present of inhibitor. Corrosion activation energy with present ZDTP 8 is 38.60 kJ mol-1, the value is bigger than blank activation energy namely 31.14 kJ mol-1. This phenomena shows that decreasing corrosion rate relate with increasing minimum energy of reaction.
Keyword: inhibition affectivity, kinetic, polarization, thermodynamic, ZDTP

Judul: Ornithonyssus Bursa (Berlese, 1888) Famili Macronyssidae yang Menyerang Unggas Dan Penaggulangannnya
Abstrak: Ornithonyssus bursa adalah tungau penghisap darah pada unggas di daerah tropis dan subtropis. Tungau ini relatif kecil, dengan panjang tubuh antara 700-1000 mikron dan lebarnya 250-490 mikron. Tubuhnya bulat berwarna coklat kekuningan sebelum menghisap darh dan berwarna merah setelah menghisap darah dari induk semangnya.
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