Electronic Theses and Dissertation

Telah dilakukan penelitian mengenai pembuatan Elektroda Selektif Ion (ESI) Al3+ berbasis membran poliuretan dengan zat aktif 1,10-fenantrolin. Hasil penelitian menunjukkan sensitivitas dan rentang linear yang baik pada komposisi membran minyak jarak : toluen diisosianat : 1,10-fenantrolin : aseton adalah 37,80 : 18,90 : 43,20 : 0,10 (%b/b), komposisi larutan internal KCl : Al(NO3)3 adalah 0,1 : 0,1 (M). Analisis Fourier transform infrared (FTIR) menunjukkan puncak pada bilangan gelombang 3390 cm-1
adanya ikatan uretan. Modifikasi membran poliuretan (PU) lebih lanjut menggunakan 1,10- fenantrolin dibuktikan dengan munculnya puncak gugus fungsi C=C aromatik dan C-N pada bilangan gelombang 1600 cm-1 dan 1325 cm-1. Analisis X-Ray diffraction (XRD) menunjukkan penurunan derajat kristalinitas PU, Membran PU/Fen, dan PU/Fen/Al. Analisis scanning electron microscopy (SEM) menunjukkan membran memiliki lapisan luar padat yang homogen dan berpori pada lapisan dalam. Nilai sensitivitas rata-rata 19,94 ± 0,26 mV/dekade, trayek pengukuran 10-10 -10-4 M dan (R2=0,9976), dan nilai limit deteksi 5,17 x 10-12
M. Kinerja ESI menunjukkan waktu respon 180 detik, pH optimum 6-8 dan waktu hidup elektroda selama 33 hari. Selektivitas ESI Al3+ terhadap ion asing relatif tidak mengganggu dengan nilai Kij

Research on the fabrication of aluminum (III) ion-selective electrodes (ISE) based on polyurethane membranes with active substance 1.10-phenanthroline has been performed. The work showed the ISE has good sensitivity and linear range at membrane composition of castor oil: toluene diisocyanate: 1.10-phenanthroline: acetone is 37.80: 18.90: 0.10: 43.20 (%w/w) using an internal solution composition of KCl: Al(NO3)3 0.1: 0.1 (M). The Fourier transform infrared (FTIR) analysis showed a peak at a wave number of 3390 cm-1 as the formation of urethane bonds. Further membrane modification of polyurethane (PU) using 1,10-phenanthroline was proven by the appearance peak of functional groups of C=C aromatic and C-N at the wave numbers 1600 cm-1 and 1325 cm-1. The X-Ray diffraction (XRD) analysis showed a decrease in the crystallinity degree of PU, PU/phe, and PU/Phe/Al membranes. The scanning electron microscopy (SEM) analysis showed membrane has a homogenous solid outer layer and is porous in the inner layer. The average sensitivity of the ISE is 19.94 ± 0.26 mV/decade with a dynamic range of 10-10 -10-4 M (R2=0.998), and the detection limit is 5.17 x 10-12 M. The performance of ISE determination showed a response time of 190 seconds, pH 6-8, and a lifetime of 33 days, respectively. The effect of foreign ions on the ISE response is indicated by the Kij values below 1. The ISE has good reproducibility and repeatability with an average standard deviation of less than 5%. The percentage of recovery range of this ISE is 99.21-101.57%. Keyword : Ion Selective Electrode, Al3+ Ion, Active Substance 1,10-phenanthroline, Polyurethane, Potentiometric analysis.