<p>Telah dilakukan penelitian karakterisasi dan uji efektivitas <em>allophane-like</em> untuk adsorpsi ion logam tembaga (Cu). <em>Allophane-like</em> dibuat dengan mencampurkan larutan <em>Tetraethyl Orthosilicate</em> (TEOS) dan <em>Aluminum Nitrate Nonahydrate</em> [Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O] dengan perbandingan 0,5; 0,75; 1; 1,25 dan 1,5. Proses pencampuran dilakukan penambahan NaOH secara bertahap dan dilakukan pengadukan serta pemanasan. Penambahan NaOH dilakukan dengan membuat perbandingan NaOH dan Campuran TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O 3:1. pH campuran larutan yang diperoleh diukur dan pH larutan dibuat menjadi asam (pH 3-4). <em>Allophane-like</em><em> </em>dikarakterisasi dengan spektroskopi infra merah (FTIR), XRD, keasaman, dan luas permukaan. Uji adsorpsi terhadap ion logam tembaga (Cu) dilakukan pada variasi perbandingan TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O 0,5; 0,75; 1; 1,25 dan 1,5, pH larutan tembaga (Cu) 3-7 serta waktu kontak 30-120 menit dengan sistem <em>batch</em>. Hasil penelitian diketahui bahwa <em>allophane-like </em>memiliki gugus fungsi yang sama dengan <em>allophane-</em><em>alam </em>yang ditunjukkan dengan data FTIR yaitu memiliki puncak yang sama pada 3431-3252; 1631; 1071; 785; dan 562-457 cm<sup>-1</sup>. Hasil analisa XRD, keasaman dan luas permukaan menunjukkan karakteristik yang berbeda. Kondisi adsorpsi ion logam tembaga (Cu) terjadi pada variasi perbandingan TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O 1,5, pH 6, waktu kontak 120 menit, persentase penyerapan 41,79% dan kapasitas adsorpsi 0,97865 mg/g.</p><p><strong>Characterization and Effectivity of </strong><strong>Allophane-Like </strong><strong>in</strong><strong> </strong><strong>the Adsorption of</strong><strong> </strong><strong>Metal Ion of Copper (Cu).</strong> The characterization and effectivity testing of allophane-like for adsorption copper (Cu) metal ion has been studied. Allophane-like was prepared by mixing a solution of Tetraethylorthosilicate (TEOS) and Aluminum Nitrate nonahydrate [Al(NO<sub>3</sub>)<sub>3</sub>.9H2O] using ratio of 0.5; 0.75; 1; 1.25 and 1.5. The mixing process was done gradually adding NaOH and stirring and heating. The addition of NaOH was done by making a comparison between NaOH and mixture of TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O in 3:1. The pH of the mixture solution was measured and made acidic solution (pH 3-4). Allophane-like was characterized by infrared spectroscopy (FTIR), XRD, acidity, and surface area. The adsorption evaluation of copper (Cu) metal ion was done on the variation of the composition of TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O in 0.5; 0.75; 1; 1.25 and 1.5, the pH of a solution of copper (Cu) 3-7 and contact time of 30-120 minutes in batch system. The results revealed that the allophane-like has the same functional group with nature allophane indicated by the FTIR data that has the same peak at 3431-3252; 1631; 1071; 785; and 562-457 cm<sup>-1</sup>. XRD analysis results, acidity and surface area showed different characteristics. The best conditions adsorption of copper (Cu) metal ion occured at the composition of TEOS dan Al(NO<sub>3</sub>)<sub>3</sub>.9H<sub>2</sub>O in 1.5, pH 6, the contact time of 120 minutes, the absorption percentage of 41.79% and adsorption capacity of 0.97865 mg/g.</p>
In Situ Synthesis of Alumina Nanoparticles in a Binary Carbonate Salt Eutectic for Enhancing Heat Capacity
