Sintesis pigmen hematit (α-Fe2O3) dari limbah bubut besi dengan variasi waktu sonikasi menggunakan metode presipitasi-sonikasi

INDONESIA:

Serbuk limbah besi yang dihasilkan industri bubut besi berpotensi sebagai bahan baku dalam sintesis pigmen hematit, hal ini dikarenakan kadar besi yang dimiliki cukup tinggi. Pigmen hematit mempunyai banyak keunggulan salah satunya sifat antiswelling yang mampu mempertahankan dimensi kayu. Sintesis pigmen hematit dilakukan menggunakan metode presipitasi-sonikasi-kalsinasi.

Tahapan presipitasi menggunakan larutan ammonium hidroksida sebagai agen pengendap. Tahapan sonikasi dilakukan pada waktu yang berbeda menggunakan template PEG-6000. Tahapan akhir yaitu kalsinasi pada suhu 750 °C selama 3 jam. Penelitian dilakukan untuk mengetahui pengaruh waktu sonikasi terhadap ukuran kristal, warna pigmen, morfologi, dan komposisi pigmen hasil sintesis serta daya swelling terhadap kayu. Sampel hasil sintesis dikarakterisasi menggunakan difraksi sinar-X (XRD), color reader, dan SEM-EDX.

Data hasil XRD dan color reader menujukkan fasa ferrihidrit setelah proses presipitasi dan berubah menjadi hematit saat proses kalsinasi dengan peningkatan derajat kristalinilita. Sampel dengan sonikasi 90 menit memiliki derajat kristalinitas tertinggi. Hasil color reader menujukkan warna keseluruhan sampel sesuai standar dengan tingkat kecerahan dan kemerahan yang semakin menurun dengan bertambahnya waktu. Hasil SEM menujukkan morfologi tidak seragam dengan ukuran partikel yang semakin kecil seiring bertambahnya waktu sonikasi. Hasil EDX menunjukkan pigmen hematit masih mengandung pengotor berupa unsur karbon. Uji swelling menujukkan stabilitas tertinggi terdapat pada kayu terpigmentasi hematit sebanyak 30 mg.

ENGLISH:

Iron lathe waste powder produced by the iron lathe industry has the potential as a raw material in the synthesis of hematite pigments, this is because of the iron content is high enough. Hematite pigments have many advantages, one of them is anti-swelling properties that can maintain the dimensions of wood. Hematite pigment synthesis was carried out using the precipitation-sonication-calcination method.

Ammonium hydroxide solution was used in the precipitation stage as a precipitating agent. Stages of sonication were performed at different times using the
PEG-6000 template. The final stage was calcination at 750 °C for 3 hours. The research was conducted to determine the effect of sonication time on crystal size, pigment color, morphology, and composition of pigmented synthesis and swelling power on wood.

Synthesized samples were characterized using X-ray diffraction (XRD), color reader, and SEM-EDX. Data from the XRD and color reader showed the ferrihydrite phase after the precipitation stages and after the calcination stages turn into the hematite phase and increase the crystallinity of the sample. Samples with 90 minutes sonication had the highest degree of crystallinity. The result of the color reader showed the overall color of the sample according to the standard with the brightness and redness level which decreases with increasing sonication time. The result of SEM showed non-uniform morphology with smaller particle sizes along increasing sonication time. EDX result showed that hematite pigments still contain impurities in the form of carbon elements. The swelling test showed hematite pigment can decrease swelling on wood and the highest stability of wood used hematite 30 mg.