Fungsionalisasi Material Magnetik Alam Terlapis Silika dengan Organosilan untuk Adsorpsi Kloramfenikol dan Siprofloksasin
Johnson Nune Naat, Prof. Dr.rer.nat. Nuryono, M.S.
2025 | Disertasi | S3 Ilmu Kimia
Dua senyawa antiobiotik, yaitu kloramfenikol (CAP) dan
siprofloksasin (CIP), banyak digunakan dalam akuakultur, namun penggunaan yang
berlebihan menimbulkan resistensi bakteri dan residu baik pada ikan maupun
lingkungan. Upaya penghilangan antibiotik tersebut dengan adsorben magnetik
yang efektif, mudah dipisahkan dan dapat digunakan kembali perlu dilakukan.
Untuk itu, penelitian ini bertujuan mensintesis material magnetik terlapis
silika terfungsionalisasi gugus hidrofobik organosilan untuk mengadsorpsi CAP
dan CIP.
Tahapan penelitian yang dilakukan meliputi isolasi
material magnetik alam (MMA), ekstraksi silika (SiO2) dari pasir,
dan fungsionalisasi MMA terlapis SiO2 dengan gugus hidrofobik
organosilan (MMA@SiO2/organosilan). Perbandingan jumlah mol
organosilan terhadap berat 1 g MMA@SiO2 divariasi, sedangkan
organosilan yang dikaji meliputi metiltrimetoksisilan (MTMS, C1), oktiltrimetoksisilan
(OTMS, C8), heksadesiltrimetoksisilan (HDTMS, C16), dan
trimetoksi[3-(fenilamino)propil]silan (TMPS, FA). Materials yang dihasilkan
dikarakterisasi dengan FTIR, XRF, XRD, SEM-EDX, VSM, BET. Adsorpsi CAP dan CIP
dilakukan dalam sistem batch dengan kondisi (pH, waktu dan konsentrasi)
yang divariasi. Kandungan CAP dan CIP dalam larutan sebelum dan setelah
adsorpsi dianalisis dengan spektroskopi UV/Vis. Karakteristik adsorpsi CAP dan
CIP meliputi kinetika, isoterm dan termodinamika adsorpsi dievaluasi.
Hasil penelitian menunjukkan bahwa karakterisasi dengan
FTIR, XRF, XRD, SEM-EDX mapping, VSM,
dan BET pada keempat jenis adsorben MMA@SiO2/C1, MMA@SiO2/C8,
MMA@SiO2/C16, dan MMA@SiO2/FA mengkonfirmasi keberhasilan
sintesis. Semakin panjang rantai atom karbon dan semakin besar jumlah mmol
organosilan yang ditambahkan, semakin tinggi sifat hidrofobisitas material
hasil sintesis. Kapasitas adsorpsi CAP dan CIP menurun seiring dengan
bertambahnya panjang rantai atom karbon. Urutan kapasitas adsorpsi CAP adalah MMA@SiO2/C1(3)
(58,46 mg/g) > MMA@SiO2/C8(3) (56,44 mg/g) > MMA@SiO2/C16(3)
(39,13 mg/g), sedangkan kapasitas adsorpsi CIP adalah MMA@SiO2/C1(3)
(106,81 mg/g) > MMA@SiO2/C8(3) (87,93 mg/g) > MMA@SiO2/C16(3)
(59,54 mg/g). Kapasitas adsorpsi CAP dan CIP pada MMA@SiO2/FA(3)
masing-masing sebesar 87,31 mg/g dan 161,17 mg/g, lebih tinggi dibandingkan dengan modifikasi gugus
alifatik. Material magnetik alam yang difungsionalisasi dengan organosilan
menunjukkan potensinya untuk adsorpsi dan desorpsi antibiotik.
Two antibiotics compounds, namely chloramphenicol (CAP)
and ciprofloxacin (CIP), are widely used in aquaculture; however, their
excessive use leads to bacterial resistance and the accumulation of residues in
both fish and the surrounding environment. Therefore, efforts to remove these
antibiotics using an effective magnetic adsorbent that is easily separable and
reusable are necessary. This study aimed to synthesize silica-coated magnetic
materials functionalized with hydrophobic organosilane groups for the
adsorption of CAP and CIP.
The
research stages included the isolation of natural magnetic material (MMA),
silica (SiO2) extraction from sand, and functionalization of
silica-coated MMA with hydrophobic organosilanes. The molar ratios of
organosilanes per 1 g of MMA@SiO2 were varied, and the organosilanes
examined were methyltrimethoxysilane (MTMS, C1), octyltrimethoxysilane (OTMS,
C8), hexadecyltrimethoxysilane (HDTMS, C16), and
trimethoxy[3-(phenylamino)propyl]silane (TMPS, FA). The resulting materials
were characterized using FTIR, XRF, XRD, SEM–EDX, VSM, and BET analyses.
Adsorption of CAP and CIP was carried out in a batch system under varied pH,
contact time, and initial concentration. The concentrations of CAP and CIP
before and after adsorption were determined using UV–Vis spectroscopy, and
adsorption characteristics including kinetics, isotherms, and
thermodynamics—were evaluated.
The results showed that FTIR, XRF, XRD, SEM–EDX mapping, VSM, and BET confirmed the successful synthesis of the four adsorbents MMA@SiO2/C1, MMA@SiO2/C8, MMA@SiO2/C16, and MMA@SiO2/FA. Increasing the alkyl-chain length and organosilane loading enhanced the hydrophobicity of the synthesized materials. The adsorption capacities of CAP and CIP decreased with increasing alkyl-chain length. For CAP, the adsorption capacities followed the order MMA@SiO2/C1(3) (58.46 mg/g) > MMA@SiO2/C8(3) (56.44 mg/g) > MMA@SiO2/C16(3) (39.13 mg/g), while for CIP they followed MMA@SiO2/C1(3) (106.81 mg/g) > MMA@SiO2/C8(3) (87.93 mg/g) > MMA@SiO2/C16(3) (59.54 mg/g). The adsorption capacities of CAP and CIP on MMA@SiO2/FA(3) are 87.31 mg/g and 161.17 mg/g, respectively, which are higher than those obtained with aliphatic group modification. Overall, natural magnetic materials functionalized with organosilanes demonstrate promising potential for the adsorption and desorption of antibiotic contaminants.
Kata Kunci : Material magnetik alam, silika, organosilan, kloramfenikol, siproflokasin
