The extraction process is a crucial part of the synthesis of Molecularly Imprinted Polymers (MIP). The process will have a significant impact on the number of its cavities that affects the polymers’ ability to recognize targets with the same physical and chemical properties as the analytes. Caffeine polymers have been prepared by the cooling-heating method using methacrylic acid (MAA) as a monomer, ethylene glycol dimethacrylate (EDMA) as a crosslinker, benzoyl peroxide (BPO) as an initiator, and chloroform as a solvent. The resulting caffeine polymer powder was extracted using chloroform, methanol / acetic acid (1:20), and methanol, respectively. Finally, the polymer powder is washed using the aquabidest, which is heated at 60°C. The results of FTIR, XRD, and SEM characterization showed that caffeine concentration was significantly reduced. The number of cavities obtained from caffeine MIP is 604 more than before extracted, which is 132 pieces.

The cooling-heating method was used to successfully synthesize molecularly imprinted polymers on caffeine. Caffeine was used as a template and mixed with chloroform solvent, methacrylic acid as a monomer, ethylene glycol dimethacrylate as a cross-linker, and benzoyl peroxide as an initiator. The solution was stirred for 15 minutes and placed in a vial. Then it was placed in a cooler with a temperature of -5○C for 60 minutes and then inserted into an oven with an increasing temperature at 75○C, 80○C, and 85○C for 3, 2 and 1 hour, respectively. Furthermore, the repeated washing process resulted in solid polymer, which was subjected to template leaching to produce polymers with specific cavities called molecularly imprinted polymers (MIP). The resulting caffeine polymer and MIP were tested using SEM, FTIR, and XRD methods. In addition, the SEM image analysis data showed 388 cavities in the polymer after template leaching, compared to the 121 cavities in the unwashed polymer. This result was supported by the FTIR spectrum analysis which showed that caffeine MIP has a higher transmittance value than the polymer. Therefore, the caffeine concentration was significantly reduced after the leaching process. The XRD spectra showed that caffeine MIP had a smaller halfmaximum diffraction peak width (FWHM) compared to the polymer. Also, the low FWHM value depicted a larger crystalline size in the caffeine MIP compared to the polymer.

Kata kunci:MIP, pendinginan-pemanasan, nano melamin ABSTRAK: Nano polimer berbasis Molecularly Imprinted Polymer (MIP) diproduksi dengan metode pendinginan-pemanasan. Bahan yang digunakan pada penelitian ini adalah melamin. Tujuan dari pembuatan MIP nano melamin adalah untuk memperoleh material sensor dalam pengaplikasiannya. Penelitian ini menggunakan bahan aktif melamin di milling dengan menggunakan alat HEM. Tujuan milling untuk menjadikan serbuk melamin berdimensi nano. Waktu yang digunakan pada proses milling selama 15 menit dengan variasi 61:1. Setelah proses milling selesai dilanjutkan dengan pembuatan polimer melibatkan template nano melamin, methacrylic acid sebagai monomer fungsional, ethylene glycol dimethacrylate sebagai crosslinker, benzoil peroksida sebagai inisiator, dan etanol sebagai pelarutnya disintesis dengan metode pendinginan-pemanasan. Pembuatan non imprinted polymer (NIP) digunakan sebagai polimer kontrol. Proses pembuatan NIP sama seperti pembuatan MIP, tetapi NIP tidak menggunakan bahan aktif melamin. Pada proses pelepasan template melamin berperan penting untuk material sensor. MIP nano melamin, polimer nano melamin, dan NIP yang telah diekstraksi kemudian di karakterisasi dengan uji FTIR, XRD dan SEM. Hasil uji FTIR menunjukkan gugus fungsi nano melamin tidak terlihat pada NIP dibandingkan dengan spektrum MIP, terdapat peningkatan persentase transmitansi. Hal ini disebabkan adanya penurunan konsentrasi nano pada nano melamin setelah di ekstraksi. melamin. Hasil dari uji X-RD menunjukkan bahwa ukuran nano kristal melamin adalah 1,6 nm. Setelah dianalisis dengan software ImageJ, hasil pengujian SEM menunjukkan bahwa jumlah pori yang dicetak adalah 511. Data ini menunjukkan bahwa MIP nano melamin yang diperoleh memiliki potensi aplikasi sebagai material sensor.

This study was conducted to synthesize Fe (III)-IIPs by free radical polymerization using the cooling-heating method. Cooling processat -5◦C for 1 hour, as well as heating at 75◦C, 80◦C, and 85◦C maintained for 3 hours, 2 hours and 1 hour, respectively. The Fe (III)-IIPs synthesis process involved Fe(NO3)3 with an average diameter of 18.23 nm, methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), benzoyl peroxide (BPO) and ethanol, each of which plays a role as an analyte, functional monomer, cross-linker, initiator, and porogen. The result of the polymerization process was a polymer containing ions namely Fe(III) polymer. The ions need to be removed by the extraction process to produce Fe(III)-IIPs, which act as absorbents. Furthermore, the extraction process is very influential in the process of losing ions and the formation of cavities or templates in the polymer body. The number of cavities formed tends to affect the ability of Fe(III)-IIPs to identify the target ion which has similar physical and chemical properties to the shape of the Fe(III)-IIPs cavity. The extraction process was carried out on Fe(III) polymer samples using HCl and HNO3 solutions with varying concentrations of 3 M and 6 M, respectively. The transmission percentage of FTIR analysis showed that for samples of Fe(III)-IIPs HCl 3 M and 6 M were 94.258% and 95.666%, while for Fe(III)-IIPs HNO3 3 M and 6 M were 92.735%, respectively. The largest percentage was shown in the 6 M HCl IIPs sample, which indicated that there were several ions lost from the polymer body after the extraction process. This is also reinforced by the results of the SEM analysis processed with Matlab, which showed 498 cavities with a distribution of voids on a scale of <100 nm, totaling 470.