PERMEASI KALIUM KLORIDA KE DALAM MEDIA AQUEOUS MELALUI MEMBRAN HIDROGEL PVA-BORAT PADA BERBAGAI PH - Indri Puji Lestari, - (2021)
Pupuk merupakan hal yang sangat penting untuk kebutuhan pertanian, tetapi tidak semua unsur hara pada pupuk dapat terserap oleh tanaman melainkan ada beberapa bagian yang hilang disebabkan larut, menguap, serta adanya proses kimia seperti hidrolisis atau dirusak oleh mikroorganisme. Untuk meningkatkan efektivitas penyerapan nutrisi tanaman, teknologi controlled release fertilizer (CRF) telah diperkenalkan dan diaplikasikan pada bidang pertanian. Pada umumnya matriks yang sering digunakan dalam CRF ialah hidrogel. Oleh karena itu penelitian ini bertujuan untuk, mensintesis membran hidrogel PVA-borat, mengetahui karakteristik membran hidrogel PVA-borat, serta mengetahui pengaruh pH lingkungan terhadap swelling ratio dan laju permeasi pada membran hidrogel PVA-borat. Pada penelitian ini dilakukan (1) sintesis membran hidrogel PVA-borat; (2) karakterisasi membran hidrogel PVA-borat dengan spektrofotometer FTIR; (3) uji swelling ratio membran hidrogel PVA-borat pada berbagai pH, yaitu pH 6, 7 dan 8; (4) uji permeasi KCl melalui membran hidrogel PVA-borat pada pH 6, 7 dan 8. Membran hidrogel PVA-borat hasil sintesis berbentuk lembaran dengan ketebalan 0,11 mm. Karaterisasi FTIR menunjukkan bahwa spektrum antara PVA dan membran hidrogel PVA-borat memiliki kemiripan, dimana borat sebagai crosslinker memberikan interaksi fisik terhadap jaringan crosslinking PVA-borat dan tidak disertai adanya penambahan atau hilangnya gugus fungsi. Pengujian swelling ratio dan permeasi menunjukkan bahwa semakin tinggi pH maka swelling semakin besar dan laju permeasinya semakin cepat. Fertilizer is very important for plant growth, but not all nutrients in fertilizer can be absorbed by plants but there are some parts that are lost due to dissolving, evaporation, and chemical processes such as hydrolysis or being damaged by microorganisms. To increase the effectiveness of plant nutrient absorption, controlled release fertilizer (CRF) technology has been introduced and applied to agriculture. In general, the matrix that is often used in CRF is hydrogel. Therefore, this study aimed to synthesize the PVA-borate hydrogel membrane, to determine the characterization of the PVA-borate hydrogel membrane, and to determine the effect of environmental pH on the swelling ratio and permeation rate of the PVA-borate membrane. In this study, (1) the synthesis of PVA-borate hydrogel membrane; (2) characterization of PVA-borate hydrogel membrane by FTIR spectrophotometer; (3) swelling ratio test of PVA-borate hydrogel membrane at pH 6, 7 and 8; (4) KCl permeation test through PVA-borate hydrogel membrane at pH 6, 7 and 8. The synthetic PVA-borate hydrogel membrane was in the form of a sheet with a thickness of 0.11 mm. FTIR characterization showed that the spectrum between PVA and PVA-borate hydrogel membrane was similar, which means that borate as a crosslinker provides physical and chemical interactions to the PVA-borate crosslinking network, but is not accompanied by the addition or loss of functional groups. The swelling ratio and permeation test showed that the environmental pH had a significant effect on the swelling ratio and the permeation rate of the PVA-borate hydrogel membrane. The higher the pH of the environment, the hydrogel will swell bigger and the permeation rate will be faster.