Electronic Theses and Dissertation

Polyvinylidene Fluoride (PVDF) merupakan material membran multifungsi yang banyak digunakan karena sifatnya yang fleksibel, tahan lama, serta stabil terhadap bahan kimia. Namun, sifat hidrofobik bawaan dari PVDF sering menurunkan fluks air dan efisiensi filtrasi, sehingga diperlukan modifikasi untuk meningkatkan sifat hidrofilik dan ketahanan fouling. Penelitian ini bertujuan untuk meningkatkan kinerja membran PVDF melalui metode hibrida yang mengombinasikan penambahan kalsium klorida (CaCl₂) ke dalam larutan polimer (blending) dan pelapisan natrium alginat (NA) pada permukaan membran. Modifikasi ini diharapkan dapat meningkatkan hidrofilisitas, kemampuan antifouling, dan efisiensi filtrasi membran. Karakterisasi dilakukan menggunakan Fourier Transform Infrared Spectroscopy (FTIR) untuk mengidentifikasi gugus fungsi, Scanning Electron Microscope (SEM) untuk morfologi, Mikroskop 3D laser untuk kekasaran permukaan, serta Water Contact Angle (WCA), porositas, dan ukuran pori untuk mengevaluasi sifat fisik membran. Uji kinerja meliputi pengukuran fluks air murni (PWF), rejeksi asam humus, dan sifat antifouling. Hasil menunjukkan bahwa kombinasi CaCl₂ dan NA berhasil membentuk ikatan silang (crosslinking) yang meningkatkan hidrofilisitas morfologi, serta porositas membran. Nilai contact angle menurun dari 78,08° menjadi 65,46°, porositas meningkat hingga >40%, dan fluks air murni meningkat lebih dari dua kali lipat dibandingkan PVDF murni. Rejeksi asam humus mencapai lebih dari 90%, sementara rasio pemulihan fluks mencapai >96%, menandakan peningkatan signifikan dalam kemampuan antifouling dan efisiensi filtrasi. Secara keseluruhan, metode hibrida CaCl₂-NA terbukti efektif dalam meningkatkan performa membran PVDF.

Polyvinylidene Fluoride (PVDF) is a multifunctional membrane material widely used due to its flexibility, durability, and excellent chemical resistance. However, the inherent hydrophobic nature of PVDF often reduces water flux and filtration efficiency, necessitating surface modification to enhance its hydrophilicity and antifouling resistance. This study aims to improve the performance of PVDF membranes through a hybrid modification method that combines the addition of calcium chloride (CaCl₂) into the polymer solution (blending) and the surface coating of sodium alginate (NA). This modification is expected to enhance the hydrophilicity, antifouling capability, and filtration efficiency of the membrane. Characterization was performed using Fourier Transform Infrared Spectroscopy (FTIR) to identify functional groups, Scanning Electron Microscopy (SEM) to observe surface morphology, 3D laser microscopy to analyze surface roughness, and Water Contact Angle (WCA), porosity, and pore size measurements to evaluate the physical properties of the membranes. Performance evaluation included pure water flux (PWF), humic acid rejection, and antifouling tests. The results showed that the combination of CaCl₂ and NA successfully formed crosslinking interactions that enhanced the membrane’s hydrophilicity, morphology, and porosity. The contact angle decreased from 78.08° to 65,46°, porosity increased to over 40%, and pure water flux more than doubled compared to pristine PVDF. Humic acid rejection exceeded 90%, while the flux recovery ratio (FRR) reached over 96%, indicating significant improvements in antifouling behavior and filtration efficiency. Overall, the hybrid CaCl₂-NA modification proved effective in enhancing the performance of PVDF membranes. The next stage will focus on long-term performance testing to evaluate membrane stability under continuous operation.