Preparation of a Cellulose Column for Enhancing the Sensing Efficiency of the Biocide 2-n-Octyl-4-Isothiazolin-3-One

In this study, a cellulose acetate (CA) membrane with pores generated by a water pressure treatment was investigated for its ability to serve as a pretreatment filter device for the detection of 2-n-octyl-4-isothiazolin-3-one (OIT). Pores were generated by applying a water pressure of 8 bar to a membrane manufactured using a CA-based polymer solution. The CA used for the manufacturing was an environment-friendly, low-cost and highly energy-efficient material. Furthermore, since the fabricated porous CA polymeric film possessed many hydrophilic functional groups, it could strongly bind hydrophilic substances while avoiding interaction with hydrophobic substances. OIT, which comprises a hydrophobic bond that forms weak bonds over time, can break down more easily than hydrophilic impurities. The different extents of interaction occurring between either the toxic fungicide OIT or the hydrophilic impurities and the CA film were determined by Fourier-transform infrared (FT-IR) spectroscopy. The physicochemical changes in the resulting membrane, which occurred when the pores were generated, were investigated through scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).

Effect of Ionic Radius in Metal Nitrate on Pore Generation of Cellulose Acetate in Polymer Nanocomposite

To prepare a porous cellulose acetate (CA) for application as a battery separator, Cd(NO₃)₂·4H₂O was utilized with water-pressure as an external physical force. When the CA was complexed with Cd(NO₃)₂·4H₂O and exposed to external water-pressure, the water-flux through the CA was observed, indicating the generation of pores in the polymer. Furthermore, as the hydraulic pressure increased, the water-flux increased proportionally, indicating the possibility of control for the porosity and pore size. Surprisingly, the value above 250 LMH (L/m²h) observed at the ratio of 1:0.35 (mole ratio of CA: Cd(NO₃)₂·4H₂O) was of higher flux than those of CA/other metal nitrate salts (Ni(NO₃)₂ and Mg(NO₃)₂) complexes. The higher value indicated that the larger and abundant pores were generated in the cellulose acetate at the same water-pressure. Thus, it could be thought that the Cd(NO₃)₂·4H₂O salt played a role as a stronger plasticizer than the other metal nitrate salts such as Ni(NO₃)₂ and Mg(NO₃)₂. These results were attributable to the fact that the atomic radius and ionic radius of the Cd were largest among the three elements, resulting in the relatively larger Cd of the Cd(NO₃)₂ that could easily be dissociated into cations and NO₃^- ions. As a result, the free NO₃^- ions could be readily hydrated with water molecules, causing the plasticization effect on the chains of cellulose acetate. The coordinative interactions between the CA and Cd(NO₃)₂·4H₂O were investigated by IR spectroscopy. The change of ionic species in Cd(NO₃)₂·4H₂O was analyzed by Raman spectroscopy.