Abstract: A pore-filled ion exchange polyelectrolyte composite membrane from which the surface ion exchange polyelectrolyte has been removed and a method of manufacturing the same are provided. The ion exchange polyelectrolyte composite membrane exhibits low film resistance and low in-plane-direction swelling degree, and has a smaller film-thickness than a commercial film, and thus, can be used for various purposes. In addition, since the pore-filled ion exchange polyelectrolyte composite membrane is continuously manufactured through a roll-to-roll process, the manufacturing process is simple, and manufacturing costs can be greatly reduced.

Abstract: A grinding wheel includes a plurality of wheel tips. The plurality of wheel tips include a plurality of diamond abrasive grains and a bonding material mixed with the diamond abrasive grains. The plurality of diamond abrasive grains have a ratio of a length in a long axis direction to a width in a short axis direction of 1:2.5 to 1:3.5 and includes edges or vertices having a grinding angle of 90° or less.

Abstract: In a method for purifying highly pure isopropyl alcohol used in a semiconductor cleaning process, diacetone alcohol present in isopropyl alcohol is removed by an adsorption process, and diacetone alcohol, triisopropyl borate, and metal impurities are removed by a distillation process. The purified isopropyl alcohol may have a purity of has the moisture of 10 ppm or less, the triisopropyl boron compound of 50 ppt or less, and each metal of the metal impurities of 20 ppt or less.

Abstract: Provided is a method for purifying waste N-methyl-2-pyrrolidone, the method comprising the steps of: reacting the waste N-methyl-2-pyrrolidone containing an amine compound with an acid anhydride; converting the amine compound into an amide compound; and removing the amide compound by distillation, thereby manufacturing high-purity N-methyl-2-pyrrolidone that can be reused.