Keterlarutan Selulosa, Pelarut dan Produk Selulosa yang Dijana Semula: Suatu Ulasan

Abstract

Selulosa ialah polimer semula jadi yang boleh diperbaharui dan biasanya ditemui di dalam dinding sel tumbuhan. Interaksi hidrofobik yang kompleks serta sifat amfifilik menyebabkan ia sukar dilarutkan dan seterusnya membataskan penggunaannya secara menyeluruh. Pemahaman kepada struktur kimia dan fiziknya membolehkan proses pelarutan berlaku dengan penggunaan jenis pelarut yang bersesuaian. Namun, pelarut sedia ada bukanlah yang terbaik dan efisien terhadap pelarutan selulosa. Sehingga kini, kajian kepada jenis pelarut dan mekanisme pelarutan masih menjadi topik utama penyelidikan. Selulosa yang terlarut pula boleh dijana semula kepada produk fizikal yang lain, contohnya hidrogel, aerogel, kriogel dan xerogel. Produk yang dijana semula daripada selulosa yang terlarut boleh diacukan kepada pelbagai bentuk yang mempunyai struktur tulang yang kuat dan bersifat hidrofilik, bioserasi dan terbiodegradasi. Potensi dalam aplikasi yang pelbagai serta terbukti sebagai alternatif kepada polimer sintetik menjadikan polimer semula jadi ini berpotensi besar dalam bidang sains dan teknologi. Maka, ulasan kajian terhadap selulosa, jenis pelarut serta produk yang dijana semula daripadanya menjadi fokus dalam penulisan makalah ini.

Drying Regimes on Regenerated Cellulose Films Characteristics and Properties

“…Cellulose is a natural polymer mainly found in plants that exemplifies distinctive properties, such as non-toxic, hydrophilic, and outstanding mechanical and environmentally friendly properties [ 1 , 2 , 3 ]. Cellulose is broadly used as a renewable source in various applications as an alternative to petroleum-based materials such as bioplastic, biofilm, and biomembrane.…”

“…However, its extensive applications do not use native cellulose but rather its modified structure. Even though cellulose is hydrophilic, the strong intra- and intermolecular hydrogen bonding of cellulose macromolecules has made them insoluble in water and a common solvent [ 3 , 4 ]. Thus, one of the most effective routes to dissolve cellulose is via aqueous alkaline/urea [ 3 ].…”

“…Even though cellulose is hydrophilic, the strong intra- and intermolecular hydrogen bonding of cellulose macromolecules has made them insoluble in water and a common solvent [ 3 , 4 ]. Thus, one of the most effective routes to dissolve cellulose is via aqueous alkaline/urea [ 3 ]. The dissolved cellulose can then be regenerated into various products depending on the regeneration process, such as hydrogel, beads, cellulose membrane, etc.…”

“…The dissolving process of cellulose is often accomplished in aqueous media, where the produced regenerated cellulose products are bounteous with the water molecules [ 3 , 5 , 7 ]. Generally, the regenerated cellulose product develops a different molecular arrangement than its precursor, which is differentiated by its lattice structures, later identified as cellulose II, III, IV, and V [ 3 , 7 ]. Among the regenerated cellulose products, regenerated cellulose membrane (RCM) is our primary interest.…”

“…Drying is a typical technique to improve long-term storage, transportation costs, and manageability. In the case of RCMs, drying is required as a key step to meet its targeted applications for thin material technology [ 3 , 6 ]. However, the drying of RCMs is a complex task because it often results in uncontrollable side effects, which meddles with their mechanical performance and physical structure [ 11 , 12 ].…”