Cellulose derivative matrix membranes

Cellulose Derivative Matrix. Four possible methods for preparing cellulosic, enzyme membranes are presented ... 

Cellulose is the most abundant biopolymer on earth. It can be used in different applications, namely in the form of fibers, and cellulose can be converted into numerous cellulose derivatives. Cellulose micro- and nanofibers have been the subject of intense research in the field of composites. Cellulose derivatives can show liquid crystalline chiral nematic phases, which can be used for the production of diverse composite systems. All-cellulosic composites based on liquid crystalline cellulosic matrices reinforced by cellulose micro- and nanofibers can show enhanced mechanical properties due to fiber orientation induced by the liquid crystalline matrix. Cellulose-based fibers electrospun from liquid crystalline phases can develop different structures, which are able to mimic the shape of plant tendrils on the nano- and microscale, opening new horizons for ceDulosic membrane applications. 

To overcome these problems, a number of synthetic IPs have been proposed. Among these alternative IPs, sulfonated hydrocarbon polymers have received sig-niflcant attention, owing to their eost effectiveness, ease of fabrication, tunable stiffness, and good ion-transport properties, whieh result from their controllable monomer composition, especially via the manipulation of the block copolymers. Naturally abundant functional biopolymers such as cellulose derivatives and chitosan have been considered for their high ionic conductivity, environmental friendliness, low cost, and ability to form uniform films. Another solution is to embed functional nanoparticles in a polymer matrix to fabricate a high-performance nanocomposite membrane (Jo et al. 2013). 

MicrocrystalUne cellulose (MCC) is mainly used in the pharmaceutical industry as a diluent/binder in tablets for both granulation and direct compression processes. Treating high quality cellulose with hydrochloric acid to the desired level yields purified miCTocrystalline cellulose which is a partially depolymerized cellulose [21]. Membrane controlled systans or monolithic matrix drag delivery systems obtained from cellulose derivatives provide controlled release of drags. Film coating techniques are employed for the manufacture of membrane controlled... 

In this section, the usefulness of cellulose or cellulose derivatives as a membrane matrix and as reinforcement filler is discussed in detail. 

Polytetrafiuoroethylene (PTEE) microporous composite membranes were prepared in a similar way [62] using silica derivatives and ion exchange or iminodiacetate-cellulose resins embedded in the PTEE matrix and is used mainly for protein separation and water purification. 

The secondary compounds or enzymes present in the extracytoplasmic space, e.g., the constituents of the cell wall, either are synthesized at the plasma membrane (like cellulose) or they are secreted into the noncytoplasmic lumen of ER or dictosomes and transported to the extracytoplasmic space by vesicles derived from these organelles (like cell wall matrix polysaccharides and enzymes involved in lignification). 

---