Acetalizations, asymmetric

Show how the water flux and salt rejection would change with upstream pressure for a perfect cellulose acetate asymmetric membrane and a feed with an osmotic pressure of 20 atm. Use the dilfusivity and solubility values for NaCL (fl) Calculate the internal pressure drop for an oxygen-nitrogen hollow-fiber separator that has 600 pm outside diameter and 400 pm inside diameter fibers 1.0 m long. When = 751by/in. abs and = 15Iby/in. abs, the permeate flux is... 

Intramolecular haloetherification of ene- and diene-acetals Asymmetric synthesis involving chiral oxonium ion intermediates 12SL825. lodination of aromatic and heteroaromatic compounds in water as an eco-friendly solvent 13COS265. 

Optical, scanning and transmission electron micrographs of a commercial cellulose acetate asymmetric membrane are shown in Fig. 5.28. 

Optical, scanning and transmission electron micrographs of a commercial cellulose acetate asymmetric membrane are shown in Fig. 5.26. Each view provides a different perspective on the membrane structure while, together, they give the complete structural model. Specimen preparation for OM and TEM cross sections was by microtomy of embedded membrane strips using a method developed to limit structural collapse (Section 4.3.4). An optical micrograph (Fig. 5.26A)... 

In our literature, we studied three kinds of RO membranes a cellulose acetate asymmetric membrane (SC-3000), a cross-linked N-substituted polyamide composite membrane... 

Idris, A. and Yet, L. K. 2006. The effect of different molecular weight PEG additives on cellulose acetate asymmetric dialysis membrane performance. J. Memb. Sci. 280 920-927. 

In 1963, Loeb and Souriiajan successfully developed the first cellulose acetate asymmetric membrane through the phase inversion technique [ 1]. The developed membrane exhibited higher permeability and separation, thus making the RO separation process possible and practical Since then, phase inversion has become the most important technique of manbrane fabrication for various applications. Advantages of phase inversion over other manbrane fabrication techniques include its ability to produce membranes with a wide range of pore size (0.001-10 xm) and the flexibility of material selection. 

---