TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The process further comprises: crosslinking the polybenzoxazole membrane; and coating a selective layer surface of the polybenzoxazole membrane with a thin layer of a material comprising a polysiloxane, a fluoro-polymer, a thermally curable silicone rubber or a UV radiation curable epoxy silicone. The crosslinking is carried out by UV crosslinking of the polybenzoxazole membrane, where the polybenzoxazole membrane comprises UV crosslinkable functional groups. The polybenzoxazole membrane is fabricated into a geometry of flat sheet, spiral wound, disk, tube, hollow fiber or thin film composite. Preferred Components: The polybenzoxazole membrane comprises repeating units of heteroaryl compounds of formula (I). The poly(o-hydroxy amide) polymer comprises many first repeating units of hydroxyaryl amine compounds of formula (II).Ar1 = phenyl, biphenyl or a group of formula (a1);R = -C((CF3)2)-, -C((CH3)2)-, -S((=O)2)-, -O- or -S-;Ar2 = phenoxybenzene, diphenyl-methanone, benzenesulfonylbenzene, (2,2,2-trifluoro-1-phenyl-1-(trifluoromethyl)ethyl)benzene, (1-methyl-1-phenyl-ethyl)benzene, 1-(1-methyl-1-(4-phenoxyphenyl)ethyl)-4-phenoxy-benzene, naphthyl, phenylsulfanylbenzene, 1,4-diphenoxy-benzene, phenyl, biphenyl or 2-benzoyloxyethyl benzoate groups; andAr3 = 1,3-dihydroxybenzyl, 4,4'-dihydroxybiphenyl or a group of formula (b1). EXAMPLE - A three-neck round-bottom flask (250 ml) was charged with lithium chloride (8 g), 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (APAF, 7.32 g) and N-methyl-2-pyrrolidone (NMP, 100 ml). Once the APAF was fully dissolved, a solution of 4,4'-oxydibenzoyl chloride (ODBC, 5.9 g) in NMP (50 ml) was added dropwise to the APAF solution in the flask under mechanical stirring at -15 degrees C to 0 degrees C. The reaction mixture was continuously stirred for 2 hours at -15 degrees C to 0 degrees C and then overnight at room temperature. The resulting viscous polymer solution was poured slowly into methanol (1000 ml) with stirring. The sticky precipitate formed was redissolved in NMP (50 ml). The NMP solution containing the product was poured slowly into deionized water (1000 ml). The resulting fiber-like precipitate formed was worked up to give aromatic poly(o-hydroxy amide) (PA(APAF-ODBC)) containing pendent -OH functional groups ortho to the amide nitrogen in the polymer backbone. PA(APAF-ODBC) (7.5 g) was dissolved in a solvent mixture of NMP (10 g) and 1,3-dioxolane (5 g). The mixture was mechanically stirred for 2 hours to form a homogeneous casting dope. The resulting homogeneous casting dope was allowed to degas overnight. The PA(APAFODBC) polymer membrane was prepared from the bubble free casting dope on a clean glass plate using a doctor knife with a 20-mil gap. The membrane together with the glass plate was then put into a vacuum oven. The solvents were removed by slowly increasing the vacuum and the temperature of the vacuum oven. Finally, the membrane was dried at 150 degrees C under vacuum for at least 48 hours to completely remove the residual solvents to form PA(APAF-ODBC) polymer membrane. The PA(APAF-ODBC) polymer membrane was thermally heated at 50-350 degrees C at a heating rate of 3 degrees C/minute under nitrogen flow. The membrane was held for 1 hour at 350 degrees C and then cooled down to 50 degrees C at a heating rate of 3 degrees C/minute under nitrogen flow, to obtain polybenzoxazole polymer membrane PBO(APAF-ODBC).