Phenothiazine and semi-cyanine based colorimetric and fluorescent probes for detection of sulfites in solutions and in living cells.

Four hemicyanine probes for selectively detecting sulfites (HSO3 -/SO3 2-) have been constructed by the condensation reaction of 7-substituted (CN, Br, H and OH) phenothiazine aldehyde with 1-ethyl-2,3,3-trimethylindolium iodide. All four probes show a fast and sensitive response to HSO3 -/SO3 2- via a Michael addition, with a detection limit lower than 40 nM based on monitoring their UV/vis absorption changes. Although all four probes display an increase in fluorescence when responding to HSO3 -/SO3 2-, the increment is larger for the probe with an electron-withdrawing group than the probe with an electron-donating group, except for Br. Thus, among four probes the 7-cyano probe (PI-CN) possesses the largest fluorescent response to HSO3 -/SO3 2-, and the lowest detection limit (7.5 nM). More expediently and easily, a film and a test paper with PI-CN have been prepared to detect HSO3 -/SO3 2- in a sample aqueous solution selectively. Finally, the detection of HSO3 -/SO3 2- by PI-CN in biological environments has been demonstrated by cell imaging.

Printing and impact properties of cationised hollow cellulosic fiber based polyester/cotton composite.

Hollow fibers materials have been potentially used and gaining increasing attention in recent years. In this study, Egyptian hollow fibers have been blended with cotton and polyester wastes at different weft counts using open-end spinning. The blended fabrics were subjected for cationisation followed by printing with reactive and acid dyes. The performance of impact properties of cationised hollow fiber reinforced polyester/cotton hybrid composites was studied. The results demonstrated that the physical and color properties of blended fabrics are greatly influenced by alkali pretreatment and cationisation of hybrid composites as well as the weft counts. The pretreatment decreases the resistance of the waxy layer on the surface of hollow fiber and increased markedly the efficiency of printing. Besides, the pretreatment supplied for hybrid composites accomplished the required color balance that can bring about reasonable fastness properties. These studies provided referential knowledge for printing of hollow cellulosic-based composite materials.

Cellulosic fabrics printing with multifunctional encapsulated phthalocyanine pigment blue using phase separation method.

Aqueous dispersions of citric-acrylate (CAC) oligomer encapsulating C.I. Pigment Blue 15:3 (PB15:3) in the presence of glutaraldhyde were formulated using the phase separation method. FT-IR spectroscopy and centrifuge sedimentation are performed to confirm the encapsulation of pigment into CAC oligomer. The prepared capsules were characterized using thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). The results revealed that the encapsulated pigment had a profound multifunctional impact and minimized the driving force of pigment printing on the cellulosic fabrics. Besides, the encapsulated pigment accelerated the pigment fixation on cellulosic fabrics without drying in one step and reduced the required amount of the binder, compared with the control sample. Furthermore, the printed fabrics exhibited good antibacterial performance against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The presence of the crosslinker could be stabilized the encapsulated pigment on the cellulosic fabrics. Moreover, the light and washing fastness for the printed fabrics using encapsulated pigment are higher than that in case of using control samples.

An approach to the impact of nanoscale vat coloration of cotton on reducing agent account.

Aqueous dispersions of nanoscale vat dyes were successfully prepared through ball milling and ultrasonication of three test dyes in the presence of dispersing agent. Critical factors included the time of ball milling and ultrasonication and the molecular structure of the vat dyes have been studied. These dispersions were characterized by morphological structures with particle size determination and quality was evaluated by shelf-life stability using digital images. The nanoscale vat dyes have been applied in dyeing and printing of cotton to evaluate the effect of nanoscale dispersion on the reducing agent account and the difference of coloration performance of a nanoscale and conventionally dispersed vat dyes. Results showed that use of sodium dodecyl sulfate (SDS) maintained a high stability of dispersion with storage. The size and stability of nanoscale dispersion were greatly influenced by molecular structure of the vat dyes. Ultrasonication was helpful in decreasing average particle size. Nanoscale vat dye dispersions gave a much higher color yield than conventional vat dyes. Fastness properties were excellent for washing effects. It is clear that coloration using nanoscale vat dye dispersions offer a number of advantages in terms of reducing agent requirement, improved appearance and also in environmental protection.

Surface functionalization of viscose and polyester fabrics toward antibacterial and coloration properties.

Nanoparticles have been increasingly used to improve the properties of textile fabrics. Viscose and polyester fabrics are treated with SiO(2) nanoparticle by another technique than the conventional sol-gel method in presence of binder (acrylate based copolymer). The effect of the content of SiO(2) nanoparticle on the physical properties of the treated fabrics such as moisture regain, tensile strength and elongation % were investigated. Furthermore, the antibacterial activity and coloration properties of pretreated fabrics were evaluated. Characterizations of pretreated samples by infrared spectroscopy and scanning electron microscopy were also conducted. The results show that the physical and coloration properties of pretreated samples were improved. The treated viscose fabric showed outstanding antibacterial performance against both Escherichia coli (G-) and Staphylococcus aureus (G+). Excellent durability of the treatment to repeated home laundering toward antibacterial and coloration properties was obtained in presence of binder.