Hongjuan Zhang

Functional modification of cellulose fabrics with phthalocyanine derivatives and the UV light-induced antibacterial performance

Cellulose fabrics were modified with a derivative of copper phthalocyanine (Reactive Blue C.I. 21) by dyeing method. The modified cellulose fabrics exhibited important photoactive property, such as the hydroxyl radicals-generating ability. The UV-vis spectrum, exhaustion rate, fixation rate and grafting quantity of Reactive Blue 21 on the cellulose fabrics were measured and calculated. The chemical structure and morphology of the modified cellulose were characterized. The amount of the produced hydroxyl radicals was measured and the photoactive mechanism was discussed. The UV light-induced antibacterial performance of the modified materials was measured. The modified cellulose exhibited photo-induced antibacterial activity against both Staphylococcus aureus and Escherichia coli.

Dyeing properties of the disperse dyes containing cyano group based on benzisothiazole for polyester fabrics under alkali condition

One step dyeing of polyethylene terephthalate (PET) fabrics combining pretreatment and dyeing under the alkali condition was developed for cleaner production. One step dyeing of PET fabrics required that the dye used has good acid and alkali stability. In this paper, dyeing properties of three azo disperse dyes containing cyano group based on benzisothiazole, 3- (4-N-ethoxyl-N-cyanoethyl -phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D1), 3-(4-N-ethyl-N-cyanoethyl- phenyldiazenyl)- 5-nitro-2,1-benzisothiazole (D2), and 3-(N-benzyl-N-cyanoethyl- phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D3), were investigated under alkali condition. The results showed that polyester fabrics could be well dyed with D1, D2 and D3 under the acid condition. However, D1 was decomposed while dyeing at the alkali solution. D2 and D3 had excellent color yields under the alkali condition. The acid-alkali stability and the structure change were analyzed by UV-vis spectrum and high pressure liquid chromatography (HPLC). Gaussian 09 program package was used to optimize geometry by B3LYP method and 6-31G (d) basis set. The solvation energy of D1 in water was higher than those of D2 and D3. The electron withdrawn effect of the hydroxyl affected the energy gap of HOMO and LUMO orbits. D2 and D3 showed excellent stability in the strong alkali medium. And the dyed polyester fabrics with D2 and D3 at the alkali condition also had good fastness properties.

Synthesis of a novel tetrakisazo navy-blue reactive dye based on DSD acid and its synergistic blackening property

Purpose – The purpose of this paper is to synthesise a tetrakisazo reactive dye and to characterise its dyeing property to meet the demand for better black reactive dyes. Design/methodology/approach – The novel tetrakisazo navy-blue reactive dye based on 4,4′-diaminostilbene-2,2′-disulphonic acid was designed and synthesized. The dyeing behaviour of it on cotton fabric was discussed. The synergistic blackening effect and absorbance spectra were investigated by absorbance and reflectance spectra, K/S and colorimetric data. Findings – The exhaustion and fixation of the designed reactive dye were higher than 20 per cent than those of the commercial reactive dye, CI Reactive Black 5. The novel reactive dye has complementary with Reactive Red SPB and Reactive Yellow C-5R in absorbance spectra from 360 to 700 nm. Three reactive dyes had synergistic effect in colour deepening properties. The dyed cotton fabric possessed high K/S value and low reflectance in the whole visual spectrum range from 360 to 700 nm. Pra...