Merocyanine dyes exhibit interesting changes in absorption spectra with changes in solvent polarity. For example solutions of 1-methyl-4- (oxocyclohexadienylidene) ethylidene -1,4-dihydropyridine (MOED) are yellow, red, violet, or blue, in water, ethanol, acetone or pyridine respectively.1 More striking effects are observed when aqueous solutions are diluted with various proportions of the organic co-solvents such as pyridine. The color varies across the whole spectrum from golden yellow to blue.These characteristic properties of merocyanine dyes in various organic solvents have been extensively studied and correlations between [see PDF file for formula]max and solvent polarity have been determined. In this work the visible absorption have been determined. In this work the visible absorption properties of merocyanine dyes were studied in cationic and anionic surfactants in order to investigate the behaviour of these dyes in micellar system and to use their electronic spectra as probes of the micellar environment. Since the description of the literature and discussion of the experimental results will involve certain terms and concepts from surfactant chemistry, it is necessary to introduce the subject.

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The effect of process conditions, temperature, time and rate of temperature rise, on the exhaustion of disperse dye on polyester yarn under High-Temperature dyeing conditions was investigated. Two ply spun type Dacron 54 polyester yarn was dyed with Disperse Red 60 in 0.5 g/l dye bath concentration using an Ahiba Texomat Dyeing Apparatus under High-Temperature Dyeing conditions. The dyeing process design used, consists of three levels of dyeing temperature (105°C, 120°C, 135°C), four levels of holding time (0 min, 15 min, 30 min, 60 min) and two levels of rate of temperature rise (1ºC/min, 3°C/min). After the dyeing process, the dye concentration in the yarn was obtained through extraction and measured spectrophotometrically. A factorial analysis of variance (ANOVA) test was used to determine whether or not significant differences existed among dyeing process conditions in regard to the dye uptake of the yarn. If significant differences existed, which parameter of process conditions (temperature, time, rate of temperature rise or their interactions) was responsible. The results of this study indicated that a three-way interaction of temperature, time, and rate of temperature rise was responsible for the differences in dye uptake of the yarn. The dye uptake of the yarn increased by increasing dyeing temperature from 105°C to 120°C for all levels of holding time and rate of temperature rise. However, increasing dyeing temperature from 120°C to 135°C, did not increase dye uptake of the yarn. The dye uptake of the yarn increased by increasing holding time from zero to 15 minutes for dyeing temperature of 120°C. However, increasing holding time from 15 to 60 minutes, did not increase dye uptake of the yarn. At the dyeing temperature of 120°C, a slower rate of temperature rise resulted in greater dye uptake of the yarn. It can be concluded that high temperature dyeing of polyester yarn at 120°C for 15 minutes with a rate of temperature rise of 1°C/min was the optimum dyeing process in achieving full exhaustion. / Master of Science

The effects of fiber reactive and direct dyes on certain physical properties (tenacity, elongation, and initial modulus) of cotton fibers were investigated. Raw cotton fiber and raw yarn spun from the same batch of fiber were obtained. Fiber and yarn were processed by scouring, bleaching, and dyeing with both dyes, using an Ahiba Texomat Dyeing Apparatus, and the appropriate chemical systems. Fibers from treated fiber and fibers removed from treated yarns were tested after each treatment step, using an Instron Tensile Tester. The Wilks multivariate F test was used to determine whether or not significant differences existed between sequential treatments, and between fibers treated as fiber or as yarn. When significant differences were indicated, univariate analysis of variance was computed to identify the property(s) responsible. The results of this study indicated that the physical properties of both fiber reactive dyed and direct dyed fibers were not significantly different from each other or from the bleached fiber from which they were dyed. The properties of bleached (and dyed) fibers were significantly different (lower tenacity and elongation, higher initial modulus) from untreated or scoured fibers, indicating that the bleaching step was responsible for most of the changes noted. The properties of fibers treated as fiber were generally different (lower tenacity, higher elongation, lower initial modulus) than those of fibers removed from yarn. / M.S.

Deniers of treated and untreated fibers were determined and the „ results were used in calculations of tenacity and initial modulus. Tensile properties were measured on a constant—rate—of—extension machine. Shrinkage of treated and untreated fibers were measured after they were boiled in water for 15 min. The glass transition temperatures (Tg) were obtained by differential scanning calorimetry. The ratio of the intensities of the CN/CH stretching bands were found by infrared spectroscopy, using the KBr method / Ph. D. / incomplete_metadata

The effect of carrier concentration and dye type on carrier and dye uptake of Dacron type 54 yarn was determined. Disperse Red 60 and Disperse Yellow 54 dyes were used. 0-phenyl phenol was used with six different concentrations of this carrier (0, 1, 2, 3, 4 and 5 gm/l). Spun Dacron type 54 polyester yarn of 490 denier weighing ten grams was obtained. Dyeing was done using the Ahiba Texomat dyeing machine. The standard composite curves and equations were established for both dyes as well as the carrier. The dye in the yarn was extracted with dimethyl formamide as a solvent using the Fisher Shaking Water Bath. To measure the dye and carrier uptake of the polyester yarn, the extraction and dye bath solutions were analyzed spectrophotometrically. A two-way factorial Analysis of Variance (ANOVA) was used to test the hypotheses. The first null hypothesis indicating that there will be no difference in the uptake of disperse dye by polyester fiber due to initial carrier concentration was rejected. The second null hypothesis indicating that there will be no difference in the uptake of disperse dye by the polyester fiber due to dye type was also rejected. The third and fourth null hypotheses of no difference in the carrier uptake of polyester fiber due to initial carrier concentration and dye type respectively were likewise rejected. The results of this study indicated that both carrier concentration and dye type as well as their interaction have a significant effect on dye and carrier uptake of the polyester yarn. / Master of Science

Molecular distillation presents a method of separation for substances of high molecular weights which would suffer thermal decomposition at the higher temperatures that would be required for conventional distillation. In general, the separatory power of molecular stills is poor and in order to obtain relatively pure substances from mixtures, a series of redistillations may have to be performed. The distillation of individual substances under molecular distillation conditions is best characterized by an elimination curve which is a plot of the yield of the substance against the temperature of distillation. Composite curves, similarly, describe the elimination of a mixture of substances. It was the purpose of this investigation to study the distillation characteristics of several anthraquinone dyes by the determination of single and composite elimination curves, and to attempt to separate binary mixtures of dyes by various redistillation techniques. The glass centrifugal molecular still with a five-inch rotor and a ball-jar condensing surface available at the beginning of the investigation was almost completely reconstructed as an all-metal unit employing copper and brass as the materials of construction. Final design included a vacuum-enclosed drive for the rotor. Other modifications included a copper, magnetically-operated feed pump; copper tubing flow lines with silver-soldered connections; copper feed, residue, and distillate reservoir tanks; spark plug leads for heater and motor lead attachments within the vacuum system; feed and residue thermocouples employing copper tubing as part of the copper lead of the copper-constantan hot junction; a silicone gasket for seal of the bell jar to the base plate; a copper feed tube and nozzle; and a vacuum pumping system consisting of two vertical diffusion pumps connected in series and exhausted to two megavac pumps and a hyvac pump to evacuate the distillate tank. Initial tests were made to obtain a constant-yield oil and to standardize an operating technique. A mixture of light and heavy mineral oils was found to be a satisfactory constant-yield oil. Several tests were made using a continuous temperature rise technique in which the distillate fractions were collected as the temperature rose slowly over the collection increment. 1,4-Diethyl-diamineanthraquinone, 1,4-diisopropyldiaminoanthraquinone, and 1,4-dibutyldiaminoanthraquinone dyes were distilled using this method. A discontinuous temperature rise technique replaced the continuous technique when it became evident that this initial technique could not be satisfactorily standardized. Instead of a continuous temperature increase as distillation progressed, the temperature was held constant while fractions were collected for a predetermined time interval required for five nominal passes of the feed across the rotor. A standardized technique was then developed end used for all subsequent tests, The conditions of operation under the technique were as follows: pressure, 6 ± 1 microns of mercury, absolute; rotor speed, 2000 ± 50 revolutions per minute; feed rate, 65 ± 2 milliliters per minute; nominal number of passes of the feed across the rotor for each fraction, 2; and difference between the feed and residue temperatures, 10 degrees Centigrade. The oil solvent, constant-yield oil, was a mixture of 300 milliliters of light mineral oil to 350 milliliters of heavy mineral oil for each test. Three anthraquinone dyes, celanthrene red 3B, 1,4-diethyldiaminoanthraquinone, and 2,6-dimethyldiaminoanthraquinone, were distilled individually using the standardized technique. The elimination curves were plotted and the maxima found to be 121, 152, end 159 degrees Centigrade, respectively. Equal weight binary mixtures of celanthrene red 3B and 1,4-diethyldiaminoanthraquinone, celanthrene red 3B and 2,6-dimethyldiaminoanthraquinone, and 1,4-diethyldiaminoanthraquinone and 2,6-dimethyldiaminoanthraquinone were distilled to study the effect of difference in the temperature interval between elimination maxima on the composite curve. The effect of varying the weight ratio was studied by the distillation of binary mixtures of 2:1, 1:1, and 1:2-1/2 weight ratio of celanthrene red 3B to 1,4-diethyldiaminoanthraquinone. A tertiary mixture of equal weights of the three dyes used in binary mixtures was distilled to note the added complexity of the composite curve. Attempts to separate binary mixtures were made by extractive redistillation in which additional mineral oil was mixed with the cumulative fractions from the original distillation before redistillation and repeated redistillation in which the cumulative fractions were merely redistilled without addition of any more oil. It was concluded from the investigation that each dye in a mixture distills independently of the other dyes preset. The introduction of each two GHZ groups in the 1,4 position of the anthraquinone series was found to increase the elimination maximum by approximately 10 degrees Centigrade. From a study of the composite curves for the various binary mixtures, it was decided that identification of two substances in an unknown mixture was possible if the second substance was in quantity at least 1/6 that of the first substance and had an elimination maximum at least 20 degrees Centigrade different from the first substance. A comparison of the weight per cent of 1,4-diethyldiaminoanthraquinone removed from the mixture with celanthrene red 3B by the two redistillative techniques indicated that extractive redistillation provided better separation than repeated redistillation with 75.5 weight per cent removed from the cumulative fractions up to 140 degrees Centigrade compared to 68.7 and 52.8 weight per cents removed by the first and second redistillations, respectively. / Master of Science

The purpose of the dissertation research was to investigate the effect of cold ammonia gas plasma irradiation on the dyeability of poly(m-phenylene isophthalamide) fibers (Nomex Type 430) with acid dyes. Unmodified Nomex filament yarns were irradiated by ammonia radio frequency glow discharge plasma with constant input power (100 W) and plasma pressure (1 torr) inside the reactor; exposure times were 60, 120 and 180 seconds. The modification in dyeability of plasma irradiated yarns was studied by dyeing with three anthraquinone based acid dyes (C.I. Acid Green 25, C.I. Acid Blue 45, and C.I. Acid Blue 80) and measuring dyebath exhaustion and color strength (K/S) of dyed yarns. The improvement in dyeability of plasma irradiated Nomex filament yarn was investigated by studying the surface chemical composition, surface amine concentration, surface topology, and wettability. Surface chemical composition was analyzed by x-ray photoelectron spectroscopy (XPS). The surface amine concentration was evaluated by studying the plasma amination kinetics through ion-exchange reactions between the ionic dye Ponceau Red 3R and Nomex filament yarn. Surface topology of plasma irradiated filament yarns was studied with high resolution scanning electron microscopy (HR-SEM). The wettability of the irradiated Nomex filament yarns was analyzed in terms of grams of deionized water absorbed per gram of fiber after immersing the yarn specimens in de-ionized water for three time periods (15 s, 30 s, 60 s). The effect of irradiation on the filament yarns’ tensile properties was evaluated by measuring breaking tenacity, elongation at break, and toughness. Statistical analyses of data on various parameters included analysis of variance (ANOVA), orthogonal polynomial contrasts between means, and post-hoc Newman-Keuls tests between means. XPS spectra showed a higher concentration of both oxygen and nitrogen atoms at the Nomex filament surface after irradiation. Plasma amination kinetics indicated substantially more primary amino functional groups at the filament yarn surface after the plasma irradiation. SEM photomicrographs of plasma irradiated filament yarn indicated surface etching at low magnification (1,600 X) and surface cavitations at higher magnification (25,000 X). The wettability of irradiated Nomex filament yarns with de-ionized water was significantly higher compared to nonirradiated specimens. The dyeability of ammonia plasma irradiated Nomex filament yarns with acid dyes was improved as indicated by higher dyebath exhaustion and higher color strength. The dyebath exhaustion for the three dyes did not vary noticeably with respect to irradiation times (60 s, 120 s, 180 s). Ammonia plasma treatment adversely affected the tensile properties of Nomex filament yarn to a significant extent only after 180 s. Breaking elongation and toughness were more severely affected after 180 s plasma treatment than was the breaking tenacity. / Ph. D.

This work aims to upcycle old jeans by enhancing both the surface and material as well as generating alternative forms. The work further investigates circumstances, such as gender stereotypes and one garment’s “single” usage. — At its foundation, It initiates by investigating jeans.

Amid growing environmental concern and continuous depletion of natural resources (such as water), the textile industry is constantly searching for sustainable production process. Traditional dyeing processes, notorious for their enormous water consumption, have led society to search alternative dyeing method. Super critical carbon dioxide (scCO2), emerging as a promising dyeing medium shows a potential solution to mitigate water utilization, consequently raising sustainable textile material wet processing. As this innovative technology characterize by its waterless nature, no effluents are generated and conserves enormous amount of water, energy while increasing productivity. Although it has attained commercial focus in polyester fabric dyeing, the imperative remains to reduce energy demand during dyeing process including commercially available dyes. As a result, the optimization of dyeing conditions assumes crucial importance, broadening the feasibility of these eco-friendly dyeing techniques. The objective of this thesis work is to find out the optimum dyeing conditions of polyester (PET) fabric dyeing with an azo disperse dye (Corangar orange PE3330) utilizing supercritical carbon dioxide (scCO2) as a dyeing medium. The investigation aims to unravel the dynamic correlation withing scCO2 dyeing conditions and dye performance. To conduct this study, comprehensive methodology employing a statistical design of two-level three-factor (23) full factorial design was adopted. The studied factors enclose temperature, pressure and dyeing durations, enclosing ranges of 80-1200C, 10-25Mpa and 1-2 hours respectively. Dye concentration was kept constant at 0.2%. The study looks for individual conditions of studied parameters and their impacts on color strength (K/S). Moreover, an analysis of color fastness attributes, comprising washing, sublimation, rubbing and extraction, is carried out. The statistical analysis shows that the prominence of pressure and temperature as the principal factors in scCO2 dyeing medium. Differential scanning calorimetry (DSC) analysis proves the negligible morphological transition in PET fabric following dyeing (crystallinity % for dyed and undyed fabric is 28.80 and 28.42% respectively). Findings also shows that comparable color properties to the traditional standard of PET fabric can be obtained by adapting dyeing pressure (20Mpa) and time (1 hour) while keeping the dyeing temperature (1200C). The findings concluded that satisfactory color strength (K/S) and color fastness related to the standard scCO2 dyeing process can be obtain with reduced energy and pressure. The outcome of this study subtle the relationship between temperature, pressure, and time towards color strength (K/S) and color fastness properties. Nonetheless, investigation of this study remained confined to laboratory-scale and for the purpose to upscale this finding for commercial use, it is crucial to carry out rigorous industrial trials.