Search

The objective of this research was to investigate the effect of cationization on inkjet printing quality. A cotton woven fabric was cationized by pretreatment with 2,3-epoxypropyl-trimethylammonium chloride (EPTAC) using a cold pad-batch method. For the prints, four reactive primary colors (CMYK) were used on both untreated and cationized cotton. The effects of thickener concentration, alkali concentration, and print resolution were investigated. Color yields, outline sharpness, colorimetric properties, fastness properties, staining of the white grounds, and penetration behavior were evaluated. It was found that inkjet printing with reactive dyes on cationized cotton has good potential for providing a cost effective and more environmentally friendly printing method using less dye, less thickener, and less alkali while maintaining high outline sharpness.

Cotton fibers, like most textile fibers, are negative charged (zeta potential) in neutral and alkali aqueous solutions. It is important to consider that dyestuffs, optical brighteners and finishing agents in aqueous solution have the same electrical sign as cotton. In this case difficulties in adsorption processes arise from existing repulsion forces between the particles of the same electrical sign. It is well known that for overcome these forces in dyeing processes, a large amounts of electrolyte is needed, what is economically and ecologically unfavorable. The aim of present paper was to study the cotton modification for achieving its electropositive charge and better dyeing properties. Modification of cotton yarns was carried out with quarternary ammonium compound in different stages of pretreatment for the purpose of lowering the zeta potential of cotton. It is one of alternative method to low the high electrolyte amount in dyeing bath. For this purpose, raw and bleached cotton yarns were cationized with 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride (CHPTAC) before and during the mercerization process. Untreated and mercerized cotton samples are electronegative having the zeta potential, from x = - 15 mV to x= - 20 mV. According to zeta potential results (measured on Electro-kinetic Analyzer-EKA, A. Paar) it was shown that electrical charge of all cationized cotton yarns was noticeable changed, from negative to positive values by 10 to 15 mV. Bleached cationized yarns are electropositive in whole applied pH range (pH 2 to pH 10) while raw cotton yarns are little negative (x = - 5 mV). Such electropositive cottons show the better attracts of electronegative dyestuffs and finishing agents. Breaking force and elongation were measured on Tenso Lab Strength Tester. Although expected the negative mechanical changes, modified cotton showed better properties then untreated one and almost the same properties as well-known positive mechanical changes in mercerization process. Dyeing processes were presumed using direct dyestuff, Tubantin Green GL (Bezema) by an exhaustion method. The samples selected for dyeing were the next: row and bleached cottons separately untreated, mercerized and cationized (before and during the mercerization process). All the yarns were dyed with and without electrolyte (10g/l NaCl), in AHIBA Turbomat (Datacolor) with constant bath flow, in one depth of shade (3% owf), using liquor ration 30:1, at 100 °C, for 90 min. Spectral characteristics were measured on remission spectrophotometer Spectraflash 600 plus-CT (Datacolor). It was shown very high dyeing effect for mercerized and cationized cottons, incomparable with untreated cottons. It is to notice that these cottons dyed in baths without electrolyte content could show better dyeing effects than when electrolyte was added. Electrolyte addition in these cases is unfavorable. Bleached cotton yarns are more hydrophilic than raw ones, so they have stronger reaction with 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride. Due to their hydrophilicity, they have better dye uptake as well. Dyeing effects of mercerized cotton are well known in practice, but cationization during the mercerization process gives a new dimension of cotton pretreatment, as well as the quality assurance of cotton in the future.

In teh wet textile finishing there are many processes dependent on the adsorption properties of textile fibers. It is the first important unit in the application of chemicals on textile materials. it is well known the law adsorption of anionic charged compound on the anionic cotton surface as the consequence of the repulsion of the same charged ion occured in the wet processes. For such reason a large amount of electrolytes is usually needed in the dyebath to overcome this barrier and achieves the sufficient affinity to the cotton. Mercerization increses chemical reactivity of cotton because the hydroxyl groups of cellulose molecules are more accesible. Mercerization additionally results in the changes of negative zeta potential of fiber surface. Regardless of whether mercerizing is done or not the addition of electrolyte in dyeing procedure is needed. This paper is focused on the improved the cotton-anionic compounds interaction by treating the cotton yarns with etoxylated cationic surfactant. The anionic compound applied was anionic charged stylbene derivate fluorescent whitening agents (FWA). For this purpose cotton yarns were mercerized and bleached what was followed by optical bleaching. The mercerization processes were carried in 15 %, 20 % and 24 5 of sodium hydroxide solutions. In the hot rinsing instead of water the solution of short chain etoxylated cationic surfactant was added. The effect of mercerization degree was measured by adsorption of barium hydroxyde expressed as Ba-number. the fluorescence intensity of FWA effect measured using fluorometer and zeta potential of the yarns was measured by streaming current method using Brookhaven-Paar electrokinetic analyzer (EKA) with a cell appropriate for textile fibres.

The analytical distinction of the most common isomeric underivatized hexoses was investigated by means of mass spectrometry experiments. Electrospray ionization and tandem mass spectrometry were used in the analysis of silver and copper-coordinated monosaccharides (D-glucose, D-galactose, D-fructose, O-methyl-α-D-glucose and O-methyl-β-D-glucose). The results show that cationization by Ag+ allows the differentiation of the three first monosaccharides while the complexes formed by association of Cu+ with these three monosacharides display a similar reactivity that prevents stereoisomer distinction. Unlike copper, silver adduct-ions of both α and β anomeric O-methyl-D-glucoses exhibit specific decomposition patterns (i.e. a loss of methanol for the α-anomer and a loss of silver hydride for the β-anomer), which allow an easy characterization. A theoretical survey of selected complexes, based on the use of DFT calculations were carried out on both anomers in order to rationalize the experimental findings.

Selülozik lifler genellikle direkt veya reaktif boyarmaddelerle boyanmaktadır. Bu iki boyarmadde sınıfı selülozik liflerde koyu ve parlak renkler sağlamasına rağmen, genelde life orta bir afiniteye sahiptir. Bu afinite eksikliğinin, geleneksel çektirme yöntemine göre yapılan boyamalarda yüksek miktarda tuz kullanılarak üstesinden gelinmesine rağmen, fikse olmuş boya miktarı düşüktür. Bunun yam sıra selülozik liflerin boyama işlemi fazla miktarda su ve enerji yoğun işlemlerdir ve boyahane atık sularında önemli miktar kimyasal ve boyarmadde kalmaktadır. Anyonik boyaların selülozik liflere afinitesini artırmak için, selülozik liflere katyonik gruplar katılmaktadır. İyonik modifikasyon ile katyonikleşen pamuk, anyonik boyarmaddeler ile daha koyu renkte boyanabilmekte, işlem görmemiş bir pamuklu kumaşın rengini, katyonik pamuk ile tutturabilmek için daha az miktarda boyarmadde gerekmektedir. Bu durum çevrenin korunması açısından da olumlu bir sonuç yaratmaktadır. Bu çalışmada, farklı yöntemler ve kimyasal maddeler denenerek selülozik kumaşların katyonikleştirilmesi olanakları araştırılmış, renk koyulukları ve bazı kullanım özelliklerine etkisi incelenmiştir.Anahtar kelimeler: Selüloz boyamacılığı, direkt boyarmaddeler, reaktif boyarmaddeler, katyonikleştirme, plazma, katyonik pamuk. Cellulosic fibers are usually dyed with direct or reactive dyes. These two dye classes provide cellulosic fibers with complete range of bright and deep colors, but they have only moderate affinity for cellulosic fibers in general. This lack of affinity is overcome in traditional exhaust dyeings by using high level of electrolyte. Furthermore, dye fixation is low. Therefore, the dyeing process of cellulosic fibers is highly water and energy intensive and leaves significant amount of chemicals and color in the dye house effluent, improving the affinity of anionic dyes to cellulosic fibers could be achieved by introducing cationic dye sites to cellulosic fibers. The cotton fibers are basely anionic and they are made cationic by the ionic modification. Thus, the cationic cotton fibers can be dyed by the anionic dyestuffs more deeply. As a result of this characteristics, less dyestuff is needed in order to get the same color of the non-treated cotton fabric by treated cotton fabric. The less need of the dyestuff provides a postive condition for the saving of the environment. In this work, various methods and chemicals were used for the cationization possibilities of cotton fabrics. Various dyeings were made, the color values and some usage properties were observed after dyeings.Keywords: Cellulosics dyeing, direct dyestuffs, reactive dyestuffs, cationizatione, plazma, cationic cotton., 197

ÖZET SAFRANİN-O'NUN YÜZEY AKTİF MADDE MİSELLERİ İLE ETKİLEŞİMİNİN İNCELENMESİ Katyonik bir boyarmadde olan Safranin-O'nun, aynı bidrofob grubu (Lauril) farklı polar grupları içeren anyonik ( Sodyumlaurilsülfat ve Sodyumlaurilsûlfonat ), noniyonik (Tween 20 ve Brij 35), amfoterik ( Laurilsülfobetain ) ve katyonik ( DodesütrimetilamonyumbromÜr ) yüzey aktif maddelerle sulu ortamdaki etkileşimi, yüzey aktif madde derişimine bağlı olarak spektrofotometrik yöntemle çalışıldı. Safranin-O'nun yüzey aktif madde misellerine bağlanma sabitleri ve bağlanma kesirleri, Benesi-Hildebrant Eşitliği ile hesaplandı. Safranin-O'nun misellere bağlanma derecesi ; Tween 20 > Brij 35 > Sodyumlaurilsülfat > Sodyumlaurilsûlfonat > laurilsülfobetain sırasıyla azaldı. Safranin-O'nun anyonik yüzey aktif madde olan Sodyumlaurilsülfat ve Sodyumlaurilsûlfonat ile kritik misel derişimi altındaki derişimlerdeki etkileşimi ayrıca çalışıldı. Job Yöntemi kullanılarak Safranin-0 ile Sodyumlaurilsülfat ve Sodyumlaurilsûlfonat arasında 1:1 moleküler kompleksin oluştuğu ve Sodyumlaurilsülfat ile olan kompleksin oluşum sabitinin Sodyumlaurikütfonatla olandan daha büyük olduğu bulundu. Safranin-O'nun Sodyumlaurilsülfat ve Tween 20 miselleriyle etkÜeşimine değişik yüzdelerdeki organik çözücülerin; MetanoL, Dimetilformamid ve Dioksan etkisi araştırıldı. Ortamda organik çözücü derişimi arttıkça, misel boyutu küçüldü, Safranin-O'nun miselle etkileşme derecesi azaldı ve aynı derişimdeki çözücünün bağlanmayı azaltma etkisi ; Dioksan > Dimetilformamid > Metanol sırasını izledi Safranin-O'nun kritik misel derişimi altındaki derişimlerdeki Sodyumlaurilsülfatla etkileşimine organik çözücü etkisi araştırıldı. Moleküler kompleks oluşumuna organik çözücü etkisinin, misele bağlanmaya olan etkisiyle aynı sırayı izlediği bulundu. XXI SUMMARY STUDIES ÖN THE INTERACTION OF SAFRANIN-O WITH SURFACTANT MICELLES The interaction of Safranin-0, a cationic dye, with various surfactants, having the same hydrophobic group ( Lauryl ) and different polar groups, as anionic ( Sodhimlaurylsulfate and Sodiumlaurylsulfonate ), nonionic ( Tween 20 and Brij 35), amphoteric ( Laurylsulfobetaine) and cationic ( Dodecyltrimethylammonhim Bromide ), in aqueous media was studied by spectrophotometric method as a function of surfactant concentration. The binding constants and fraction of bound Safranin-0 to micelles were calculated by means of Benesi-Hildebrand Equation. The binding degree of Safranin-O to micelles has been found to follow the order : Tween 20 > Brij 35 > Sodiumlaurilsulfate > Sodiumlaurilsulfonate > Laurilsulfobetaine. The interaction between Safranin-0 and anionic surfactants Sodiumlaurylsulfkte and Sodiumlaurylsulfonate at concentrations below their critical micelle concentrations was studied separately. The results obtained with Job's Method indicated the formation of 1:1 molecular complex between Safranin-O and anionic surfactants ( Sodiumlaurylsulfate and Sodiumlaurylsulfonate ). The complex formation constant with Sodiumlaurylsulfate was found to be higher than the one formed with Sodiumlaurylsulfonate. The effect of organic solvents as, Methanol, Dimethylformamide and Dioxan at various percentages, on the interaction of Safranin-0 to micelles of Sodiumlaurylsulfate and Tween 20 was studied. As the concentration of organic solvents increased, the micellar size and interaction degree between Safranin-0 and micelles decreased and this effect of solvents followed the order: Dioxan > Dimethylformamide > Methanol. Influence of organic solvents on the interaction of Safranin-0 with Sodiumlaurylsulfate at the concentration below the critical micelle concentration was studied. The order of the influence of organic solvents on the formation of molecular complex was found to be the same as their influence on binding to micelles. XXII 245

(Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2001, (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2001, Bu çalışmada pamuklu materyallerin boyanabilirliği, kolay bakım özellikleri olarak ifade edilen buruşmazlık ve boyut stabilitesi araştırılmıştır. Katyonikleştirme maddesi olarak kullanılan choline klorür, köprü bağı oluşturucu olarak kullanılan buruşmazlık apre maddesi vasıtasıyla selüloza bağlanmaktadır. Katyonikleştirme işleminde mukavemet değerlerinde görülen düşmeler nedeniyle klasik emdirme-kurutma-kondenzasyon yerine emdirme-buharlama-kondenzasyon işlemi uygulanmıştır. Katyonikleştirme işlemi görmüş numuneler bir yün boyarmaddesi olan asit boyarmaddeleri ile boyanabilmelerinin yanında reaktif ve substantif (direkt) boyarmaddeleriyle, değişik boyama metodlarına göre boyanmıştır. Katyonik pamuğun farklı ve çapraz boyama metodlarına uygunluğu saptanmıştır. Katyonikleştirme işlemi, pamuk kumaşın boyanabilirliğini arttırırken, kolay bakım özellikleri olan boyutsal stabilite ve buruşmazlık derecesinde artışlar yarattığı saptanmıştır. Merserizeli ve merserizesiz pamuk kumaşlar bu çalışmada kullanılmıştır., In this study the dyeability and smooth-dry performance properties such as recovery angle and dimensional stability of cotton fabric were investigated. Determination of the effect of cationic modification of the cotton was the primary objective. Choline chloride was used as the cationic agent and it was bounded to the cellulose with a crosslinking agent. In the cationisation process a non-conventional pad-steam-cure application method was used and this was compared with a conventional pad-dry-cure method. The pad-steam-cure method did not reduce the mechanical properties of the cotton to the same extent as the traditional process.The cationised cotton was dyeable with acid dystuffs of the type suitable for wool in addition to reactive and direct dyes. Suitable different dyeing procedures were used for each dyestuff type. It is concluded that cationic modified cotton is suitable for differential dyeing and cross-dyeing applications. It is determined that cationization process both enhanced its dyeability and increased its smooth-dry performance properties such as dimensional stability and recovery angle. Both mercerized and unmercerized cotton fabrics were used on this study., Doktora, PhD

The analytical potential of the complexation of three isomeric monosaccharides (D-glucose, D-galactose, D-fructose)and two methyl glycosides ( O-methyl-α-D-glucose and O-methyl-β-D-glucose)by three metal ions, Ag+, Cu+ and Pb2+, has been investigated by fast-atom bombardment (FAB)ionization and tandem mass spectrometry. Our results have shown that the unimolecular reactivity of Ag+ complexes allows the characterization of the C(4)stereochemistry of the pyranose ring, whereas a distinction between D-glucose and D-fructose is not achieved. On the other hand, each of the three [Cu + monosaccharide]+ complexes exhibits specific dissociation patterns. We have also observed that Pb2+ ions induce the richest reactivity and are of particular interest for the identification of the three isomers. Finally, this study has demonstrated that the stereochemistry of the anomeric center of O-methyl-D-glucose is easily determined by reaction with Ag+ or Pb2+ ions. Several mechanisms are proposed to account for the main fragmentations of cationized glucose.

International audience; Tetanus neurotoxin reaches the CNS by axonal retrograde transport and thus becomes inaccessible to current treatments. A possible strategy to improve current therapy for tetanus disease would be the vectorization of Fab'2 fragments, allowing their delivery into the CNS. The purpose of this study was to investigate whether after cationization anti-tetanus Fab'2 fragments are able to cross the blood–brain barrier, the first obstacle to CNS delivery. We used primary cocultures of bovine brain capillary endothelial cells and newborn rat astrocytes as an in vitro model to study the binding and transport of cationized Fab'2 (cFab'2) fragments across the brain endothelium. We first show that cationization does not alter Fab'2 affinity for tetanus toxin. Then we demonstrate that after cationization Fab'2 fragments are able to bind to the negative charges on the surface of endothelial cells and subsequently to be transported across the endothelial cell monolayer without any modification of affinity. Finally, using fluorescence microscopy, we show that cFab'2 fragments are transported through endocytotic vesicles. The present study demonstrates that cationization allows Fab'2 directed against tetanus toxin to be transported through brain endothelium by adsorptive-mediated transcytosis. We suggest that this vectorization way could be a promising delivery strategy for carrying anti-tetanic immunoglobulin fragments across the blood–brain barrier to improve tetanus treatment.

Interface phenomena have a significant role in wet finishing processes of cotton. Therefore, interface phenomena of cotton fabric, cationized with commercial cationic compound, were studied in this paper. The characterization of surface after cationization, was performed by FTIR-ATR and SEM. Interface phenomena were studied through electrokinetic phenomena, surface free energy and adsorption. Zeta potential, Isoelectric point (IEP) and Point of zero charge (PZC) were determined according to streaming current/streaming potential method ; specific amount of surface charge and adsorption of a ionic surfactant by potentiometric titration method ; surface free energy by thin layer wicking method. The affinity of such modified cotton for reactive dyes having different functional groups was investigated through the K/S values. The effect of electrolyte addition on dye bath was investigated as well.

Interface phenomena have a significant role in the wet finishing processes. Therefore in this paper the electrokinetic phenomena of cotton fabric cationised with a commercial cationic compound were researched. After cationisation, characterisation of the surface and chemical composition was performed by FTIR-ATR. Electokinetic phenomena - Zeta potential, Isoelectric point (IEP) and Point of zero charge (PZC), were determined according to the streaming current/streaming potential method and a specific amount of surface charge according to the back-titration method. The affinity of such modified cotton to reactive dyestuff of different functional groups was investigated through the K/S values. The influence of electrolyte addition to the dye bath was investigated as well.