Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Recent advancements in natural dye applications: a review

Perspectives for natural product based agents derived from industrial plants in textile applications – a review

Dyes derived from natural materials such as plant leaves, roots, bark, insect secretions, and minerals were the only dyes available to mankind for the coloring of textiles until the discovery of the first synthetic dye in 1856. Rapid research strides in synthetic chemistry supported by the industrialization of textile production not only led to the development of synthetic alternatives to popular natural dyes but also to a number of synthetic dyes in various hues and colors that gradually pushed the natural dyes into oblivion However, environmental issues in the production and application of synthetic dyes once again revived consumer interest in natural dyes during the last decades of the twentieth century. Textiles colored with natural dyes are preferred by environmentally conscious consumers and today there is a niche market for such textiles. But the total share of natural dyes in the textile sector is approximately only 1 % due to certain technical and sustainability issues involved in the production and application of these dyes such as nonavailability in ready-to-use standard form, unsuitability for machine use, and limited and nonreproducible shades. Natural dyes per se are sustainable as they are renewable and biodegradable but they cannot fulfill the huge demand from the textile sector in view of the preferential use of land for food and feed purposes. Also, overexploitation of natural resources to obtain dyes may result in deforestation and threaten endangered species. For these reasons, the Global Organic Textiles Standard (GOTS) permits the use of safe synthetic dyes and prohibits the use of natural dyes from endangered species. Various research efforts have been undertaken all over the world to address the shortcomings of natural dyes in view of the tremendous environmental advantage they offer. This book attempts to review the current status of natural dyes and various sustainability issues involved in their production and application and examines their future prospects.

Natural Dyes: Sources, Chemistry, Application and Sustainability Issues

Color is a major attraction component of any fabric regardless of how admirable its constitution. Industrial production and utilization of synthetic dyestuffs for textile dyeing have consequently become a gigantic industry today. Synthetic dyestuffs have introduced a broad range of colorfastness and bright hues. Nonetheless, their toxic character has become a reason of serious concern to the environment. Usage of synthetic dyestuffs has adverse impacts on all forms of life. Existence of naphthol, vat dyestuffs, nitrates, acetic acid, soaping chemicals, enzymatic substrates, chromium-based materials, and heavy metals as well as other dyeing auxiliaries, makes the textile dyeing water effluent extremely toxic. Other hazardous chemicals include formaldehyde-based color fixing auxiliaries, chlorine-based stain removers, hydrocarbon-based softeners, and other non-biodegradable dyeing auxiliaries. The colloidal material existing alongside commercial colorants and oily froth raises the turbidity resulting in bad appearance and unpleasant odor of water. Furthermore, such turbidity will block the diffusion of sunlight required for the process of photosynthesis which in turn is interfering with marine life. This effluent may also result in clogging the pores of the soil leading to loss of soil productivity. Therefore, it has been critical for innovations, environmentally friendly remediation technologies, and alternative eco-systems to be explored for textile dyeing industry. Different eco-systems have been explored such as biocolors, natural mordants, and supercritical carbon-dioxide assisted waterless dyeing. Herein, we explore the different types of dyeing processes, water consumption, pollution, treatment, and exploration of eco-systems in textile dyeing industry.

Textile dyeing industry: environmental impacts and remediation

Eco-dyeing using Tamarindus indica L. seed coat tannin as a natural mordant for textiles with antibacterial activity

Natural dyes, which were pushed during the last sixty years into the background by synthetic dyes, are recently again becoming object of consumer interests. This is due to the awareness of possible risks during production of synthetic dyes which involve use of petrochemical based raw materials and the violent chemical reactions for their synthesis. The manufacture of such dyes is energy intensive with adverse impact on environment adding to its pollution. Many of these dyes, especially the azo- based ones, are found to be carcinogenic. In this background, a brief review of natural colourant from plant sources, their classification, chemical constituents responsible for producing different colours, its activities and effect of different mordants on the hue is discussed. Different classes of mordants employed for fixation of natural colouration on textiles substrated, its mechanism and plant sources are also discussed.

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Plant based natural dyes and mordnats: A Review

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.

Eco-Friendly Dyeing Using Natural Mordant Extracted from Emblica officinalis G. Fruit on Cotton and Silk Fabrics with Antibacterial Activity

In the present investigation, γ-acid was reacted first with acid chloride namely pentadecafluoro octanoyl chloride, which was synthesized by the reaction with thionyl chloride and pentadecafluoro octaconic acid. The resulting compound was coupled with m-toluidine and thus dye 1F1 of reddish pink hue was synthesized. Similarly in place of m-toluidine, m-trifluromethyl aniline was used with the same intermediate and dye 1F2 with brighter reddish pink was obtained. In case of 2F1 and 2F2 dyes synthesized only the γ-acid in 1F1 and 1F2 was replaced by H-acid. These dyes are brown in shade. The water repellency effect of a long chain derivative containing perfluoro group on the fabric dyed with the synthesized modified monoazo acid dyes was studied.

http://www.asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=20_6_12

K. H. Prabhu

Papers

Eco-dyeing using Tamarindus indica L. seed coat tannin as a natural mordant for textiles with antibacterial activity

Plant based natural dyes and mordnats: A Review

Eco-Friendly Dyeing Using Natural Mordant Extracted from Emblica officinalis G. Fruit on Cotton and Silk Fabrics with Antibacterial Activity

Synthesis and Application of Monoazo Acid Dyes Containing Long Chain Perfluoroalkyl Group for Water Repellant Polyamides