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1 – 4 of 4Junling Wu, Longfei Sun and Long Lin
This study aims to dye silk with natural pigments extract of Coreopsis tinctoria, by treating the fabrics with appropriate mordant under suitable dyeing conditions, to achieve…
Abstract
Purpose
This study aims to dye silk with natural pigments extract of Coreopsis tinctoria, by treating the fabrics with appropriate mordant under suitable dyeing conditions, to achieve good dyeing depth, fastness and ultraviolet (UV) protection.
Design/methodology/approach
Firstly, single factor experiments were used to determine the basic dyeing conditions of Coreopsis tinctoria. The optimal process conditions for direct dyeing were determined through orthogonal experiments. After that, the dyeing with mordant was used. Based on the previously determined optimal process conditions, silk fabrics were dyed with different mordanting methods, with different mordants and mordant dosages. The dyeing results were compared, in terms of the K/S values of the dyed fabrics, to determine the most appropriate dyeing conditions with mordant.
Findings
The extract of Coreopsis tinctoria can dye silk fabrics satisfactorily. Good dyeing depth and fastness can be obtained by using suitable dyeing methods and dyeing conditions, especially when using the natural mordant pomegranate rind and the rare earth mordant neodymium oxide. The silk fabrics dyed with Coreopsis tinctoria have good UV resistance, which allows a desirable finishing effect to be achieved while dyeing, using a safe and environmentally friendly method.
Research limitations/implications
The composition of Coreopsis tinctoria is complex, and the specific composition of colouring the silk fibre has not been determined. There are many factors that affect the dyeing experiment, which have an impact on the experimental results.
Practical implications
The results of this study may help expand the application of Coreopsis tinctoria beyond medicine.
Originality/value
To the best of the authors’ knowledge, this paper is the first report on dyeing silk with the extract of Coreopsis tinctoria achieving good dyeing results. Its depth of staining and staining fastness were satisfactory. Optimum dyeing method and dyeing conditions have been identified. The fabric dyed with Coreopsis tinctoria has good UV protection effect, which is conducive to improving the application value of the dyeing fabric. The findings help offer a new direction for the application of medicinal plants in the eco-friendly dyeing of silk.
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Kathirvel Kalaiselvi, Ill-Min Chung, Seung-Hyun Kim and Mayakrishnan Prabakaran
The purpose of this paper is to investigate the inhibitive performance of Coreopsis tinctoria (C. tinctoria) plant extract for the corrosion of mild steel in 0.5 M H2SO4.
Abstract
Purpose
The purpose of this paper is to investigate the inhibitive performance of Coreopsis tinctoria (C. tinctoria) plant extract for the corrosion of mild steel in 0.5 M H2SO4.
Design/methodology/approach
The inhibition efficiency was studied by weight loss, electrochemical measurements and the surface analysis was done by Raman, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) and atomic absorption spectroscopy (AAS) analysis.
Findings
Maximum inhibition efficiency of C. tinctoria in 0.5 M H2SO4 on mild steel is 80.62 per cent (500 ppm) at 303 ± 1K. The adsorption of the C. tinctoria on the mild steel surface in 0.5 M H2SO4 was found to obey Langmuir adsorption isotherm. Temperature studies were carried out and the significant parameters, such as change in enthalpy (ΔH°), change in entropy (ΔS°) and change in free energy (ΔG°ads) and heat of adsorption (Qads), were calculated. The productive layer formed on the mild steel surface in 0.5 M H2SO4 were confirmed by the Raman spectral analysis.
Originality/value
This paper provides information on the inhibitive properties of C. tinctoria plant extract which is found to be a good corrosion inhibitor for mild steel in 0.5 M H2SO4.
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Shamnamol G.K., Sam John and Jaya Mary Jacob
Surface pretreatment of iron and its alloys to remove stains and inorganic contaminants on the metal surface undergoes dissolution by virtue of the strong acidic media thereby…
Abstract
Purpose
Surface pretreatment of iron and its alloys to remove stains and inorganic contaminants on the metal surface undergoes dissolution by virtue of the strong acidic media thereby increasing its susceptibility to corrosion. The purpose of this study is to explore the corrosion mitigation prospects of green corrosion inhibitors on mild steel surface.
Design/methodology/approach
Corrosion inhibition performance of Garcinia gummi-gutta leaf extract (GGLE) was explored against mild steel in 1 M HCl solution using the weight-loss method, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. Surface characterization was carried out to study the mechanism of inhibitor action.
Findings
The concentration of GGLE varied from 100 to 6,000 ppm and the result indicates that corrosion inhibition efficiency was amplified by raising the inhibitor concentration. The maximum inhibition efficiency was 82.2% at 6,000 ppm concentration. EIS results show the development of a protective layer of inhibitor molecule over the metal surface and PDP demonstrates that the inhibitor operates as a mixed-type inhibitor. Scanning electron microscopy and atomic force microscopy were executed to assess the surface morphology and roughness, respectively.
Originality/value
To the best of the authors’ knowledge, so far, no studies have been reported on the corrosion inhibition performance of GGLE which is rich in many bioactive components especially hydroxyl citric acid. This work encompasses the corrosion inhibition capability of GGLE against mild steel in an acidic medium.
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Swetha Andra, Murugesan Muthalagu, Jaison Jeevanandam, Durga Devi Sekar and Rajalakshmi Ramamoorthy
A widespread focus on the plant-based antimicrobial cotton fabric finishes has been accomplished with notable importance in recent times. The antimicrobials prevent microbial…
Abstract
Purpose
A widespread focus on the plant-based antimicrobial cotton fabric finishes has been accomplished with notable importance in recent times. The antimicrobials prevent microbial dwelling in fabrics, which causes severe infections to the fabric users. Chemical disinfectants were conventionally used in fabrics to address this challenge; however, they were found to be toxic to humans. Thus, the present study aims to deal with the utilization of phytochemical extracts from different parts of Pongamia pinnata as antimicrobial coatings in cotton fabrics.
Design/methodology/approach
The root, bark and stem were collected and washed several times using tap water. Then, the leaves were dried at room temperature and the root and bark were dried using an oven at 40ºC. After drying, they were ground into fine powder and extracted with ethanol using the Soxhlet apparatus. After that the extract was coated on the fabric tested for antimicrobial studies.
Findings
The results reported that the leaf extract of P. pinnata-coated fabric exhibited enhanced antibacterial property towards gram-negative Escherichia coli bacteria, followed by root, bark and stem. The wash durability test in the extract-coated fabric samples revealed that dip-coating retained antibacterial activity until five washes. Thus, the current study clearly suggests that the leaf extract from P. pinnata is highly useful to develop antibacterial cotton fabrics as health-care textiles.
Originality/value
The novelty of the present work is to obtain the crude extract from the leaves, bark, root and stem of P. pinnata and evaluate their antibacterial activity against E. coli, upon being coated on cotton fibres. In addition, the extracts were subjected to wash durability analysis to study the coating efficiency of the phytochemicals in cotton fabrics and a probable mechanism for the antibacterial activity of P. pinnata extracts was also presented.
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