Eco-Friendly Procedure for Rendering the Antibacterial and Antioxidant of Cotton Fabrics via Phyto-Synthesized AgNPs With Malva sylvestris (MS) Natural Colorant

There is a growing interest for producing multifunctional cellulose fabrics using green and sustainable technology. In this study, we explored an eco-friendly procedure for dyeing cotton fabrics with Malva sylvestris (MS) as a natural colorant and rendering antibacterial cotton fabric by the silver nanoparticles. MS colorants were extracted from dried petals in water using the ultrasound technique, cotton fabrics were dyed with the extracted MS colorant at 100°C for 90 min. The colorimetric data and colorfastness properties were investigated in the absence and presence of tannic acid (TA) as a bio-mordant. Results indicated that MS dye had a high potential for reducing the silver nitrate, so that the silver particle size distribution on cotton fabric was obtained 50–80 nm, and TA had a positive effect on the MS extract and reduced Ag on the cotton. Furthermore, the reduction of bacterial growth of the dyed cotton considerably (up to 99%) improved by AgNPs. The wash-, and light-fastness properties of samples dyed with MS were enhanced from moderate to good-very good by mordanting.

Investigating the Possibility of Determining the Sequence Intersecting Lines between LaserJet Printing and Handwriting in Document Examination using Color Measurement Technique

In Questioned Documents Examination, the sequence of crossing lines in the intersection of handwriting and printed area can be important clues for detecting tampered documents. Recognition of such documents is a arduous task and requires people with experience and expertise. In the present work, we investigated the possibility of determining the sequence of intersecting lines between LaserJet printing and handwriting for a series of simulated laboratory specimens in the document examination using color measurement technique. The spectral reflectance curves and color coordinates of some points on and out of the cross lines were compared. Four different commercial ballpoint pens and a black toner LaserJet were used to prepare the specimens. The color change of the intersecting lines was subjectively considered through the captured images and a visual assessment process. It was also objectively determined by determining the color difference values from the colorimetric data in CIELAB and CIELCH color spaces in the visible range. The color change evaluation showed that the order in which printing or handwriting is applied alters colorimetric results. Moreover, the investigations showed small color difference values of less than 2 units between a point of printed area individually, and intersection could be applied as a tolerance limit for pass/fail judgments.

Methods to improve colour mismatch between displays

With the rapid development of display technology, the colour mismatch of the colours having same tristimulus values between devices is an urgent problem to be solved. This is related to the wellknown problem of observer metamerism, caused by the spectral power distribution (SPD) of primaries and the difference between individual observers' and the standard CIE colour matching functions. An experiment was carried out for 20 observers to perform colour matching of colour stimuli with a field-of-view of 4° between 5 displays, including two LCD and two OLED, against a reference LCD display. The results were used to derive a matrixbased colour correction method. The method was derived from colorimetric visually matched colorimetric data. Furthermore, different colour matching functions were evaluated to predict the degree of observer metamerism. The results showed that the correction method gave satisfactory results. Finally, it was found that the use of 2006 2° colour matching function outperformed 1931 2° CMFs with a large margin, most marked between an OLED and an LCD display.

Predicting Camera Color Quality

Color quality can be measured two ways. The first is target based where color-difference statistics are reported comparing image data with measurement-based colorimetric data. The second is based on measuring the camera sensor’s spectral sensitivities and calculating their similarity to a standard observer, for example, μ-factor. A computational experiment was performed where synthetic images of a variety of targets were rendered for four camera systems having μ-factors of 0.79, 0.88, 0.94, and 0.99. Each camera was profiled using the same target. Although profile color accuracy was acceptable for all the cameras, this did not predict the color accuracy for independent targets. μ-factor was a better predictor of color quality and its use is recommended when evaluating cameras for cultural heritage applications

Spectral Imaging Method for Transmissive Media

An imaging process is described which captures spectral transmittance for transmissive media. The specific application is positive and negative large-format film. The system is based on a ten channel LED backlight source and a monochrome camera. The LED source sequentially back-illuminated reference targets and film samples, with an image captured for each LED channel. From the measured data and images of reference targets, a model was developed to predict spectral transmittance. With that model, the 10 images of a sample were combined to a single 31-band spectral image. Spectral images can be used to calculate colorimetric data for each pixel. These colorimetric results show that the system produces good colorimetric predictions when compared to the most relevant FADGI guidelines. Some improvement is required for the spectral model particularly in the red region.

New class of magenta dyestuffs based on azomethine pyrazolone disperse dyes: Synthesis, characterization, and dyeing performance on polyester fabrics with ultraviolet protection and pH-dependent properties

Eight azomethine pyrazolone magenta dyes with iminodiethanol groups have been synthesized from 1,3-disubstituted- 1H-pyrazol-5( 4H)-ones in good yield. The newly synthesized dyes were characterized using spectroscopic data and elemental analyses techniques. All dyes have been successfully applied to polyester fabrics as disperse dyes where their dyeing performances have been discussed and evaluated in detail. The shades of these dyes ranged from red violet, purple and dark purple colors with good depth, brightness and good leveling properties. Multifunctional properties such as color representation, colorimetric data (L*, a*, b*, C*, h*, K/S), fastness properties of the dyed samples with respect to washing, perspiration, rubbing and light fastness have been discussed and evaluated in detail. The degree of exhaustion and fixation was also achieved after establishing the optimal dyeing conditions at 130°C, high pressure, 2% shade, and pH ≈5. As well, the influence of the dye bath pH on the K/S percentage and color intensity was estimated and discussed. Furthermore, the dyed fabrics were tested for ultraviolet protection factor and the results showed that these dyes gave excellent ultraviolet protection.

A study on the applicability of pigment digital printing on cotton fabrics

In digital printing, the fabric print quality can only be evaluated through the color and pattern of printed fabric after printing. The influence of the physical properties of fabric on the printing effect remains unclear. In this paper, the digital print suitability of cotton fabric was defined, and 14 samples of plain cotton fabrics were taken as research objects. In addition, 11 evaluation indexes of cotton fabrics were selected. The evaluation and prediction model of cotton fabric printability was established by principal component analysis. Furthermore, the prediction results of the model were verified by analyzing the colorimetric data of cotton fabric after printing. The result demonstrated that the evaluation model of printing suitability was applicable and can be used to quickly evaluate the printability of cotton fabrics. Particularly, fabric thickness had the greatest influence on printing permeability. In the case of moderate wicking, the higher the whiteness of cotton fabric, the better the color reproducibility after printing. Additionally, the wicking effect also had a great influence on color performance.

Preparation of Chitosan Nanoparticles and its Utilization as Novel Powerful Enhancer for Both Dyeing Properties and Antimicrobial Activity of Cotton Fabrics

Replacement of conventional chemicals with modern fewer hazards one has great attention via green chemistry. Chitosan nanoparticles (CSNPs) were prepared from the reaction of chitosan (0.2 g/100 ml) with tripolyphosphate (o.1 g/100 ml) through the ionotropic gelation method. CSNPs with different concentrations were used for cotton fabrics to impart antimicrobial activity and enhance their dyeing affinity towards acid dyes. FT-IR spectroscopy and TEM imaging were used to characterized CSNPs. SEM and TGA. Effect of CSNPs concentrations on cotton fabric dyeing affinity was recorded from colorimetric data. The antimicrobial activity of treated dyed fabrics was evaluated via disk diffusion method against S. aureus, E. coli, Candida, and Aspergillus Niger. Results have shown that cotton fabrics treated with 0.3 g/100 ml record the highest K/S values, Corresponding to the highest dyeing affinity towards acid dyes. In addition, treated dyed cotton fabrics were showed higher antimicrobial activity towards tested microorganisms because of the presence of CSNPs. Morphological studies on the untreated, treated, and treated dyed cotton fabrics via SEM imaging confirmed that CSNPs coated cotton fabrics. In addition, the light and washing fastness properties of these fabrics confirmed their durability. Therefore, CSNPs were used to impart cotton fabrics' antibacterial activity and improve their dyeability with acid dye.

Use of quantitative colorimetry and visual evaluation for color characterization of triticale seeds after phenol reaction

Quantitative colorimetry can be used to characterize the color of triticale seeds submitted to the phenol test. This study aimed to characterize the color of triticale seeds after the phenol test by visual color evaluation and quantitative colorimetry using the CIELAB color space. The evaluated seeds came from 88 triticale genotypes from the IDR-Paraná Germplasm Bank. The colorimetric data for L (lightness) and chromaticity coordinates a* and b* of the seeds before and after phenol reaction were obtained using a Minolta CR-400 colorimeter. The score scale ranged from 1 (very weak or absent color) to 9 (very dark color) and evaluated visually the seed color after phenol reaction. Seeds classified as score 1 showed mean values of 46.3, 6.6, and 16.4 for L, a*, and b*, respectively. On the other hand, seeds classified as dark or very dark showed values equal to or lower than 28.4 for L, 5.6 for chromaticity a*, and 6.0 for chromaticity b*. The use of colorimetric parameters showed a practical application and low subjectivity in the classification of the color of triticale seeds after phenol reaction.

Biopolymer-Based Hybrids as Effective Admixtures for Cement Composites

In the framework of this publication, silica-lignin hybrid materials were designed, obtained, characterized and then used as admixtures for cement composites. High-energy mechanical grinding of individual components was used to produce the systems that allowed ensuring adequate homogeneity of the final products. As a result of the analysis of Fourier transform infrared spectroscopy, it has been confirmed that weak physical interactions occur between the components. This allowed classifying the resulting systems as I class hybrid materials. In addition, the efficiency of obtaining final products was also inferred on the basis of obtained porous structure parameters and colorimetric data. The achieved bio-admixture with different weight ratios of silica and lignin was added to cement pastes in the amount ranging from 0.5 to 1 wt.%. The study showed that increasing the ratio of lignin in the admixture from 0.15 to 1 wt.% had a positive effect on the rheological properties of the pastes, while the mechanical properties of the composite were deteriorated. In turn, a higher amount of silica in the admixture acted in reverse. The most favorable results were obtained for a silica-lignin bio-admixture with a weight ratio of components equal to 5:1 wt./wt. A significant increase in compressive strength was gained at satisfactory plasticity of the paste.