Blue Ink Research Articles

Cost-effective Skin Marking in Joint Replacement Surgery: A Comparative Study between Methylene Blue Ink and Commercially Available Skin Markers.

This study aimed to assess and compare the effectiveness and safety of methylene blue ink and commercially available surgical marker pens in pre-operative skin marking for joint replacement procedures. The objective was to evaluate the visibility of the surgical instruments during the operation and their influence on the occurrence of infections after the surgery, providing valuable information on the practical use and cost-effectiveness. This retrospective randomized study involved 150 total cases, which included knee replacements, total hip replacements, and hip hemiarthroplasty performed between 2020 and 2023. The same surgeon conducted all procedures, and the patients were randomly assigned to two groups: One marked with methylene blue ink and the other with a commercially available sterile marker pen. Limb preparation followed an identical protocol for both groups. The primary outcomes assessed were the visibility of markings at the end of the procedure and the incidence of post-operative infections. The visibility of markings was satisfactory in both groups, with the methylene blue group displaying more pronounced visibility. Importantly, there were no cases of post-operative infections or permanent tattooing attributed to either marking method. This study demonstrates that both methylene blue ink and commercially available surgical marker pens provide effective skin markings for surgical procedures without increasing the risk of post-operative infections or causing permanent tattooing. Methylene blue ink showed more evident marking post-procedure and ink form remains a cheaper alternative.

Extraction of Dye from Waste Blue Gel Pen Ink Using the Voltine Method and Its Application in Fabric Dyeing: An Eco-friendly Approach

Extraction of Dye from Waste Blue Gel Pen Ink Using the Voltine Method and Its Application in Fabric Dyeing: An Eco-friendly Approach

Digital color analysis and machine learning for ballpoint pen ink clustering and aging investigation

Fraudulent activities often involve document manipulation, which poses a significant challenge to forensic science. To address this issue, a novel method was developed that combines intended artificial UV pre-degradation, digital color analysis (DCA) of stroke images, and various machine learning (ML) models. This method can cluster blue ballpoint pen inks and predict their photodegradation time. The results of the study indicate that the k-shape clustering method is highly effective in differentiating between inks based on their degradation curve patterns and HSV or RBS color features, aligning well with results from chromatography analyses. Furthermore, the random forest regression model demonstrated superior performance in predicting age, exhibiting the highest coefficients of determination. The DCA-ML method is a straightforward, cost-effective, and highly accurate solution for clustering blue pen inks. Using photodegradation curves to predict document age could eliminate the need for conventional physicochemical analysis techniques.

From color naming to color perception: Cross‐linguistic differences of the chromatic information processing in monolingual and bilingual speakers

AbstractThere has been long running debate about the interaction of language and perception. In this context, bilingual people have often shown benefits, due to their double‐active linguistic system, in cognitive functions, like inhibition, attention, and memory, which are central for visual perception. Color naming and categorization are domains for studying cross‐linguistic effects, which arise from conceptual and perceptual variations across speakers of different languages. In this study, we compared the ‘blue’ lexicon of highly proficient French‐Italian bilinguals to monolingual speakers of the corresponding languages. Prior studies have shown that Italian has two basic color terms for the blue area of color space: one denotes light blue hues (azzurro) and the other dark blue hues (blu), whilst French, with only one basic term bleu, lacks this distinction. We used a Stroop test to probe differences in perception and categorization of blue in bi‐ and monolingual speakers. We found that Italian monolinguals name the ink color more accurately and more rapidly when the word blu is rendered in dark blue ink (corresponding to the word blu) than when it is printed in light blue ink (corresponding to azzurro), since the latter represents an incongruent condition for them. This ‘category effect’ does not exist for French monolingual speakers. Our bilinguals' results demonstrate that, despite the emergence of a specific in‐between perceptual behavior, bilinguals generally performed like Italian monolinguals. These outcomes confirm the hypothesis that their second language categories (Italian) dominate their native language (French), attesting that lexical distinctions influence perceptual faculties in general. However, the ratio of the interference effect (longer reaction times for incongruent stimuli compared to control stimuli) and the facilitation effect (shorter reaction times for congruent stimuli compared to control stimuli) is not the same for bilinguals and monolinguals. The highest magnitude in the facilitation effect was revealed for bilinguals, whereas the highest magnitude in the interference effect was revealed for Italian monolingual speakers. This phenomenon adds evidence to the existence of enhanced bilingual cognitive control abilities.

Blue light excitable fluorescent green security ink for anticounterfeit application

AbstractFluorescent security printing inks on flexible substrates is an arena that demands consistent developments to prevent the ever increasing menace of document/product counterfeiting. Visible light is a much more accessible and safer excitation source than the commonly used ultraviolet (UV) light. In this context, a simple Schiff base 4-pyridyl-benzylidene 2,4-difluoro aniline (PBDFA) is synthesized as a colorant with significant solid-state fluorescence for preparing security ink formulation. A huge challenge lies in preparing a security ink that does not fluoresce under UV light but produces a green fluorescence when irradiated with a blue light source. Such prints would be hard to forge as compared to the existing UV luminescent security inks. The screen prints obtained on a UV dull paper substrate using the solvent-based PBDFA ink revealed good blue light excitable green fluorescence, photostability, and colorimetric, densitometric, and rub resistance characteristics.

Forensic differentiation of blue pen inks using time-of-flight secondary ion mass spectrometry and multivariate statistical methods

This study investigates the use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with multivariate statistical analysis for the identification of blue pen strokes in document forgery cases. Strokes of six commercially available blue pens were analysed using ToF-SIMS, and the data were interpreted using principal component analysis (PCA) and multivariate curve resolution (MCR). PCA effectively reduced the dimensionality of the complex ToF-SIMS data, enabling clear differentiation of the blue pen inks based on the obtained PCA scores. The first three principal components accounted for most of the variance, with PCA score plots showing distinct clusters of samples corresponding to the spectra of each pen. PCA analysis of the large-area ToF-SIMS images further revealed some characteristic spatial patterns and variations across the pen strokes; however, this analysis was less useful for the identification process. On the other hand, MCR provided a more chemically intuitive analysis by extracting pure component spectra from the complex mixtures. Each MCR factor was individually associated with a specific pen, allowing for exact identification of the pen stroke made. MCR score images displayed clear correlations with individual pen strokes, and the associated loadings identified signals at particular m/z values that were characteristic of each pen. This study shows that an efficient method for non-destructive forensic analysis of blue pen strokes can be achieved by combining ToF-SIMS with PCA and MCR. This analytical method provides reliable identification, which is crucial for forgery detection without requiring any sample pretreatment, i.e. the samples (pen strokes) were used just as they were made on paper.

Surface Modification of Silk Fabric by Polysaccharide Derivatives towards High-Quality Printing Performance Using Bio-Based Gardenia Blue Ink.

Ink-jet-printed silk, a premium textile material, was achieved by utilizing a bio-based gardenia blue dye. However, the sharpness of the printing pattern is difficult to control due to the limited water-retention capacity of silk. To address this issue, three polysaccharide derivatives, namely, sodium alginate (SA), low-viscosity hydroxypropyl methyl cellulose (HPMC-I), and high-viscosity hydroxypropyl methyl cellulose (HPMC-II), were employed as thickeners to modify the silk by the dipping-padding method. Firstly, the preparation of the gardenia blue ink and the rheology assessment of the thickener solution were conducted. Furthermore, the impacts of different thickeners on the micro-morphology, element composition, and hydrophilicity of the silk, along with the wetting behavior of the ink on the silk, were analyzed comparatively in order to identify an appropriate thickener for preserving pattern outlines. Lastly, the color features, color fastness, and wearing characteristics of the printed silk were discussed to evaluate the overall printing quality. Research results showed that the optimized ink formulation, comprising 12% gardenia blue, 21% alcohols, and 5.5% surfactant, met the requirements for ink-jet printing (with a viscosity of 4.48 mPa·s, a surface tension of 34.12 mN/m, and a particle size of 153 nm). The HPMC-II solution exhibited prominent shear-thinning behavior, high elasticity, and thixotropy, facilitating the achievement of an even modification effect. The treatment of the silk with HPMC-II resulted in the most notable decrease in hydrophilicity. This can be attributed to the presence of filled gaps and a dense film on the fibers' surface after the HPMC-II treatment, as observed by scanning electron microscopy. Additionally, X-ray photoelectron spectroscopy analysis confirmed that the HPMC-II treatment introduced the highest content of hydrophobic groups on the fiber surface. The reduced hydrophilicity inhibited the excessive diffusion and penetration of gardenia blue ink, contributing to a distinct printing image and enhanced apparent color depth. Moreover, the printed silk demonstrated qualified color fastness to rubbing and soaping (exceeding grade four), a soft handle feeling, an ignorable strength loss (below 5%), and a favorable air/moisture penetrability. In general, the surface modification with the HPMC-II treatment has been proven as an effective strategy for upgrading the image quality of bio-based dye-printed silk.

Sustainable fabrication of fluorescent carbon quantum dots as an optical amplifier in modern agriculture, anti-counterfeiting, food packing and intelligent pH detection

Carbon quantum dots (CQDs) have received a great deal of attention due to their distinctive luminescent features and exciting potential applications in the fields of agronomy, enhanced anti-counterfeiting, drug tracking and intelligent sensing and detection. The focus of the current effort is on easily transforming toxic, non-biodegradable waste expanded polystyrene foam (WEPS) into extremely luminescent CQDs and investigating their various applications. As a nano-priming agent for Cajanus cajan (L.), the green pigeon pea (GPP), WEPS derived CQDs are used. The outcomes showed that seed priming had beneficial effects at all CQDs concentrations (100–900 mg/L), including accelerated seed germination rate, increased shoot and root length, augmented root vigour, higher chlorophyll content and biomass accumulation in comparison to the control groups. The most crucial data coding can be protected under 365 nm UV light using the optimized CQDs concentration (700 mg/L) blue fluorescent ink. In addition, a straightforward sensing platform with high sensitivity and selectivity is needed for the detection of dual metal ions, as well as one with a "turn-on and turn-off" fluorescence (FL) response. Additionally, a composite film containing well-dispersed CQDs (700 mg/L) in polyvinyl alcohol and strong hydrogen-bond interaction is successfully developed to alleviate the FL quenching caused by CQD aggregation. The resulting film had extraordinary FL performance, good mechanical flexibility and high transparency (transmittance of 90 %). Even more remarkably, this luminescent film showed sensitive pH responsiveness, signifying that when pH is stimulated, the FL intensity changed. A smart pH-detector based on this luminescent film is logically created as a proof-of-concept for real-time sensing and detection of pH changes in human sweat. These results show that WEPS derived CQDs have enormous potential as nano-priming agents for seed germination, seedling development, anti-counterfeiting ink, food packaging and intelligent pH-detector in wearable, real-time health monitoring.

Rapid analysis and classification of blue ballpoint pen inks using high-performance thin-layer chromatography and digital color analysis

Despite the rise of digitalization, the scrutiny of paper documents with stamps and signatures remains crucial, constituting 55–60 % of document examination court cases. Developing accessible and robust ink analysis techniques is an ongoing challenge for forensic scientists. To tackle issues related to the identification and classification of dye components in blue ballpoint pens, we have proposed an advanced approach that integrates high-performance thin-layer chromatography (HPTLC), digital color analysis (DCA), and hierarchical cluster analysis (HCA) for a simplified yet effective procedure.The method encompasses multiple development of TLC plates. Initial separation employs methanol:ethanol (4:1, v/v), followed by a second separation using methanol:propan-2-ol:formic acid (1:1:0.1, v/v/v) to achieve cationic dye separation. This TLC development enhances separation selectivity, contributing to a more precise clustering of pen inks. Employing advanced DCA as a processing method for HPTLC, the optimal descriptor for ink classification is identified as the difference between red (R) and green (G) color components. The proposed clustering algorithm achieved 8 distinct ink clusters, showing improved discriminative capability and a reduced variable space compared to well-established or state-of-the-art methods.The approach's robustness was demonstrated across different readout devices, including smartphones and scanners. Reproducibility tests yielded consistent clustering results, confirming the method's reliability. Moreover, the method proved effective in clustering pen ink extracts from paper substrates, showcasing its potential for real sample analysis.This HPTLC-DCA approach presents a simple, cost-effective, and high-precision solution for clustering blue pen inks, significantly enhancing accessibility in high-throughput forensic applications.

Art, pharmacy and history of skin marking and surgical inks in plastic surgery

Plastic surgeons can be distinguished in pre-planning much of their surgery by drawing on the skin. The history of marking the body with ink in plastic surgery goes back to the 1400s. The Sommerlad pen was originally developed at the London Hospital in the 1970s. Sommerlad pens and Bonney’s blue ink allow for a consistent weight of the pen in hand, a reliable source of ink, and an ability to vary the thickness of the line drawn. There has been a suspicion that gentian violet, a component of Bonney’s blue ink, is a carcinogen, resulting in supply problems. Animal models have demonstrated the carcinogenic properties of gentian violet, but evidence to support the carcinogenic potential of gentian violet in humans is sparse. In the surgical setting, we must adhere to using published and described ink formulas. Proprietary formulations lack standardisation, and the compounds used are not always disclosed. The concerning findings of in-vitro and animal models are a valuable addition to our knowledge about these compounds; however, to over-extrapolate and restrict its use on humans as a topical skin marker takes away an important component of a plastic surgeon’s armamentarium.

Viability of organic sources as a sustainable highlighter pen ink

Highlighter pens have been essential tools for students, instructors, and office employees for many years. They are used to emphasize specific information in written texts, making it easier to recognize, remember, and retrieve later. This study proposed the use of organic sources to create solvent-based highlighter pen ink. Specifically, it aimed to determine the viability of using organic sources such as Annatto seeds and blue butterfly pea as sustainable highlighter pen ink and to assess if there was a significant difference between the physical properties of commercial and organic highlighters. An experimental research design was applied, wherein the researchers produced two concentrations of ink and observed which concentration was suitable as highlighter pen ink. The study involved forty (40) students from the College of Education at Laguna University who tested the organic highlighters in one day and answered a validated questionnaire. The results revealed that Annatto seed highlighter pen ink exhibited a more intense color, while blue butterfly pea highlighter pen ink had a mild odor. As a result, respondents strongly agreed on the physical properties of the two organic sources as highlighter pen ink. However, both organic sources resulted in show-through, meaning that the ink could be seen through to the other side, usually due to thin paper or bold ink. Additionally, the study showed that both Annatto seed and blue butterfly pea highlighters were acceptable. However, Annatto seed highlighter was preferred due to its better ink qualities. The research also indicated that there was no significant difference between the physical properties of commercial and organic highlighters, suggesting that highlighter pens made from organic sources can be used as sustainable alternatives. The researchers encouraged further investigation into the advantages of using natural inks derived from organic sources in ecologically friendly and sustainable production methods. This study opens possibilities for utilizing organic materials as alternatives to traditional highlighter pen inks, contributing to environmentally conscious practices in the stationery industry.

Differentiation of blue gel pens using visible spectroscopy coupled with chemometric techniques

Ink analysis is one of the most important and keydimension of forensic document examination (FDE). It is performed to compare, identify, characterize and discriminate different kinds of inks present on questioned document. It becomes key evidence in forensic document examination. In the present work, thirty-eight blue gel pens are discriminated using visible spectroscopy coupled with chemometric techniques. The recorded spectra were visually compared followed by chemometric techniques of principal component analysis (PCA) and linear discriminant analysis (LDA). Discriminating power for visual comparison, PCA and LDA are 58.18%, 100% and 100% respectively. Developed PCA model is validated and 100% accuracy, precision, sensitivity and specificity are achieved. Blue gel pen inks were 100% correctly differentiated on the basis of their brands using PCA followed by LDA. The utilized approach is fast and provides reproducible results. The results of present work demonstrate that potential utility of conventional and cost-effective visible spectroscopy can be improved by coupling it with these chemometric techniques. Major advantage of present research is the minimum damage caused to document. This study establishes a method which provides proof of concept discrimination of the gel pen samples. The methodology adopted in present work can be applied in the alteration cases in examination of suspected documents.

Dual-Ligand Red Perovskite Ink for Electrohydrodynamic Printing Color Conversion Arrays over 2540 dpi in Near-Eye Micro-LED Display.

The lack of stability of red perovskite nanocrystals (PeNCs) remains the main problem that restricts their patterning application. In this work, the dual-ligand passivation strategy was introduced to stabilize PeNCs and inhibit their halogen ion migration during high-voltage electrohydrodynamic (EHD) inkjet printing. The as-printed red arrays exhibit the highest emisson intensity and least blue shift compared with samples with other passivation strategies under a high electric field during EHD inkjet printing. Combining with blue and green PeNC inks, single-color and tricolor color conversion layer arrays were successfully printed, with minimum pixel size of 5 μm and the highest spatial resolution of 2540 dpi. The color coordinate of CsPbBrI2 NCs arrays are located close to the red point, with a color gumat of 97.28% of Rec. 2020 standard. All of these show great potential in the application of color conversion layers in a near-eye micro-LED display.

Application of Raman spectroscopy in relative blue ballpoint pen ink dating for forensic document analysis – a case report

In this case report, blue ballpoint ink on a questioned document was investigated using a newly developed Raman model devoted for dating of documents via writing inks. The majority of blue ballpoint pen inks contain crystal violet - a triarylmethane dye which displays a typical “molecular fingerprint” type of Raman spectrum, of which most intense peaks at 749 cm−1 and 1542 cm−1 (under 785 nm laser excitation) represents the least and the most stable bonds of crystal violet molecules, respectively. The ratios of peak intensities at above mentioned Raman shifts are utilized to estimate the relative dating of the questioned blue ballpoint pen ink in practice, results of which agreed with estimations using other traditional relative dating methods. ® 2023 Journal of Science and Technology - NTTU

Preparation of deep-eutectic solvent and study on the detecting methods of crystal violet by deep-eutectic solvent

This paper prepared deep eutectic solvent using choline chloride (hydrogen bond acceptor) and phenol (hydrogen bond donor) as raw materials in molar ratio of 1:3. The prepared DES showed hydrophobic properties, sodium carboxymethyl cellulose was used as an emulsifier to pretreat crystal violet (CV), and the prepared DES was used as an excellent extractant to extract CV for detection. Ultraviolet spectrophotometry was used to determine the absorbance of CV after extraction to calculate the corresponding extraction concentration. In addition, the influences of external influencing factors, such as appropriate extractant and emulsifier, required centrifugation time, and proper pH on the experimental results were also explored. Under the optimized conditions, the detected content of CV (pH = 4, centrifugation time 10 min) showed good linear relationship in the range of 5∼40 mg/L, the limit of detection (LOD) and quantification (LOQ) were 1.01 μg/L and 1.53 μg/L. The proposed method was applied to blue frame label paper and blue ball ink commonly used in the laboratory as the determination method of marking experiments. As a result, the recovery rates obtained were more than 80 %, confirming the feasibility of the proposed method.

Silk‐Based Functional Inks with Color‐Tunable Light Upconversion for Printing on Arbitrary Surfaces

AbstractA biocompatible and versatile silk‐based functional ink with hydrophilic upconversion nanoparticles (UCNPs) that can be printed or painted on arbitrary substrates, including biological surfaces is demonstrated. Hydrophilic UCNPs, ready to be dispersed in aqueous silk fibroin solution, are synthesized in large quantities via facile hydrothermal synthesis using citric acid. Based on a systematic study of dopant control to achieve robust red emission from citrate‐capped UCNPs, three primary colors are obtained, which serve as the basis for the expansion of the color palette. The synthesized UCNPs are homogeneously dispersed in regenerated silk fibroin solutions derived from Bombyx mori cocoons to produce water‐based functional inks. Cyan, magenta, and yellow (CMY) inks are created by combining red, green, and blue (RGB) inks. Demonstrator devices, where a variety of colorful patterns and codes are revealed only under near‐infrared irradiation, are realized through stencil printing or brush painting on flexible polymer films, fruit, leaves, silkworm cocoons, and pig skin. The patterns and codes are highly heat resistant (≈230 °C) and can be easily washed off with water after use. The printable/paintable inks and functions proposed here will provide new opportunities for applications where sustainability, biocompatibility, and intentional luminescence are simultaneously required.

Plant-based ink properties and storage stability for inkjet printing.

In this sustainability-oriented research, the properties of plant-based inks were evaluated denoting the viscosity range of 8.5 to 10 cP, the relative density of 1.06, conductivity value of 2.51 mS/cm, and the surface tension of 60 mN/m and pH of 4.9 to be most effective for inkjet printing. The changes in these properties to the one-month storage phase are detailed as determined with attenuated total reflectance - Fourier transform infrared spectroscopy, viscometer, and tensiometer. The varied colours of plant-based inks were stable to storage time except for the blue colour ink made from bio indigo herb that displayed agal-like sediments. After the storage phase, the plant-based inks exhibited anti-thixotropic viscosity except for yellow colour plant-based ink demonstrating thixotropic behaviour. High conductivity values of 18.5 and 15.6 mS/Cm were noted for blue and black colour plant-based inks, indicating their potential for constituting conducting inks; however, the conductivity values dropped to 7.5 and 9.5, respectively, after 1 month. The pH and surface tension were found steady during the storage period. The study of the life cycle analysis of plant-based inks is suggested for future work. The significance of this work in developing plant-based inks for inkjet printing of textiles lies in the convergence of sustainability and innovation. Plant-based inks can offer an eco-friendly alternative to traditional synthetic inks that are used currently, which provides a knowledge base for good practises meeting the environmentally conscious in the digital printing of the textile industry. These developed inks from this study can not only reduce the environmental impact but also promote a healthier ecosystem.

Analysis of blue and green REACH compliant tattoo inks.

The Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) legislation in Europe has limited the use of certain materials in the manufacturing of tattoo inks; in particular, Pigment Blue 15:3 and Pigment Green 7 have been banned for the use in tattoo inks and permanent makeups and all labels must include an accurate list of ingredients. This study analyzed green and blue inks from five different manufacturers distributed to the European market, all of which claim to be REACH compliant. Nine out of ten inks analyzed were found to not be compliant and four contained banned material. The polymorph of Pigment Blue 15 found in four inks was unable to be determined. The majority of inks showed labeling inaccuracies, including the addition of unlisted poly(ethylene glycol) and propylene glycol. This study highlights issues around REACH compliance of tattoo inks on the European market and the need for manufacturing protocols to ensure accurate labeling.

Rapid synthesis of ultra-bright blue and cyan CQDs fluorescent powders based on chemical dispersion and concentration effects

It is often impossible to obtain solid carbon quantum dots (CQDs) fluorescent powder by direct drying due to a self-quenching effect, which limits their large-scale application. Here, we first report a general method for rapidly conversing CQDs solution into fluorescent powder via a crosslinking reaction of 3-glycidyloxypropyltrimethoxysilane (KH-560). Initially, N-doped CQDs (N-CQDs) with an ultra-high quantum yield (QY) of 98.45 % and concentration-dependent luminescence behavior were synthesized via a straightforward hydrothermal reaction involving citric acid and ethylenediamine. The N-CQDs solution at low and high concentrations emits blue and cyan fluorescence under ultraviolet light, respectively. By the action of aqueous ammonia, KH-560 quickly forms a gel matrix at room temperature to realize the dispersion and anchor of N-CQDs to prepare N-CQDs fluorescent powder (NK). NK not only inherits the strong luminescence performance (QY = 71.87 %) of N-CQDs but also exhibits excellent fluorescence stability, successfully applied in blue and cyan LED lighting and fluorescent ink.

A rare cases of ferrous sulphate poisoning- A case study

A poison is a substance which when administrated, inhaled or ingested is capable of causing deleterious effect on the human body. The circumstances may be suicidal, homicidal or accidental. A suicidal poison of choice must be cheap, easily available and capable of being administered is any food or drink. It must have pleasant taste and no repulsive smell. The action of poison may be local, remote, combined and general. The preparations of iron salt, which are largely used in medicine are mostly prepared from sulphate, carbonate and perchloride of iron. When these salt are administered in large doses, they produce poisonous symptoms and may even cause hemosiderosis as a manifestation of chronic poisoning. Iron sulphate (ferrous Sulphate, FeSo4) is commercially known as green vitriol of sulphate. It forms green, efflorescence monosymmetric crystals on exposure to the atmosphere. It is freely soluble in water. It is used in making blue ink and dyes, but sometimes as a pesticide. In this case study, we'll talk about a woman who died after consuming an corrosive drug at home. For medico-legal purposes, it was critical to correlate autopsy results with medical care records and the place of the incident.