Disperse Dyes Research Articles

Understanding and simulating mechanochromism in dye-dispersed polymer blends: from atomistic insights to macroscopic properties.

In this work, we propose a computational protocol enabling the simulation of mechanochromic responses in dye-dispersed polymer blends. The main objective is the modeling of the molecular-level structural changes responsible for the modulation of the photophysical properties that lead to the mechanochromic phenomenon. In this demonstrative study, we focus on predicting the changes in optical absorption displayed by a model system consisting of a dimer of a tetraphenylethylene derivative dispersed in a polyethylene matrix. The blend is subjected to an external stimulus that causes a modulation of the polymer matrix density that translates, in turn, into the emergence of specific mechanical constraints on the optically active dimers. The accurate description of this phenomenon requires the reliable sampling of the dimer configurations induced by the interaction with the matrix under stress. These molecular geometries are associated with modified electronic structures that confer novel absorption responses to the dispersed dyes. In the present contribution, the sampling of these structures is achieved through classical molecular dynamics (MD) simulations including a model element to apply an anisotropic mechanical force. This element allows the microscopic modeling of the chains' and dyes' structural rearrangements under stress. After the sampling, we compare the results of two approaches for the prediction of the optical response: (i) the calculation of a mean response from a statistical average over quantum chemical calculations on the sampled MD structures and (ii) a prediction via a more expensive hybrid scheme allowing the relaxation of the sampled molecular geometries in the presence of the matrix constraints.

Preparation of grafted starch‐based cationic flocculants and its removal of reactive and disperse dyes

AbstractIn this paper, a starch‐based flocculant (ADSt) with medium and low temperature solubility and enhanced flocculation effect was synthesized using corn starch, acrylamide, and dimethyldiallyl ammonium chloride as main materials by the ethanol‐alkali method and grafting method. The main mechanism of ADSt's flocculation was electrical neutralization and bridging. The flocculation performance of ADSt was verified by using it along with polymeric aluminum chloride (PAC) as coagulant/flocculant, dispersible dye (dispersible yellow RGFL), and reactive dye (active trimeric blue KN‐G) to simulate dye wastewater. For the dispersed yellow water sample and active emerald blue water sample, the dosage of PAC was 40 and 35 mg/L respectively. When the dosage of ADSt was 10 mg/L with a dye content of 100 mg/L, the decolorization rates for both dyes reached up to 96.2% and 94.4% respectively. The properties of the flocs such as size and two‐dimensional fractal structure were described. The prepared ADSt maintained a good flocculation effect in the pH range of 5–9 due to its excellent water solubility achieved through the ethanol‐alkali preparation process, where its solubility reached 86.7% at 30°C. Overall, the preparation process for ADSt is simple, cost‐effective, while providing an effective solution for treating printing and dyeing wastewater.

Synthesis and characterization of aniline-based azo molecules: In vitro pharmacological and emission studies.

The present work involves the synthesis of novel dispersed mono-azo dyes using different coupling components and 2-methoxy-5-nitro aniline as amine through a simple and convenient diazo-coupling method. The structures of the newly synthesized mono azo dyes were confirmed by using various spectral techniques such as 1H NMR, Fourier transform infrared, and high-resolution mass spectrometry. At room temperature, the electronic absorption spectra and fluorescence spectra of the synthesized mono azo dyes were recorded with different solvents. The global reactive parameters for the synthesized azo molecules were evaluated by performing density functional theory through the 6-311++G (d, p) basis set. The anti-microbial activities for the synthesized azo compounds were carried out, and the compounds G1 and G2 exhibited good antibacterial and anti-fungal activities. The in silico molecular docking studies of the azo molecules revealed that all the compounds exhibited extraordinary binding affinity as that of the standard drug. Further, the anti-tuberculosis study against the Mycobacterium tuberculosis for the synthesized azo dyes was evaluated, and from the results, it was revealed that the compound G4 showed good sensitivity among the other synthesized azo compounds.

Enhancing the coloration of polypropylene surfaces through low-frequency plasma modification with disperse dyes

This study focuses on the effective coloring of nonwoven polypropylene surfaces, achieved through the application of oxygen and nitrogen plasma treatments in a vacuum environment using cold plasma. Various plasma durations were employed to introduce experimental diversity into the samples. Following surface modification, dispersal dyeing based on benzenesulphonamide was performed. To evaluate the impact of surface modification, comprehensive characterization tests, including SEM, FTIR-ATR, XRD, and XPS, were conducted. Performance effects were scrutinized through color spectrum values (CIE L*, a*, b*, and K/S values), tearing strengths and contact angle measurements. Furthermore, fastness tests for washing (color change and staining) and for rubbing (dry and wet) were carried out to examine the effect of surface modification on dyed polypropylene nonwoven fabrics. According to the test results, a notable increase in K/S values was observed after plasma treatments. The impact of nitrogen and oxygen plasma treatment on polypropylene surfaces was comprehensively evaluated, considering performance properties across all characterization processes.

Epoxy composite microspheres as a versatile platform for enhancement of chlorophyll dispersion and photostability in coatings

Chlorophyll (Chl), as a rich natural pigment, is limited in applications due to poor photostability. The hydrophobic properties of Chl attributed to the tetrapyrrole ring and terminal long-chain hydrocarbons further constrains its dispersion in aqueous coatings. In this work, chlorophyll/epoxy composite microspheres (Chl/EMs) were prepared as candidate pigments via emulsion polymerization to provide a versatile platform for enhanced dispersion and photostability. The optimal reaction temperature of 75 °C for achieving the appropriate particle size distribution of epoxy microspheres (EMs) was first determined. Chl/EMs were then prepared by (1) the combination of Chl and DGEBA in the emulsification process, or by (2) mixing Chl with m-xylylenediamine (MXDA) during curing. The effects of Chl introduction at different steps on the emulsification, curing agent diffusion, and curing process were studied using off-site microscopy observation and aggregation-induced emission technique, to clarify the structure and morphology evolution during emulsion polymerization. The particle size of the microspheres was mainly determined by the emulsification process of the epoxy precursor. Chl participates in emulsification of Chl/EMs in case (1), resulting in a large average particle size and poor particle size distribution. In case (2), the diffusion of MXDA into epoxy emulsion particles is completed within 30 min and does not impede the quicker diffusion process of Chl which was mixed with MXDA. The prepared Chl/EMs with size ranging from 1 to 10 μm create a conducive oxygen blocking environment. Compared to the complete degradation period of untreated Chl coatings, the photostability of Chl/EMs coatings increased nearly 7-fold. Remarkably, Chl/EMs exhibit superior dispersion capability in waterborne polyurethane coatings compared to pure Chl coatings. The EMs with controllable morphology and size can be used as a versatile platform for enhancing dispersion and photostability of other organic or natural dyes and pigments in waterborne coatings.

Refinement of intranasal delivery in rats: A cadaveric study.

The intranasal route enables direct delivery of multiple substances from the nose to the brain, through olfactory and trigeminal pathways, bypassing the blood-brain barrier and avoiding systemic absorption. Despite the potential of this route, the various administration approaches make data reproducibility and interpretation challenging, emphasizing the necessity to establish a consistent methodology. Considering this, the aim of our study was to assess and compare the distribution of two dye volumes (30 µl and 50 µl) in the nasal cavity of rat cadavers. We employed three distinct methods of intranasal delivery: nose drops, by pipette tip, or cannula inserted into the nasal cavity. The results indicated that for both volumes, using the nose drops and the pipette tip methods, the dye dispersion occurred mainly in the vestibule, respiratory and olfactory regions, without reaching the olfactory bulbs. Using the cannula method, the deposition predominantly occurred in the respiratory and olfactory regions, with the dye reaching 66.7% and 100% of the olfactory bulbs, respectively, to low and high volume. Furthermore, the results demonstrated differences between the two volumes, in the pharynx, larynx, trachea, septal window, and incisive papilla, where an increased dye presence was observed with the 50 µl instillation across all three methods. According to our results, the intranasal delivery with a cannula was the most effective method for dye deposition in the olfactory region. However, further studies in live animals will be necessary to determine and refine the administration method that consistently allows specific deposition in the olfactory system.

Photophysical properties and photostability of novel 2-amino-3-benzothiazole thiophene-based azo disperse dyes

The design, synthesis, and use of four new thiophene-based dispersed azo dyes with salicylic and carboxylic acid acceptors are shown in this work. The produced dyes exhibit a wide range of light absorption characteristics, including near UV–visible, and deep red wavelengths. PG9 and PG12, which are thiophene disperse azo dyes with carboxylic acid acceptor, showed red-shifted absorption, but PG10 and PG11, which are azo dyes with salicylic acid, showed blue-shifted absorption. The synthesized dyes exhibited good photostability in solvents. The experimental results are supported by theoretical results from Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT).Furthermore, the dyes exhibit outstanding dyeability with percentage exhaustion characteristics of 90% when applied to acrylic, nylon, and polyester fabrics. Rich shades ranging from deep orange to black are seen in the dyed fabrics. Salicylic acid acceptor-dyed materials have higher K/S values when applied to nylon-dyed fabrics, while acrylic and polyester-dyed fabrics respond better to carboxylic acid acceptor dyes. The fabrics that have been colored display exceptional light, wash, and rubbing fastness. Inlight and wash fastness, polyester-dyed fabrics performed better than acrylic and nylon-dyed fabrics. Studies on UV protection show that fabrics with high UPF ratings canblock damaging UV-A and UV-B radiation efficiently. All synthetic dyes have their antibacterial activity assessed using the AATCC 100 test method, which is associated with the HOMO-LUMO energy gap.

Dyeability and hydrolytic degradation of polylactic acid fibers under different environments

Polylactic acid (PLA), a biodegradable material derived from industrial crops such as corn and straw, is increasingly recognized in various sectors, including textiles, food, and medicine. However, the dyeability and biodegradability of PLA a key factor contributing to its growing popularity. Herein, we report a sustainable dyeing method for the coloration of PLA fibers with excellent fastness using dispersed dyes. The results showed that the dyed PLA fabric exhibited a K/S value of 8.4, along with impressive grade 4 fastness to both dry and wet rubbing. Additionally, the dyed PLA fabric exhibited increased hydrophilicity and enhanced surface roughness. Most importantly, during the hydrolytic degradation experiment, the dyed polylactic acid fabric experienced a notable 36 % decrease in quality when exposed to a water environment characterized by a pH of 11, a temperature of 40 °C, and a duration of 60 days, whereas the control PLA fabric is only 8 %. The hydrolytic degradation of PLA occurs at its fastest rate when the color of the dye is at its optimal intensity, the environmental temperature is elevated, and the pH level is in an alkaline state. The degradation rate of PLA fabric initially tends to be rapid, followed by a gradual slowdown. This research may provide a useful guideline for the proper storage of dyed PLA fabrics and their use in the textile industry.

Synthesis and characterization of sustainable blue dyes: Enhancing diffusion on nylon fabrics with supercritical CO2 for eco-friendly dyeing methods

A very convenient method was developed to synthesize five dispersed anthraquinone dyestuffs using the readily available starting material 1,4-diaminoanthroquinone. This dye was prepared for coloration on nylon fabrics with supercritical carbon dioxide (ScCO2). All the synthesized dyes were characterized by 1H NMR, 13C NMR, and HRMS techniques. The UV-Vis absorbance measurements for all the dyes were carried out, and the results indicated that the absorption peak wavelength of the dyes was approximately 570–641 nm in the blue region. Further, these dispersed dyes were dyed on nylon fabrics with supercritical CO2. After dyed fabrics were tested, the color strength of K/S value and color fastness were tested using like washing, crocking, and sunlight. Additionally, it determines the sweat fastness of dyed nylon fabrics under acidic and basic conditions. The dyes are readily involved in the nucleophilic addition of amino (-NH2, nylon) functional groups to nylon fabrics in an alkaline medium. Therefore, our results showed that these dyes are commercially the most satisfactory, environmentally efficient dyes and practically exhibit sufficient color uniformity.

Multi-site sulfonation of lignin for the synthesis of a high-performance dye dispersant

Sulfonated lignin-based dye dispersants have intensively attracted attention due to their low cost, renewability and abundant sources. However, their utilization is limited by the low content of sulfonic groups and high content of hydroxyl groups in their complex lignin structure, which results in various problems such as high reducing rate of dye, severe staining of the fibers and uneven dyeing. Here, the multi-site sulfonated lignin-based dispersants were prepared with high sulfonic group content (2.20 mmol/g) and low hydroxyl content (2.43 mmol/g). When using it as the dispersant, the dye uptake rate was improved from 69.23 % to 98.55 %, the reducing rate was decreased from 20.82 % to 2.03 %, the K/S value was reduced from 0.69 to 0.02, and the particle sizes in dye system before and after high temperature treatment were stabilized below 0.5 μm. Besides, the dispersion effect was significantly improved because no obvious separation between dye and water was observed even if without the assistance of grinding process. In short, the multi-site sulfonation method proposed in this work could remarkably improve the performances of the lignin-based dye dispersants, which would facilitate the development of the dye dispersion and the high value utilization of lignin.

Investigation of the Dyeing Ability of Some Reactive Triazine Azo Dyes Containing Pyrazole Fragment.

The IR, 1H NMR, and DFT studies indicated that the prepared reactive disperse dyes predominately exist as hydrazone tautomers. The electronic absorption spectra in methanol were observed and compared to those computed using B3LYP/6-311G(d,p). The dyeing efficiency of the produced dispersed reactive dyes was examined on polyester, cotton, and polyester/cotton blended fabrics. The degree of exhaustion and the quick properties of the dyed samples in terms of perspiration, washing, scorch and light fastness were assessed. It was found that reactive disperse dyes under investigation have a higher affinity for dyeing polyester textiles than cotton textiles. Moreover, the reflectance and color strength of the synthesized dyes were measured and discussed.

Advancements in laser-based spatiotemporal measurements of flow boiling

Recent advancements in laser and imaging systems, as well as in computational processing capabilities, have made quantitative optical imaging, which is often combined with laser illumination, highly adaptable, robust and reliable. Laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), offer the possibility of simultaneous spatiotemporally resolved measurements of temperature fields in the liquid phase at boiling conditions. In this paper, we examine the applicability of two-colour PLIF (2cPLIF), where the ratio between individual fluorescent emissions from uniformly dispersed dyes is used to take temperature measurements in the liquid phase in the presence of moving vapour-liquid interfaces typical of boiling flow. The implementation of 2cPLIF necessitates uniformity in the concentration of different dyes across the flow field. However, in the case of a multiphase flow such as boiling, thermophoresis can lead to inhomogeneous dye distributions. To overcome this challenge, a single-dye multispectral planar laser-induced fluorescence (SDMS-PLIF) method has been developed, which employs fluorescent emissions in different spectral bands of the same dye (Nile Red). The spectral characteristics of Nile Red were measured using a spectrometer to identify its temperature-sensitive bands over a wide range of dye concentrations, from 0.3 to 30 mg/L. Following this, we demonstrate the measurement capabilities of SDMS-PLIF thermography as applied to a boiling flow in a miniaturised vertical square channel, gaining insight into the thermohydrodynamic interactions between vapour bubbles and a heated wall.

Synthesis, Spectroscopic, Computational, and Biological Evaluation of Pyrazole mono azo dyes

In the present work, a series of new dispersed mono azo dyes (3) were synthesized through conventional diazo-coupling reaction between 4-hydroxy-phenylacetamide with pyrazole derivatives at low temperature. All the synthesized mono azo compounds were characterized by various spectroscopic methods like IR, NMR, electronic spectral, LC-MS, and fluorescence spectral studies. The experimental IR data was compared with that of the theoretical data and it has been observed that, the experimental IR spectral values are found to be lower than that of the theoretical values. The quantum chemical calculations were also carried out to understand the chemical reactivity of the compounds by using B3LYP method in conjugation with 6-311++G (d, p) basis set. The compounds were screened for anti-tuberculosis properties against M. tuberculosis and the compound 7 was found to exhibit a significant inhibitory effect with MIC value of 12.5μg/mL. The anti-microbial studies were carried for synthesized mono azo compounds. Further, the in silico molecular docking study was carried out to know the significant interaction of the synthesized compounds against VEGFR2 target protein.

Investigating the effect of anchoring groups modified comb-like polycarboxylate hyperdispersants on dispersion and stability in dispersed dyes

Comb-like hyperdispersants are widely used for the dispersion of liquid dispersed dyes (LDDs), because of the molecular structure of comb, in which the effective steric hindrance effects provided by polymer side chains and the adsorption force provided by anchoring groups, resulting in the dispersant to be firmly adsorbed on the surface of the dye. However, the mechanism by which the anchoring groups in this dispersant affect the dispersion and stability of LDDs is still unclear. Herein, three types of anchoring group modified comb-like polycarboxylate hyperdispersants were synthesized to explore the effect of anchoring groups on stability and dispersibility, in which the anchoring groups from the monomers of 2-vinylnaphthalene (2-VNP), styrene (St), and 4-vinylbiphenyl (4-VBP). The optimal sand grinding conditions and dispersion stability of the modified hyperdispersants were comprehensively investigated. 2-VNP modified hyperdispersant (DPN) possessed higher grinding efficiency and better dispersion stability than those of St (DPS) and 4-VBP modified hyperdispersants (DPB). The results of atomic force microscope (AFM) and quartz crystal microbalance (QCM) indicated that DPN exhibited higher adsorption force (2.16 mN/m) than that the DPS (0.648 mN/m) and DPB (1.56 mN/m), thereby improving the adsorption strength of dispersants and DDs, stabling the dispersion effect of LDDs. In addition, the dyeing performance of the prepared LDDs on polyester fabric was further investigated. It was found that these LDDs acquired a faster dyeing rate, higher K/S values and rubbing color fastness, and lower chemical oxygen demand (COD) of residual liquid than commercial powder DDs, due to the higher adsorption force on the DDs surface provided good colloidal stability in the high temperatures dye bath. We expect that this study will provide important mechanistic insights into the development of hyperdispersants for LDDs controlled by high adsorption force anchoring groups.

Microleakage effect of in-office bleaching on two types of nanohybrid composites with or without surface sealer.

Bleaching is a highly common method used nowadays to treat tooth discolouration because it is a significant cosmetic issue, particularly with anterior teeth, however bleaching itself results in microleakage. This study aims to evaluate the impact of in-office bleaching on class V restoration microleakage with type 1 and type 2 composite restorations. Three hundred and twenty healthy, caries-free removed human anterior teeth were used in this in-vitro study. All extracted teeth had their buccal and lingual surfaces uniformly prepped for class V cavities. The 120 removed teeth were divided into two groups, with Group 1 receiving Tetric N-Ceram nanohybrid composite restorations and Group 2 receiving 3 M Filtek Z350 XT nanohybrid composite restorations. Groups 1 and 2 were further broken into four more subgroups of four each. The restorations were sealed with a G-Coat Plus resin. The p-value was kept at 0.005 for the data analysis using the Chi-square and Fisher exact tests. Allocating microleakage among 320 study models revealed that 141 (44.1%) study samples had no microleakage, whereas 20 (6.3%), 54 (16.9%), and 105 (32.8%) study samples had microleakage up to, between, and greater than two-thirds of cavity depth. With a statistically significant p-value of 0.001, no microleakage was discovered in 85 (53.1%) lingual surfaces with Tetric N-Ceram nanohybrid composite restoration and 56 (35%) buccal surfaces with 3M Filtek Z350 XT nanohybrid composite restoration. 19.1% of samples of N-Ceram that were sealed and not bleached had no microleakage, according to analysis of microleakage across several groups. With a p-value of 0.001, the distribution of microleakage among various clusters was statistically notable. According to the findings of the study, hydrogen peroxide bleaching has an enhanced impact on micro escape during dye dispersion. Both with and without bleaching, resin coating can be utilised to minimise marginal microleakage.

Characterization of conductive particle dispersion in textile coatings through Joule’s effect monitoring analysis

Achieving proper dispersion of pigments, dyes, or other additives, such as microcapsules or nanoparticles, within printing pastes or textile coatings is crucial for obtaining a homogeneous result. In certain specialized applications, such as coloration technology, it is possible to use colorimetry tools, visual examination, and even artificial vision to identify defects. However, none of these techniques comprehensively map the specific additive distribution. This paper proposes a novel approach: monitoring the distribution of conductive particles (graphene nanoplatelets, referred to as GNPs) within an acrylic coating paste using the Joule’s effect. Four different dispersion systems (ultrasound mixer, blender, toroidal agitation, and three-roll mill) are employed. Thermographic images provide an accurate view of how conductive particles are distributed. This complements data from numerical values, such as the maximum and average temperatures recorded for each sample. In certain cases, relying solely on numerical values can be inadequate or insufficient, hence the novelty of this article emphasizing the significance of using the Joule’s effect to assess the distribution of conductive particles. Concerning the mixing systems, optimal dispersion of GNPs in distilled water is most effectively achieved using an ultrasound mixer, with enhanced uniformity as dispersion time increases. For mixing the components of the coating paste, the toroidal agitation method yields the best result. Employing the three-roll mill is discouraged for this application due to its propensity to induce phase separation.

Optimizing cyanine dye properties for enhanced dyeing and inkjet printing on diverse Substrates: Photophysical and colorimetric investigations

Cyanine-based cationic dyes with different substituents in the donor unit were easily synthesized using readily available starting materials. The prepared dye molecules were spectroscopically characterized by NMR, FT-IR, and HR-Mass, and their thermal stability was measured by TGA, DSC, and XRD. Based on the TGA and DSC measurements, it was concluded that all the dyes are thermally stable up to 200 °C. Also, powder XRD was studied for all dyes to identify the explicit crystallinity and morphological nature of the dyes. A dye dispersion solution was prepared for the proper dyeing of modacrylic fabric and the dyed fabric showed good color strength K/S for dyes R1, R2, and R6 and fragile color strength for R3, R4,and R5. These dyes are also used for printing on substrates like paper and fabric using ink-jet printing. These dyes were also used for transferability printing applications on various fabrics.

Synthesis of novel azo pyrazole disperse dyes for dyeing and antibacterial finishing of PET fabric under supercritical carbon dioxide

Supercritical carbon dioxide (scCO2) has been suggested as a good substitution to environmentally harmful water-based tincturing. The present study describes the successful synthesis of some biologically active dispersion tinctures for supercritical carbon dioxide tincturing of polyester fabric. The coupling of 1-cyanoacetylpiperidine (1) with the diazonium salt of aryl amine derivatives (2a–d) produced 1-((aryldiazenyl) cyanoacetyl piperidines (3a–d). To create the derivatives of 4-(phenyldiazenyl)-5-(piperidin-1-yl)-1H-pyrazol-3-amine (5a), the propane nitriles (3a–d) were condensed with hydrazine hydrate. However, the unexpected 3-aminopyrazol-5-ol yellow–red dispersion dyes (4a–d) were identified as the reaction results. The MS, IR, and NMR spectra were used to describe the novel dyes, and the results exactly matched the suggested structures. The antibacterial test, which was conducted using the AATCC method, revealed that some of the compounds (3a–d) and (4a–d) had impressive antibacterial capabilities against the researched +ve and gram −ve bacteria. For eight dyestuffs, the dyeability, color strength, and color fastness of the tincturing process were evaluated. The evaluation focused on determining color uptake using a gauge for color strength (K/S). All dyes displayed excellent rubbing, washing, and light fastness (color change and staining grade of 4–5).

Synthesis of Amphiphilic Block Copolymer and Its Application in Pigment-Based Ink.

Amphiphilic block copolymers-based aqueous color inks show great potential in the field of visual communication design. However, the conventional step-by-step chemistry employed to synthesize the amphiphilic block copolymers is intricate, with low yield and high economic and environmental costs. In this work, we present a novel method for preparing an amphiphilic AB di-block copolymer of PCL-b-PAA by employing a combined polymerization strategy that involves both cationic ring-opening polymerization (ROP) of the ε-caprolactone monomer and the reversible addition-fragmentation chain-transfer (RAFT) polymerization on the acrylic acid monomer simultaneously. The corresponding polycaprolactone (PCL) and polyacrylic acid (PAA) serve as the hydrophobic and hydrophilic units, respectively. The effectiveness of the amphiphilic AB di-block copolymer as the polymeric pigment dispersant for water-based color inks is evaluated. The amphiphilic AB di-block copolymer of PCL-b-PAA exhibits a molecular weight of 1400 g mol-1, which is consistent with the theoretical value and suitable for polymeric dispersant application. The high surface excess (Γmax) of the PCL-b-PAA in water indicates a densely packed molecular morphology at the water/air interface. Additionally, micelles can be stably formed in the aqueous PCL-b-PAA solution at very low concentrations by demonstrating a low CMC value of 10-4 wt% and a micelle dimension of approximately 30 nm. The model ink dispersion is prepared using organic dyes (Disperse Yellow 232) and the amphiphilic block copolymer of PCL-b-PAA. The dispersion demonstrates near-Newtonian behavior, which is highly favorable for the application as inkjet ink. Furthermore, the ink dispersion displays a low viscosity, making it particularly suitable for visual communication design and printing purposes. Moreover, the ink dispersion demonstrates an unimodal distribution of the particle size, with an average diameter of approximately 500 nm. It retains exceptional stability of dispersion and even conducts a thermal aging treatment at 60 °C for 5 days. This work presents a facile and efficient synthetic strategy and molecular design of AB di-block copolymer-based dispersants for dye dispersions.

Multifunctional bioretention basins as urban stepping stone habitats for wildflowers and pollinators

Sustainable Urban Drainage Systems (SUDS) are increasingly used to manage precipitation events in cities and create decentralized stormwater management. To enhance ecological benefits of bioretention basins, we investigated development of native forb communities composed of 26 plant species common in northwest Europe, their provision of foraging resources, and functional connectivity between basins for pollinating insects. We used two types of engineered infiltration soil to test effects of growing conditions on plants in four basins under field conditions over three years, and in a controlled environment. Hemi-rosette grassland forbs associated with neutral to calcareous sandy soils tolerated the environmental conditions and persisted during early succession, while there was no effect of infiltration soil on community composition. Furthermore, colonisation by non-sown spontaneous plants was limited, but differed between soil types. Sown forbs and spontaneous wildflowers contributed foraging resources to local pollinators. Fluorescent dye was moved between forbs in all basins, while bi-directional dye dispersal up to 86 m demonstrated basins facilitate functional connectivity for pollinating insects whereby structurally disconnected basins contribute as stepping-stone habitat patches. Finally, in the controlled experiment testing the effect of soil types on plant growth (aboveground biomass) and reproduction (floral units) of eight native forbs, results indicated that infiltration soils should maximise organic content to enhance species richness in bioretention basins, albeit without compromising system performance. Despite low replication in the field study, we demonstrate bioretention basins can support urban biodiversity conservation by providing valuable foraging habitat and functional connectivity for pollinators while requiring minimal management.