Spray coating thin polymeric sensor films for Au3+

A novel polymeric sensor of the poly(sodium-4-styrenesulfonate) (PSS)-modified rhodamine B derivative (Rho) was synthesized using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N,N′-dimethylpyridin-4-amine (DMAP) as coupling reagents to obtain PSS-Rho4 in 21% yield. The characterization and “Off–On” sensing phenomena were established through UV–Vis, fluorescence, NMR, and FTIR techniques. The PSS-Rho4 showed high selectivity and sensitivity for Au³⁺ over other metal ions. Upon the addition of Au³⁺, significant color change and “Off–On” fluorescence were observed due to a cation Au³⁺ induced spirolactam ring-opening process with detection limit down to micromolar values (1.2 μM). In addition, spray coating thin polymeric sensor films were produced onto the surface of material (PSS-Rho4-ITO and PSS-Rho4-filtered paper) providing a fast, portable, and easy-to-use molecular device for the detection of Au³⁺ in the real system. Reversibility was evaluated by rinsing with EDTA solution under basic condition. We believe that, this approach provides a sensitive and accurate method for the detection of Au³⁺ in environmental and biological applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48273.     

Cu2+ sensing via noncovalent complexes of fluorescent whitening agents and imidazole-based polymeric dye transfer inhibitors

Fluorescent whitening agents (FWAs) and polymeric dye transfer inhibitors (DTIs) are widely used in detergent formulations to combat garment yellowing, fading, and discoloration. We report a new application for these inexpensive, mass-produced, laundry additives as sensitive fluorescence “turn-off” sensors for Cu²⁺. We show that Cu²⁺-sensitive FWA–DTI complexes form spontaneously when aqueous solutions of FWA and imidazole-based DTI are mixed. We also show that the imidazole groups present in the resulting fluorescent FWA–DTI complex selectively bind Cu²⁺, a potent fluorescence quencher, to form nonfluorescent FWA–DTI-Cu²⁺ complexes. Our Cu²⁺-sensing FWA–DTI complexes are completely water-soluble and have a Cu²⁺ detection limit of ~ 0.14 μM in water. Our simple approach not only converts the Cu²⁺-insensitive FWAs into sensitive fluorescent probes for the metal ion but also significantly enhances the brightness of triazinylaminostilbene FWAs. The present study provides a facile, synthesis-free strategy for producing inexpensive fluorescent sensors for Cu²⁺. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48915.     

Pyrene‐functional star polymers as fluorescent probes for nitrophenolic compounds

Novel tetra‐armed star‐shaped styrenic copolymers with pyrene side groups [ (S1‐S3)‐Pyr ] were prepared and employed as fluorescence sensing probe for fast and sensitive determination of nitroaromatic compounds. (S1‐S3)‐Pyr depicted characteristic pyrene monomer emission signals as well as broad excimer bands in their fluorescence emission spectra due to close proximity of the pyrene groups on the polymer chains and the ratio of monomer to excimer emission intensities gradually decreased as the pyrene content of the star polymers were increased from S1‐Pyr to S3‐Pyr . The highest quenching efficiency in the presence of 25 equivalent nitroaromatics was observed for 2,4,6‐trinitrophenol/picric acid (99.4%) followed by 2,4‐dinitrophenol (84.2%), 4‐nitrophenol (82.6%), 2,4,6‐trinitrotoluene (44.0%), 2,4‐dinitrotolunene (32.6%), and 4‐nitrotoluene (28.8%). Superior quenching efficiencies of nitrophenolic compounds were ascribed to their strong binding affinity for (S1‐S3)‐Pyr due to the acidity of phenolic hydroxyl units. Besides, quenching ratios of S1‐Pyr , S2‐Pyr , and S3‐Pyr were measured to be very close to each other. Thus, (S1‐S3)‐Pyr are considered to be highly selective and sensitive fluorescence probes for phenolic nitroaromatic compounds. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46310.     

Surface‐confined electropolymerization of pyronin Y in the graphene composite paper structure for the amperometric determination of dopamine

Surface‐confined electropolymerization allowed us to easily prepare homogeneous polymer composite paper structures. The fabrication of freestanding graphene (Gr)‐based composite electrodes is very important for many modular approaches in electrochemical applications, such as fuel cells, supercapacitors, and sensors. A Gr composite paper electrode doped with polymeric films of pyronin Y was fabricated by two repetitive simple applications: vacuum filtration and surface‐confined electropolymerization. The characterization of this composite paper was done with scanning tunneling microscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, powder X‐ray diffraction spectroscopy, Raman spectroscopy, UV–visible absorption spectroscopy, four‐point probe conductivity measurement, cyclic voltammetry, and electrochemical impedance spectroscopy. The freestanding composite paper demonstrated good electrocatalytic activity for the electrooxidation of dopamine; this indicated that this composite paper could be used for the amperometric quantification of dopamine in real samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45139.     

Poly(methyl vinyl ether‐alt‐maleic anhydride) functionalized with 3‐aminophenylboronic acid: A new boronic acid polymer for sensing diols in neutral water

Amidation of poly(methyl vinyl ether‐alt‐maleic anhydride) with 3‐aminophenylboronic acid was used to prepare a new boronic acid polymer. The binding of catechol dye, Alizarin Red S to the polymer obtained resulted in getting a stable, colored sensor which was used to establish association constants with different diols in competitive assay. The binding of different diols was readily detected by color change and absorbance values measured at 450 nm were used to calculate the association constants. The polymer obtained formed high‐affinity complexes with ribonucleosides, particularly cytidine and uridine. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40778.     

Dye‐molecular‐imprinted polysiloxanes. II. Preparation,characterization, and recognition behavior

Microsphere silica (AMS) was prepared by the sol–gel method and used for the synthesis of dye‐molecular‐imprinted polysiloxanes. These were prepared by the cohydrolysis and polycondensation of the AMS with functional organosilicone monomers (N‐phenylaminomethyl triethoxysilane, 3‐aminopropyl triethoxysilane, and 4‐aza‐6‐aminohexyl triethoxysilane) in the presence of a template molecule of disperse red (or disperse blue or water‐soluble dye) followed by the removal of the template molecule. The molecular‐imprinting and nonimprinting polysiloxanes were characterized by elemental analysis, diffuse‐reflectance Fourier transform infrared spectroscopy, and scanning electron microscopy. Their adsorption behavior toward the template molecule and nontemplate molecule was investigated. The molecular‐imprinting polysiloxane exhibited higher selective recognition properties toward the template molecule than the nonimprinting polysiloxane. In the experimental conditions, their adsorption isotherms were a good fit with the Langmuir model. The distribution coefficient value of water‐soluble‐dye‐imprinted polysiloxane was the highest among the three imprinting polysiloxanes under the experimental conditions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 637–643, 2004     

Highly efficient adsorbent for organic dyes based on a temperature‐ and pH‐responsive multiblock polymer

The self‐assembly behavior of amphiphilic block copolymers in selective solutions has many applications in environmentally responsive polymer materials. In this article, we report on a new amphiphilic, temperature and pH dual‐responsive poly[2‐dimethylaminoethyl methacrylate‐co‐(methyl methacrylate)]‐b‐poly[poly(ethylene glycol) methacrylate] [P(DMAEMA‐co‐MMA)‐b‐PPEGMA], which was synthesized via reversible addition–fragmentation chain‐transfer polymerization. The structure, self‐assembly behaviors, and process of organic dye adsorption were characterized by ¹H‐NMR, ultraviolet–visible absorbance spectroscopy, and DLS measurements. P(DMAEMA‐co‐MMA)‐b‐PPEGMA was proven to be an outstanding adsorbent with excellent reversibility. Methyl red was released from the micelles as the pH value of the solution was adjusted to 4, and it could also be encapsulated again when the pH value was adjusted to 7.4 because of the sensitive pH‐responsive ability. It is promising that the triblock polymer had a positive effect on dye adsorption for environmental protection. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46626.     

Film formation from pigmented latex systems: Drying kinetics and bulk morphologies of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) blend films

The drying kinetics and bulk morphology of pigmented latex films obtained from poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex particles functionalized with carboxyl groups and ground calcium carbonate blends were studied. Latex/pigment blends with higher carboxyl group coverage on the latex particle surfaces dried faster than films with few or no carboxyl groups present. The latex/pigment dispersions also dried faster when there was more stabilizer present in the blend system because of the hydrophilic nature of the stabilizer. The net effect of increasing the pigment volume concentration in the blend system was to shorten the drying time. The bulk morphologies of the freeze‐fractured surfaces of the pigmented latex films were studied with scanning electron microscopy. Scanning electron microscopy analysis showed that increased surface coverage of carboxyl groups on the latex particles in the latex/pigment blends resulted in the formation of smaller pigment aggregates with a more uniform size distribution in the blend films. In addition, the use of smaller latex particles in the blends reduced the ground calcium carbonate pigment aggregate size in the resulting films. Scanning electron microscopy analysis also showed that when the initial stabilizer coverage on the latex particles was equal to 18%, smaller aggregates of ground calcium carbonate were distributed within the copolymer matrix of the blend films in comparison with the cases for which the initial stabilizer coverage on the latex particles was 8 or 36%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2267–2277, 2006     

Electroactive PVDF thin films fabricated via cooperative stretching process

Ferroelectric polymers have obtained much attention in low cost and flexible electronics. As one representative ferroelectric polymer, poly(vinylidene fluoride) (PVDF) has been comprehensively studied. Due to its complicated phase composition, fabrication of electroactive phases has been an open question especially for PVDF thin films deposited on solid substrates. Here cooperative stretching process is introduced for the fabrication of electroactive PVDF thin films. PVDF thin films are coated on stretchable poly(vinyl alcohol) substrates and mechanically stretched under optimized stretching parameters. Structural, spectral, and electrical measurements indicate that cooperative stretching process can effectively convert the nonpolar α phase to the electroactive β and γ phases companied by an enhancement of film crystallinity. Stretched PVDF films present a reverse piezoelectric coefficient of ?37 pm/V, comparable with the results from films fabricated by the other techniques. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46324.     

Functional silk fabric for detection and absorption of Zn(II)

Two reactive dyes (P1 and P2) based on salicyladehyde‐4‐amino‐benzoylhydrazone, which show high sensitivity and selectivity in sensing Zn²⁺, were synthesized and used to modify nonwoven silk fabrics. The prepared silk fabric was then characterized by IR, UV‐Vis, and fluorescence measurements. The results showed that reactive dyes were chemically reacted with silk fibers, rather than physical absorption. Moreover, compared with raw silk fabric, functional silk fabric was bestowed the properties of Zn²⁺ detection and improved absorption capacity of Zn²⁺. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43952.     

One‐pot preparation of multicolor polymeric nanoparticles with high brightness by single wavelength excitation

Fluorescent nanoparticles with multiplex distinct emission signatures and high brightness by a single wavelength excitation are substantially needed in multiplex bioassays and imaging. In this study, we synthesized fluorescent polymeric nanoparticles incorporated with three polymerizable organic dyes via a one‐pot miniemulsion. By altering the doping ratio of three tandem dyes, the nanoparticles display abundant multiple fluorescence such as blue, cyan, green, orange, pink, red etc., together with distinguishable emission signatures under a single wavelength excitation, which were arising from the effective fluorescence resonance energy transfer (FRET) between the three energy‐matched dyes. Meanwhile, a large Stokes shift (up to 250 nm) can be generated by taking place multiple FRET cascade mechanism between donor and acceptor fluorophores in nanoparticles, which also suggests broad applications in biological labeling and imaging. Moreover, these nanoparticles are uniform in size, highly bright, excellently photostable, and shown prominent longterm stability. Overall, the novel multicolor fluorescent polymeric nanoparticles augur well for their potential applications in multiplexed bioanalysis and emitting displays. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41492.     

The adsorption behaviors of the multiple stimulus‐responsive poly(ethylene glycol)‐based hydrogels for removal of RhB dye

In this article, the multiple stimulus‐responsive organic/inorganic hybrid hydrogels by combining poly(2‐(2‐methoxyethoxy) ethyl methacrylate‐co‐oligo (ethylene glycol) methacrylate‐co‐acrylic acid) (PMOA) hydrogel with magnetic attapulgite/Fe₃O₄ (AT‐Fe₃O₄) nanoparticles were applied to the removal of Rhodamine B (RhB) dye from wastewater. The adsorption of RhB by the hydrogels was carried out under different external environmental, such as pH, temperature and magnetic‐field. The results showed that the hydrogels still possessed temperature, pH and magnetic‐field sensitivity during the adsorption process, which indicated that the adsorption could be controlled by the hydrogels responsive. The dye adsorption had a significant increment at 30°C and the removal of RhB could reach to over 95%. Besides, the low pH values were also favorable for the RhB adsorption, the removal was over 90% at pH = 4.56. Kinetic studies showed that the pseudo‐second order kinetic model well fitted the experimental data. The rate constant of adsorption was 0.0379 g/mg min. Langmuir and Freundlich isotherm models were applied to the equilibrium adsorption for describing the interaction between sorbent and adsorbate. The maximum K_L and K_F were 2.23 (L/g) and 0.87 (mg/g) at 30°C, respectively. Under the external magnetic‐field, the adsorption rate significantly increased within 250 min and the hydrogels could be separated easily from wastewater. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42244.     

Influence of chitosan posttreatment parameters on the fixation of pigment‐based inks on ink‐jet‐printed cotton fabrics

Cotton fabrics were digitally printed with pigment‐based black ink with an HP Desk‐Jet 880C printer. These ink‐jet‐printed fabrics were posttreated with chitosan samples for the fixation of the pigment‐based ink on the cotton. The influence of various parameters, including the molecular weight (MW), application method (pad–dry–cure vs pad–batch), concentration, and pH, on the degree of fixation (DF) of the pigment‐based inks was examined. The chitosan‐posttreated cotton samples were evaluated for their color strength, DF, color difference, and whiteness index values and their colorfastness properties. Chitosan samples with MWs of 150,000 and greater than 375,000 showed 100% (complete) fixation of the pigment‐based inks on the cotton fabrics. DF drastically decreased in the chitosan with an MW of less than 5000. Both the pad–dry–cure and pad–batch methods were found to be suitable for chitosan application onto ink‐jet‐printed fabrics. Chitosan with an MW of 150,000 showed 100% fixation at concentrations ranging from 0.3 to 1%. A further decrease in the concentration significantly decreased the fixation. High fixation values were achieved at acidic pH, whereas a neutral to alkaline pH resulted in poor fixation. The colorfastness properties for each parameter studied are also discussed. The posttreatment of the digitally printed cotton with chitosan was found to be very effective in fixing the pigment‐based inks. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Chloro‐Functionalized Photo‐crosslinking BODIPY for Glutathione Sensing and Subcellular Trafficking

Glutathione (GSH) is one of major antioxidants inside cells that regulates oxidoreduction homeostasis. Recently, there have been extensive efforts to visualize GSH in live cells, but most of the probes available today are simple detection sensors and do not provide details of cellular localization. A new fluorescent probe (pcBD2‐Cl), which is cell permeable and selectively reacts with GSH in situ, has been developed. The in situ GSH‐labeled probe (pcBD2–GSH) exhibited quenches fluorescence, but subsequent binding to cellular abundant glutathione S‐transferase (GST) recovers the fluorescence intensity, which makes it possible to image the GSH–GST complex in live cells. Interactions between probe and GST were confirmed by means of photo‐crosslinking under intact live‐cell conditions. Interestingly, isomers of chloro‐functionalized 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) compounds behaved very distinctively inside the cells. Following co‐staining imaging with MitoTracker and mitochondria fractionation upon lipopolysaccharide‐mediated reactive oxygen species induction experiments showed that pcBD2–GSH accumulated in mitochondria. This is the first example of a live‐cell imaging probe to visualize translocation of GSH from the cytosol to mitochondria.     

Effect of mechanical treatments on orientation behavior and spectral properties of azoderivative dyes incorporated in poly(vinyl alcohol) films

Various azoderivative dyes were incorporated in uncolored poly(vinyl alcohol) (PVOH). One type of film was obtained by drying the layer of solution cast on glass plate. The other type was obtained by rubbing the PVOH layer before complete drying. Linear birefringence and dichroism of dyed polymer films were investigated as a function of stretching degree. An increase in the linear birefringence was found with increasing stretching degree for both uncolored and colored films. Dichroism of the PVOH films depends on the dye chemical structure and also on the stretching degree of both non-rubbed and rubbed and dyed PVOH samples. Molecular modeling was used to examine interactions occurring between PVOH and the embedded dye molecule. These stretching degree dependencies were approximated mathematically, which was used to describe the behavior of some components of interference filters.     

Disposable potentiometric citrate sensor based on polypyrrole‐doped films for indirect determination of sildenafil in pharmaceuticals formulations

A new sensitive and selective disposable potentiometric sensor based on polypyrrole (PPy) films for determination of sildenafil citrate (SC) was proposed. The pyrrole polymerization was performed in presence of citrate ions under galvanostatic conditions which resulted in a membrane of PPy doped with citrate anion at graphite pencil electrode surface. Experimental conditions (e.g., pH and conditioning time) and instrumental parameters (e.g., current density and electrical charge) were evaluated in order to reach the best potentiometric response for the proposed sensor. Under optimized conditions, the device presented a linear dynamic range (LDR) for citrate ions concentrations varying from 0.034 to 1.7 mmol L^?1 with a Nernstian slope of 57.2 mV dec^?1 and a limit of detection (LOD) of 30 µmol L^?1. The developed potentiometric sensor was applied for sildenafil citrate (SC) determination (pharmaceutical formulations) and results compared with an official spectrophotometric method indicating a good agreement for a confidence level of 95%. Effect of concomitants species on the potentiometric response of the proposed device and morphologic characterization using microscopy of atomic force (AFM) were realized. The surface roughness of PPy films (synthesized in citrate solution and chloride) showed poorly affected by changing the doping anion, probably because the polypyrrole nodules grow three‐dimensionally simultaneously. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43762.     

Pulsed Laser Deposition of zeolitic thin films: Novel structures for molecular recognition

Pulsed Laser Deposition is used to deposit zeolitic films onto a substrate. Using this technique, thin films are formed using both mordenite and faujasite targets. The target application for the films was the development of gas-selective sensors. These films are comprised of small crystallites embedded in an amorphous matrix. The amorphous material is microporous having pore sizes on the order of those in the parent zeolites. These pores are oriented perpendicular to the substrate. Pore orientation coupled with the high porosity provides a thin film with a potential for high gas throughputs. Quartz crystal microbalances coated with the material have been tested for gas uptake and have shown to discriminate between isomers of small molecules. Beyond sensors, the zeolitic films may hold promise for such applications as membranes.     

Coloration properties and chemo‐rheological characterization of a dioxazine pigment‐based monodispersed masterbatch

A dioxazine‐based color pigment was added to a commercial polyamide 6 (PA6) through an extrusion process, in order to prepare monoconcentrated violet masterbatches through different production set‐up. A detailed characterization of the resulting materials was carried out in order to find the best processing parameters combination to optimize pigment dispersion and to reduce the clogging power. The preparation of masterbatches with repeated extrusions markedly reduced the filter pressure value and increased the Relative Color Strength, while filtration did not significantly influence pigment dispersion. Rheological measurements and end‐groups analysis were conducted on the same materials with the aim to evaluate their thermal degradation resistance, and the thermal stability of the compounds was retained even upon three extrusions. Therefore, it can be concluded that a proper optimization of the process parameters could lead to an important reduction of the production waste, increasing the quality of the final product. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41452.     

Optimization of thermoelectric properties of metal‐oxide‐based polymer composites

Thermoelectric modules can be used for thermal energy harvesting. Common rigid thermoelectric stacks usually contain heavy metal alloys such as Bi₂Te₃. In order to substitute conventional materials and to reduce manufacturing costs, nontoxic, inexpensive and abundant materials using low‐cost processes are first choice. This study deals with polymer composites consisting of a polysiloxane matrix filled with thermoelectric Sn_0.85Sb_0.15O₂ particles in micrometer scale. Thin composite sheets have been prepared by doctor blade technique and the Seebeck coefficient, the electrical and thermal conductivity, and the porosity were measured. Platelet‐type particles, consisting of Sn_0.85Sb_0.15O₂‐coated insulating mica substrate and globular Sn_0.85Sb_0.15O₂ particles have been varied in size, coating thickness and were mixed with each other in different ratios. The filler content was varied in order to maximize the figure of merit, ZT, to 1.9 × 10^?5 ± 4 × 10^?6. Owing to their low raw material costs and the high degree of design freedom of polymer composites, one may use these materials in thermoelectric generators for remote low‐power demanding applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40038.     

Characteristic analysis of biaxially stretched PVDF thin films

By use of biaxial stretching process of poly(vinylidene fluoride) fabrication to gain high piezoelectricity is the focus in this article. The influence of different stretch ratio and temperature are investigated and compared to uniaxial stretching process. The Fourier transform infrared spectroscopy and X‐ray diffraction are used to observe the β‐phase fraction and the degree of crystallinity. The piezoelectric coefficients (d₃₃, d₃₁) and the sensitivity are also measured. All the above characteristic examinations show the same consequences that equi‐biaxial stretching process employed with same stretch ratio in both axial directions of poly(vinylidene fluoride) fabrication is the focus in this article. And heating temperature would have adequate piezoelectricity approximate to uniaxial stretching. In observation of surface morphology by using scanning electron microscopy, uniformity in biaxial direction is gained. However, biaxial stretching with higher stretch ratio of R = 4 × 4 would produce porosity and crack. Via atomic force microscopy, biaxial stretching with higher stretch ratio attains better surface chain orientation and smoothness. To sum up, the biaxial stretching approach has the advantage of low stretch ratio requirement to preserve good fabrication quality. Set up with stretch ratio in‐between R = 3 × 3 and R = 4 × 4 at 80 °C is suggested to use in biaxial stretching. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46677.