Luminescent Poly Research Articles

Ultraviolet encryption information storage using hydrophobic poly(ε-caprolactone)/carbon quantum dot composite film

Luminescent poly(ε-caprolactone)/nitrogen-doped carbon quantum dots (PCL/N-CQDs) film with the function of information protection and encryption was realized based on the fluorescent N-CQDs. The N-CQDs were synthesized from citric acid with urea as a dopant for the enhancement of fluorescent properties. The facilely prepared composite film retained the hydrophobic nature of PCL and achieved the enhanced mechanical property. The appropriate crystallization temperature and degree of crystallinity of PCL provide the film with opaque characteristics at room temperature, rendering it an ideal carrier for carrying information. The information encryption and decryption are achieved through ionoprinting technique, exploiting the ability of Fe3+ ions to quench the fluorescence of N-CQDs, allowing for the encryption of designed information on the film’s surface. With its opaque, hydrophobic, and photoluminescent properties, the PCL/N-CQDs composite film holds significant promise for applications in information encryption.

White-light clusteroluminescence of poly(β-hydroxyvinyl N-substituted carbamate)s via through-space interactions

White-light-emitting polymers have attracted considerable attention in the fields of solid-state lighting and flexible displays. However, achieving white light emission from single-component polymers, particularly in clusteroluminescence (CL) polymers, remains a significant challenge. Herein, we synthesize three non-conjugated luminescent poly(β-hydroxyvinyl N-substituted carbamate)s (PHNCs): PHNCs-C with steric cyclohexyl groups, PHNCs-E with side hydroxyethyl groups, and PHNCs-H with flexible n-hexyl carbon chains. All PHNCs show excitation-independent emission, which transitions to excitation-dependent emission as the excitation wavelengths increase. It is proposed that these emissions originate from the π*→n transition of carbamate in hydroxyurethane and CL of hydroxyurethane, respectively. PHNCs-C exhibits the strongest CL and possesses the highest quantum yield (17.9 %) in solution, a performance that surpasses both PHNCs-E and PHNCs-H. This finding implies that a rigid structure can enhance and stabilize the through-space interactions (TSIs) of hydroxyurethane groups, resulting in a wide cluster-size distribution and white-light emission. Theoretical calculations corroborate these experimental results, further revealing that TSIs occur between the oxygen atoms of hydroxyurethane groups, namely, through-space n-n interactions of oxygen atoms. This work not only provides valuable insights into the nature of CL and TSIs, but also offers a novel approach to preparing single-component white-light-emitting CL polymers.

Open Linear Polymer Host-Guest Interactions Sensed by Luminescent Silver Nanodots.

The selectivity of the linear polymer chain toward its binding moieties has been considered negligible; thus, a clear demonstration showing the best-fit binding of a linear polymer to its guest counterpart is still unknown. Luminescent poly(acrylic acid) (PAA)-stabilized silver nanodots (PAA-AgNDs) have been applied as a turn-on sensor to monitor the interaction between the PAA chain and its binding cations. The binding of cations ions to the PAA chain may cross-link the linear PAA chain via coordination with carboxylate, which increases the rigidity of the polymer chain, retards the nonradiative decay of PAA-AgNDs, and consequently enhances the emission of silver nanodots while inducing a blue-shift of its emission spectrum. For the first time, we have demonstrated that a linear polymer chain can act as an open host to selectively bind to its best-matching cations. Specifically, among Group 2 cations (Mg2+, Ca2+, Sr2+, Ba2+), calcium ions show the strongest bonding to the PAA polymer chain. Our research suggests that, with extra rigidity, the polymer improves its chemical stability as calcium ions cross-linked the linear polymer. Meanwhile, it has also been demonstrated that luminescent silver nanodots can be excellent probes for the detection of polymer activities with straightforward and simple visualization methods.

Process intensified synthesis of luminescent poly(9,9-dioctylfluorene-alt-benzothiadiazole) and polyvinyl alcohol based shape memory polymeric nanocomposite sensors toward cold chain logistics information monitoring

Luminescent shape memory polymeric nanocomposite sensors prepared using poly(9,9-dioctylfluorene-alt-benzothiadiazole) and polyvinyl alcohol for cold chain logistics information monitoring.

Intrinsically elastic and self-healing luminescent polyisoprene copolymers formed via covalent bonding and hydrogen bonding design

Although development of soft and stretchable materials exhibiting semiconducting functions, such as luminescent or electronic properties, has received growing interest, development of intrinsically self-healing semiconducting materials remains a challenge. In this study, covalent and hydrogen-bonding architectures were used to construct polyisoprene (PI)-based rubber containing luminescent poly[2,7-(9,9-dioctylfluorene)] (PF), and the material exhibited elastic behavior and spontaneous healing. The first demonstration of an engineered hard–soft multiphase, well-dispersed polymer thin film was conducted, wherein the soft phase backbone containing dynamic hydrogen bonds and rubber-like moieties imparted resistance against damage due to repeated stretching, while the hard phase comprising aggregates of rigid PF branches imparted luminescence. Under intense mechanical stress, both the bulk and thin-film states of the crosslinked PF0.16-co-PI0.37-co-PBACO0.47 impressively presented typical elastic performance. Owing to the dynamic nature of the hydrogen bonds within the crosslinked polyisoprene copolymer, the bulk and thin film states exhibited good self-healing and an 83% recovery efficiency following treatment for 24 h at room temperature. This strategy is potentially useful for fabrication of fully flexible electronics with good mechanical properties and many functionalities.

Luminescent Poly(vinylidene fluoride)‐Based Inks for Anticounterfeiting Applications

Counterfeiting is a global ever‐growing problem of immense magnitude that represents a menace to security, economy, and health at a worldwide level. Herein, a new luminescent security ink composed of poly(vinylidene fluoride) (PVDF) and the home‐made ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetra(thenoyltrifluoroacetonato)europate(III) ([Bmim][Eu(tta)4]) is reported. The optimized PVDF/[Bmim][Eu(tta)4] composite is processed by the doctor blade method as a micrometer‐thick film invisible under white light, with porous texture. The material exhibits high thermal stability, high chemical stability (inertness with respect to ethanol), high photostability, and intense red emission when excited with long UV radiation (365 nm) with a maximum quantum yield value of 0.10 ± 0.01. A test of the PVDF/[Bmim][Eu(tta)4] ink screen‐printed on a medical N95 protection mask performed under irradiation with white light and with a commercial 365 nm LED demonstrates its suitability to combat fraud. The exciting possibilities offered by PVDF/luminescent IL pair in terms of chemical modification of PVDF (copolymerization or functionalization) and IL (cation type/lanthanide ion/ligand type) for the tuning of the ink properties allow envisaging the production of tailor‐made tri‐ or biluminescent security inks, for authentication purposes.

Effect of Polymer Nano- and Microparticles on Calcium Carbonate Crystallization.

Molecular and macromolecular templates are known to affect the shape, size, and polymorph selectivity on the biomineralization of calcium carbonate (CaCO3). Micro- and nanoparticles of common polymers present in the environment are beginning to show toxicity in living organisms. In this study, the role of plastic nanoparticles in the biomineralization of CaCO3 is explored to understand the ecological impact of plastic pollution. As a model study, luminescent poly(methyl methacrylate) nanoparticles (PMMA-NPs) were prepared using the nanoprecipitation method, fully characterized, and used for the mineralization experiments to understand their influence on nucleation, morphology, and polymorph selectivity of CaCO3 crystals. The PMMA-NPs induced calcite crystal nucleation with spherical morphologies at high concentrations. Microplastic particles collected from a commercial face scrub were also used for CaCO3 nucleation to observe the nucleation of calcite crystals on the particle surface. Microscopic, spectroscopic, and X-ray diffraction data were used to characterize and identify the nucleated crystals. The data presented in this paper add more information on the impact of microplastics on the marine environment.

Novel AIE luminescent tetraphenylethene-doped poly (lactic acid) composites for fused deposition modeling and their application in fluorescent analysis of 3D printed products

Luminescent 3D printing materials have attracted many attentions due to their promising applications of luminescent inks, hydrogels and microstructures. However, no reports have shown the priority of their fluorescence for detection of the quality of 3D printing products. In this work, novel luminescent poly (lactic acid) (PLA) composite filaments with typical aggregation-induced emission (AIE) building block (tetraphenylethene, TPE) for 3D printing have been successfully developed, by simple solution premixing and melt extrusion methods. It was found that TPE uniformly dispersed in the PLA matrix and significantly increased the crystallinity of PLA, which not only maintained the good thermal property but also improved the mechanical properties of TPE/PLA composites. Notably, the composite filaments emitted ultra-bright blue light under UV lamp, and the fluorescence intensity increased as the content of TPE increased. Finally, several brightly luminescent exquisite articles could be manufactured by a single-nozzle 3D printer with these new fluorescent filaments. Most interestingly, a thin layer of 0.4 mm TPE/PLA was implanted in the strip-shaped specimens by a dual-nozzle printer, which could be used as a very sensitively fluorescent visual inspection of the quality of 3D printing products, including the degree of bending damage and their small defects. Therefore, the development of novel luminescent TPE/PLA composites combined with 3D printing technology in this work provides a unique opportunity for the design and application of luminescent 3D printing materials.

Catalyst-Free Multicomponent Tandem Polymerizations of Alkyne and Amines toward Nontraditional Intrinsic Luminescent Poly(aminomaleimide)s

The development of a facile and efficient polymerization method to prepare polymers with unique nontraditional intrinsic luminescent (NTIL) properties is of vital importance and highly desired. In ...

Helix-Sense-Selective Synthesis of Right- and Left-Handed Helical Luminescent Poly(diphenylacetylene)s with Memory of the Macromolecular Helicity and Their Helical Structures.

Symmetrically substituted poly(diphenylacetylene) (PDPA) bearing carboxy pendants was found to fold into a one-handed helix upon thermal annealing with nonracemic amines in water accompanied by chiral amplification of the helicity. The induced right- or left-handed helical PDPA was retained (memorized) after complete removal of the chiral amines, thus producing a one-handed helical circularly polarized luminescent PDPA in a helix-sense-selective manner. The helical PDPA with static helicity memory is tolerant toward modification of carboxy pendants, providing functional PDPAs with an optical activity solely due to macromolecular helicity. The PDPA and its derivatives before and after the one-handed helicity induction and its subsequent memory of the helicity exhibited well-resolved very simple 1H and 13C NMR and Raman spectra whose spectral patterns are virtually identical independent of the helical sense bias. On the basis of the 1H and 13C NMR, IR, Raman, and vibrational and electronic circular dichroism spectral measurement results combined with theoretical calculations, the key structural features (cis or trans and cisoid or transoid) of the PDPA as well as its helix inversion barrier and absolute handedness (right- or left-handed helix) and helix-sense excess of the one-handed helical PDPA and its derivatives with static helicity memory were determined. As a result, almost complete right- and left-handed helical cis-transoidal PDPAs with 98% helix-sense excess were successfully obtained using noncovalent helicity induction and memory strategy.

Controlling the fluorescence intensity of luminescent thin films by photoisomerization of azo dyes

Luminescent poly p-phenylene vinylene (PPV) thin films were produced by the layer-by-layer technique, using organic dyes as the counter ion. It was observed that, when dyes with azo groups are incorporated in the PPV polymeric chains, the fluorescence intensity can be substantially increased by the photo-irradiation of the film with a linearly polarized laser beam. The data show that such emission enhancement is due to the alignment of the dye molecules caused by the photo-isomerization of the azo groups. This process leads to an absorbance of the dyes that is dependent both of the photo-irradiation dose and the polarization direction of the irradiation source, which affects the fluorescence emitted by the polymer. Thus, the incorporation of azo dyes can be used to modulate the fluorescence response of polymeric thin films.

Luminescent poly(dendrimer)s for the detection of explosives

Poly(dendrimer)s have a larger response compared to their corresponding monomers for the detection of trace quantities of nitro-based explosives.

The effect of the phenylene linkage in poly(fluorene-alt-phenylene)s on the thermodynamics and kinetics of nitroaromatic and nitroaliphatic sensing

The preparation, photophysical characterization and sensing of a series of highly luminescent poly(fluorene-alt-phenylene)s (PFP) were studied. These PFP polymers varied the phenylene linkage in the 1,4 (PFP-p), 1,3 (PFP-m) and 1,2 (PFP-o) positions. The photoluminescence of these polymers ranged from ultraviolet to blue in color in both solution and film states by simply varying the linkage of the phenylene moiety. Photon Electron Spectroscopy in Air (PESA) revealed that the change in the emission was primarily attributed to the difference of the electron affinity of the polymer. Stern-Volmer quenching studies indicated that these poly(fluorene-alt-phenylene) polymers are highly sensitive towards nitroaromatic materials in solution, particularly in comparison to the reference poly(9,9-di-n-hexylflourene) (PDHF). These PFP polymers were found to be four to ten times more sensitive towards dinitrobenzene as compared to PDHF. In addition, PFP-o displayed the highest polymer-based Stern-Volmer quenching towards the taggant DMNB. The solid-state fluorescence quenching of the PFP-p and PFP-m films using DMNB was enhanced (up to 71.5%) compared to the reference PDHF (59.6%) and was attributed to both thermodynamic and diffusion kinetic factors.

Yellow–green luminescent poly(vinyl alcohol) nanocomposite thick films as effective spectral manipulators

ABSTRACTHighly flexible and visibly transparent yellow–green fluorescent poly(vinyl alcohol) (PVA) based nanocomposite (NC) films with rubidium zincate (Rb2ZnO2) nano impregnates were developed through aqueous solution casting. The introduced rubidium zincate nanofillers impart UV shielding properties to PVA host, through UV to visible (fluorescent yellow–green) photon cutting. The rubidium zincate nanofiller impregnated PVA systems were also characterized for their structural, morphological, optical, and electrical behaviors by various analytical tools. The Fourier Transform Infrared (FTIR) and X‐ray diffraction (XRD) studies shed light on the changes in gross structural properties of PVA. WhileScanning Electron Microscopic (SEM) profiles support uniform filler dispersions, which aid high visible transparencies. Further, the UV–visible spectral measurements depict the changes in electronic band structure that validates novel fluorescent emission properties, established through fluorescent emission studies. The NC films show excellent visible transparency (72–84%), near hydrophobic surface wettabilities (ϴ = 82°–93°) and enhanced charge conduction, in addition to high flexibilities and UV photons induced fluorescent emission ( λEmi=585 nm). The yellow–green luminescent, Rb2ZnO2 nanofillers reinforced PVA NC films are effective spectral manipulators, which may be used as competent packaging materials for photonic display devices and to extend the short wavelength limit of solar cells. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46854.

Photoinitiated Interfacial Thiol-ene Click Chemistry for the Synthesis of Luminescent Hollow Polymer Colloids by Synchronously Anchoring CdTe Nanocrystals

In this work, we report a facile strategy to anchor CdTe nanocrystals onto synchronously synthesized polymer for the fabrication of luminescent hollow poly(3-methacryloxypropyltrimethoxysilane) (PMPTS)/CdTe composite colloids. Firstly, glutathione-coated CdTe nanocrystals with green fluorescence were synthesized in an aqueous solution. Dithiothreitol was then introduced into the solution as co-ligand and cross-linker to bridge CdTe and prospective polymer. Subsequently, MPTS monomers and light initiator in toluene solution were added into the CdTe aqueous solution under sonication to form a semi-stable emulsion. Finally, the emulsion was light irradiated to prepare PMPTS colloids and simultaneously graft CdTe nanocrystals onto these colloids through thiol-ene click chemistry. This facile route allows the polymer synthesis and its functionalization with inorganic nanoparticles in one step, potentially leading to practical applications for building diverse hybrid structures.

Dispersion of upconverting nanostructures of CePO4 using rod and semi-spherical morphologies into transparent PMMA/PU IPNs by the sequential route

Upconverting luminescent poly (methylmethacrylate) (PMMA)/poly (urethane) (PU) interpenetrating polymer network (IPN) nanohybrids were prepared using a sequential polymerisation incorporating different wt.% of cerium phosphate (CePO4) nanoparticles. The effect of miscibility/compatibility of the different PMMA/PU ratios, the addition and dispersion of rod and semi-spherical nanostructures in as well as the performance of selected IPNs under accelerated aging were studied using morphological, emission, thermal and mechanical studies. Structural studies revealed that there were physical interactions between CO groups and CePO4 in PMMA/PU IPNs. The addition of a higher wt.% of nanostructures was found to decrease the transparency of the IPNs. Resulting PMMA/PU/CePO4 IPN nanohybrids are photoluminescent under UV-light, supporting the prolongate of lifetime while maintaining the mechanical properties after being subjected to accelerated weathering. The addition of semi-spherical particles resulted in a more stable materials after accelerated weathering than nanorods.

Two-Step Synthesis and Surface Modification of CaZnOS:Mn2+ Phosphors and the Fabrication of a Luminescent Poly(dimethylsiloxane) Film.

The CaZnOS:Mn2+ (CZOSM) phosphor has been extensively studied for its excellent optical performance, with a typical red emission band peaking at about 580 nm ascribed to the 4T1(4G)-6A1(6S) transition of Mn2+. Herein the CZOSM phosphor was synthesized by a novel two-step method accompanied by control of the morphology of the precursor in the first step followed by sintering in the second step, which demonstrated improved emission intensity and uniform morphology simultaneously compared to those obtained by the traditional solid-state reaction route. Thus, uniform ZnS:Mn2+ particles could be obtained by a hydrothermal method, and then a Ca(OH)2 shell was coated onto the ZnS:Mn2+ particles via a precipitation reaction. After that, these mixtures were sintered at the optimum temperature 800 °C in an argon atmosphere to prepare the CZOSM particles. Oleic acid (OA) was further used to transfer the hydrophilic CZOSM phosphors to hydrophobic ones. Finally, luminescent poly(dimethylsiloxane) (PDMS) films were fabricated by using the hydrophobic CZOSM@OA powders, and their optical performance and flexibility were evaluated. Our results provide insight into the synthesis of hydrophobic phosphor particles used in luminescent PDMS films and help to unravel their potential application for flexible optical devices.

Large‐area flexible, transparent, and highly luminescent films containing lanthanide (III) complex‐doped ionic liquids for efficiency enhancement of silicon‐based heterojunction solar cell

ABSTRACTIonic liquid (IL)‐based lanthanide luminescent materials with luminescent downshifting properties are beneficial for enhancing the photovoltaic energy conversion efficiency (ηpv) of silicon‐based solar cells. Herein, novel lanthanide (III) complex‐doped ILs have been successfully prepared by simply dissolving the complex Ln(pybox)3 (Ln = Eu or Tb, pybox = 2,6‐bis[(4R)‐4‐phenyl‐2‐oxazolinyl]pyridine) into a bidentate organophosphine functionalized IL (1,3‐bis‐[3‐(diphenylphosphinyl)propyl]imidazolebis (trifluoromethylsulfonyl)imide), showing improved luminescence efficiency attributed to the coordination of ILs with Ln3+ ions and thus occurrence of the energy transfer from ILs to Ln3+ ions and very high absolute quantum efficiency (up to 97.22%). Large area (17 × 17 cm2) flexible, transparent, and luminescent poly(methyl methacrylate) thin films were prepared through a simple drop‐casting method and were applied as luminescent downshifting coatings to the silicon‐based heterojunction solar cells (active area: 235 cm2). In the best case using the Tb3+‐containing film, the ηpv of the solar cell increases from 16.676 to 16.774%.

Synthesis and cell imaging applications of amphiphilic AIE-active poly(amino acid)s

The poly(amino acid)s based biomaterials have attracted great research attention over the past few decades because of their biocompatibility, biodegradability and well designability. Although much progress has achieved in the synthesis and biomedical applications of poly(amino acid)s, the synthesis of luminescent poly(amino acid)s has been rarely reported. In this work, novel amphiphilic luminescent poly(amino acid)s with aggregation-induced emission (AIE) feature have been synthesized by a new approach of controlling N-carboxy anhydride (NCA) ring-opening polymerization, in which hydrophobic 2-(4-aminophenyl)-3-(10-hexadecyl-4H-phenothiazin-3-yl)acrylonitrile (Phe-NH2) with AIE feature was used as initiator and hydrophilic oligomeric glycol functionalized glutamate (OEG-glu) NCA was acted as monomer. The successful synthesis of final Phe-OEG-Pglu polymers was confirmed by different characterization techniques. Phe-OEG-Pglu polymers possess amphiphilic properties and can self-assemble into luminescent polymeric nanoparticles (LPNs). Based on cellular imaging experiments, we demonstrated that Phe-OEG-Pglu LPNs have great potential for bio-imaging applications due to their attractive properties including strong fluorescence intensity, great water dispersibility, excellent biocompatibility and high cellular uptake efficiency.

Luminescent Poly(vinyl alcohol)/Carbon Quantum Dots Composites with Tunable Water-Induced Shape Memory Behavior in Different pH and Temperature Environments.

Luminescent water-induced shape memory polymer (SMP) composites with tunable shape recovery rate are developed by blending poly(vinyl alcohol) (PVA) and carbon quantum dots (CQDs). The oxygen and active hydrogen-rich CQDs can serve as extra physical cross-linking points in PVA via strong hydrogen bonding interaction, which largely improves the shape memory performances of PVA. At room temperature, water can successfully actuate the shape recovery of deformed PVA/CQDs composite. It is demonstrated that this water-induced shape recovery is mainly attributed to the plasticizing effect of water and its competitive hydrogen bonding. Furthermore, a quantitative bending test suggests that the shape recovery time of this water-induced SMP is tunable by altering the environmental pH value and temperature, and a relatively large shape recovery time window (from 20 to 200 s) can be achieved. In addition, the introduction of CQDs endows the PVA/CQDs SMP composites with excellent luminescent property, which makes the shape change of SMP visible under UV light. It should be noted that the mild stimulus condition and tunable shape recovery performances make the luminescent visible PVA/CQDs SMP feasible for diverse biological applications in smart medical devices, stimuli-responsive drug-release, and intelligent sensors in vivo and in vitro.