Carbonized Polymer Dots Research Articles

Enhancing the mechanical and electrical conductivity of copper matrix composites through grafting carbonized polymer dots (CPD) onto carbon nanotube surfaces

Tailoring the structural design of reinforcement is an effective strategy to attain the homogeneous dispersion and robust interface bonding in carbon nanotubes reinforced copper (CNTs/Cu) composites. Herein, a novel zero-dimensional carbonized polymer dots (CPD) was synthesized and grafted onto the CNTs surfaces via a typical one-step hydrothermal method. The resultant reinforcement, CPD@CNTs, exhibited good dispersibility due to the abundant polar functional groups on CPD. Furthermore, the interface adhesion was also ameliorated by means of the in-situ formed Cu2O transient phase. The CPD@CNTs/Cu composite shows outstanding mechanical performances, the yield strength and tensile strength had increased to 269 MPa and 308 MPa, while maintained excellent ductility (43 %). Moreover, the electrical conductivity of the composite remains at a high level of 95.3 %IACS. Our findings suggest that adjusting the structural configuration of reinforcement is a feasible approach to optimize dispersion and interfacial structure.

Dual-Emission Carbonized Polymer Dots Combined with Metal Ions as a Single-Component Fluorescence Sensor Array for Pattern Recognition of Glycosaminoglycans

Dual-Emission Carbonized Polymer Dots Combined with Metal Ions as a Single-Component Fluorescence Sensor Array for Pattern Recognition of Glycosaminoglycans

Carbonized Polymer Dots Enhancing Interface Stability of LiNi0.8Co0.1Mn0.1O2 Cathodes

AbstractThe high energy density, low cost, and low toxicity of LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes has led to their large‐scale mass production. However, the poor interfacial stability between NCM811 and organic electrolytes impairs the long‐cycle performance of lithium ions batteries. In this study, carbonized polymer dots (CPDs) are successfully introduced onto the surface of NCM811 (NCM811@CPDs) via a simple physical mixing process. CPDs with rich surface oxygen functional groups form strong covalent bonds with transition metal (TM) ions at the NCM811 surface, distinctly restraining surface structure degradation, and transition metal ion dissolution. Furthermore, CPDs facilitate the formation of a compact and steady cathode electrolyte interface (CEI) layer during electrochemical cycling. As a result, the NCM811@1 wt% CPDs exhibit enhanced cycling performance with a capacity retention of 89.77% after 100 cycles at 0.5 C compared to 55.39% of the bare NCM811. This facile and effective surface decoration strategy provides valuable guidance for improving the stability and cycling performance of Ni‐rich cathodes.

Rapid and sensitive determination of histamine based on a fluorescent aptamer probe with analogue on carbonized polymer dots

Rapid and sensitive determination of histamine based on a fluorescent aptamer probe with analogue on carbonized polymer dots

Novel Dual-Emission Carbonized Polymer Dot-Based Ratiometric Fluorescence Probe for the Sensitive Detection of Tertiary Butylhydroquinone.

Tertiary butylhydroquinone (TBHQ), one of the most common antioxidants in many foods, has attracted widespread attention due to its potential risk to human health. In this work, an "on-off-on" ratiometric fluorescent probe was prepared using dual-emission carbonized polymer dots (d-CPDs), which can be used to detect TBHQ in edible oils. The ratiometric fluorescent sensing system consisted of blue fluorescent CPDs (b-CPDs) as the response signal and yellow fluorescent CPDs (y-CPDs) as the internal reference material. The blue fluorescence of b-CPDs was gradually quenched with increasing Fe3+ ion concentration, while the yellow fluorescence was essentially unaffected. Interestingly, TBHQ can restore the fluorescence intensity of b-CPDs. Meanwhile, the fluorescence mechanism of Fe3+ on b-CPDs was investigated by density functional theory, both after the addition of TBHQ, and CPDs were released and their fluorescence was restored due to the competitive reaction of TBHQ-Fe3+. Thus, the d-CPDs probe was able to detect Fe3+ accurately in an "on-off" manner and thus TBHQ in an "off-on" manner. At an optimal Fe3+ concentration, the ratiometric sensing system provided fine linearities for determining TBHQ in the range from 0.2 to 2 μM and an ingenious detection limit of 0.052 μM. The CPDs ratiometric fluorescent probe designed in this work may have a broader application in the rapid, susceptive, and low-cost determination of TBHQ in various foods.

Flexible Transparent Hydrophobic Coating Films with Excellent Scratch Resistance Using Si-Doped Carbonized Polymer Dots as Building Blocks.

Flexible transparent hydrophobic coating films with excellent scratch resistance have important applications in many fields, especially for optical materials. Herein, a hydrophobic composite coating film was prepared and used as a polymer film protective material by combining 3-glycidyloxypropyltrimethoxysilane (GPTMS)-modified Si-doped carbonized polymer dots (Si-CPDs) with mono-trimethoxysilyl-terminated poly(dimethyl siloxane) (PDMS). The Si-CPDs derived from tetramethyl disiloxane propylamine tetraacetic acid and multi-amino oligosiloxanes were successfully prepared via one-step hydrothermal method and then grafted by GPTMS to obtain modified Si-CPDs (mSi-CPDs). Among them, mSi-CPDs act as a matrix layer, and PDMS acts as a low-surface energy layer. Cross-linking the Si-O-Si network of the coating film was formed through sol-gel chemistry. Driven by the hydrophilic-hydrophobic effect, PDMS trends to aggregate at the film surface, thus avoiding the phase separation which can affect transparency. The highly cross-linked network and the presence of hard silica core provide a high hardness to stand the steel-wool scratch. Flexible polymer chains impart the coating film an outstanding bendability. Introduction of PDMS makes the coating film possess hydrophobicity and anti-graffiti function.

Circularly Polarized Room-Temperature Phosphorescence with an Ultrahigh Dissymmetry Factor from Carbonized Polymer Dots by Stacked Chiral Photonic Films.

Developing circularly polarized room-temperature phosphorescent (CPRTP) materials with a high dissymmetry factor (glum) and long afterglow is very attractive but highly challenging. Here, a CPRTP emission featuring ultrahigh glum value and desired visualization characteristic in a bilayer composite photonic film is achieved for the first time. In the constructed system, N and P co-doped carbonized polymer dots (NP-CPDs) are dispersed into polyvinyl alcohol (PVA) as the phosphorescent emitting layer, and helically structured cholesteric polymer films are used as selective reflective layers to convert the unpolarized emission of NP-CPDs into circularly polarized emission. On the basis of the modulation of the helical structure period of the cholesteric polymer, the bilayer composite film enables NP-CPDs to obtain a high glum value. Notably, the optimized photonic film emits CPRTP with glum as high as 1.09 and a green afterglow lasting above 8.0 s. Moreover, the composite photonic array films featuring information encryption characteristics are developed by modulating the liquid crystal phase of the cholesteric polymer film and the dot coating position of the NP-CPDs/PVA layer, thus expanding the application of CPRTP materials in cryptography and anti-counterfeiting.

Rational adjustment to interfacial interaction with carbonized polymer dots enabling efficient large-area perovskite light-emitting diodes

Film uniformity of solution-processed layers is the cornerstone of large-area perovskite light-emitting diodes, which is often determined by the ‘coffee-ring effect’. Here we demonstrate a second factor that cannot be ignored is the solid-liquid interface interaction between substrate and precursor and can be optimized to eliminate rings. A perovskite film with rings can be formed when cations dominate the solid-liquid interface interaction; whereas smooth and homogeneous perovskite emitting layers are generated when anions and anion groups dominate the interaction. This is due to the fact that the type of ions anchored to the substrate can determine how the subsequent film grows. This interfacial interaction is adjusted using carbonized polymer dots, who also orient the perovskite crystals and passivate their buried traps, enabling a 225 mm2 large-area perovskite light-emitting diode with a high efficiency of 20.2%.

Promising carbonized polymer dots for visually sequential sensing of Cu2+ and S2−

Carbonized polymer dots (CPDs) are formed by combining lignite, which primarily forms carbon cores, with polyvinylpyrrolidone, citric acid and tryptophan, which primarily produce short polymer chains and surface functional groups. These CPDs display a unique core–shell structure, excellent optical stability, superior fluorescence intensity, high quantum yield (QY) and outstanding biocompatibility allowing them to be well suited for application as fluorescent sensors. CPDs can be employed both as smart sensing systems for visual detection and absorption of Cu2+ and S2− through hydrogel sensors and as fluorescent inks for information security and anti-counterfeiting. More importantly, the paper-based platform and smartphone assistance enable visual real-time on-site quantification of Cu2+ and S2−, which offers an effective tool for fast and accurate Cu2+ and S2− identification and information encryption with high selectivity and sensitivity. In addition, with its good biocompatibility and low cytotoxicity, the CPDs have been successfully utilized for imaging Cu2+ and S2− in MG-63 cells, thus making a positive contribution to the analysis and imaging of the effects of Cu2+ and S2− in relevant biological processes and promoting better diagnosis and treatment of diseases.

Polythiophene Derivatives Carbonized Polymer Dots: Aggregation Induced Solid‐State Fluorescence Emission†

Comprehensive SummaryCurrently, solid‐state fluorescent carbonized polymer dots (CPDs) have attracted attention increasingly due to their applications for optoelectronic display. However, designing CPDs possessing solid‐state fluorescence and clarifying the fluorescence mechanism remain challenging. Herein, we initially synthesized a novel type of polythiophene derivatives CPDs, poly‐4,4’‐(thiophene‐3,4‐diyl)dibenzoic acid carbonized polymer dots (PDBA‐CPDs) with solid‐state fluorescence. Subsequently, the structural and optical characterization revealed that the solid‐state fluorescence originated from the aggregation induced emission of the CPDs. In brief, in aggregation state, the remaining polymer structure groups on the surface of the CPDs overlapped and weakened the non‐radiative transition, enhancing solid‐state fluorescence emission. Thirdly, three polythiophene‐derived CPDs were designed to further demonstrate the aggregation induced solid‐state fluorescence mechanism. Finally, owing to their unique properties of solid‐state fluorescence, the white LEDs (light emitting diodes) were fabricated with high color rendering index (CRI) of 82.7 and CIE coordinates of (0.37, 0.39) using commercial 460 nm chip. This work facilitates the development of CPDs’ solid‐state fluorescence mechanisms and advances the application of CPDs in the field of optoelectronics.

One-pot synthesis of nitrogen-doped carbonized polymer dots with tunable emission for multicolor light-emitting diodes

Carbonized polymer dots (CPDs) have highly potential application value in the field of optoelectronic devices due to their preferable stability, excellent optical properties and low cost. Here, the nitrogen-doped carbonized polymer dots (HNCDs) with self-quenching-resistant fluorescence were prepared via a simple solvothermal method with citric acid, urea and 2-hydroxyethyl methacrylate (HEMA) as raw materials. The structure and optical properties of the HNCDs have been explored in detail by various contrast experiments. The results show that HEMA form the poly(HEMA) to modify on the surface of carbonized core, which can overcome the quenching effect of carbonized core. The nitrogen doping is crucial for the red shift emission of solid-state HNCDs. Furthermore, the HNCDs exhibit concentration-dependent emission and excellent compatibility with silicone sol, which lead to their emission red shifted from blue to red with increasing concentration. The HNCDs were further applied to construct the light-emitting diodes (LEDs), and the multicolor LEDs ranging from blue to red can be prepared by simply varying the type of chips and adjusting the concentration of HNCDs in encapsulating material.

Fabrication of electron’s path based on carbonized polymer dots to accelerate photocatalytic hydrogen production kinetic for carbon nitride

Constructing efficient path for electron mobility is significant for increasing carrier separation and transport ability but a great challenge. Herein, a unique shell based on carbonized polymer dots (CPDs) is fabricated to serve as electron’s path for charge transfer from carbon nitrides (CN) to metal-based cocatalysts. This CPDs shell homogenously fixes each CPD on the catalyst surface through metal-N bonding, and possesses strong electron extraction ability by masterly controlling the pyridinic N structure. As a result, the obtained CN/MoP@CPDs-200 achieves an outstanding apparent quantum efficiency (9.4% at 450 nm), which is superior to CN/3 wt% Pt. Importantly, in-depth transient photo-induced voltage studies confirm the excellent charge extraction ability of CPDs shell, and thorough apparent kinetic analysis reveals that the photocatalytic hydrogen production process undergoes a Volmer-Heyrovsky mechanism that demonstrates the reduction reaction between photogenerated charges and water (H*+H2O+e-→H2↑+OH-), which is a critical missing investigation in photocatalytic studies for CPDs.

A facile rapid-response and on-site sensor for tetracycline detection in environmental water based on europium-doped carbonized polymer dots

With the increasing concerns about public safety and environmental protection, it is of great significance to establish a rapid and sensitive method to detect antibiotic residues in environmental samples. Herein, fluorescent carbonized polymer dots (CPDs) were synthesized and used for quantitative assay of tetracycline (TC) by chelating with europium ions (Eu3+). The green fluorescence of CPDs could be gradually quenched by TC via inner filter effect and static quenching mechanism, while the red emission of Eu3+ was remarkably enhanced through energy transfer and antenna effect. This ratiometric fluorescence Eu/CPDs-based sensor displayed a wide detection range of 0.05–56, 56–100 μM with a detection limit of 16.4 nM, and was triumphantly applied for TC analysis in water samples with high reliability and accuracy. Moreover, the polymeric structure in CPDs endowed the sensor with good long-term sensing stability up to 600 days. By integrating Eu/CPDs with portable capillary testing kit, a point-of-use device was constructed for facile determination of TC in river water samples with a short sample-to-answer analysis process in 2 min. Due to its easy operation, low-cost, and there is no pretreatment required, the capillary-based testing kit provides a new strategy for on-site and rapid detection of antibiotics in various environmental water samples.

Room temperature phosphorescence based on nitrogen-phosphorus co-doped carbonized polymer dots for information encryption

Carbonized polymer dots (CPDs) are proposed as a novel room temperature phosphorescence (RTP) materials that widely used in optoelectronic devices, bioimaging, especially in the field of information encryption and anti-counterfeiting due to their unique optical properties. However, achieving RTP emission under matrix-free conditions requires reasonable structural design to prevent the quenching of triplet excitons, which is very challenging. Herein, we proposed a facile, rapid and effective strategy to prepare matrix-free nitrogen and phosphorus co-doped CPDs (named Arg-CPDs) via microwave assisted heating treatment of arginine (Arg) and phosphoric acid. The Arg-CPDs exhibit bright blue fluorescence in aqueous solution and yellow green RTP emission in solid state, and the RTP emission is visible to the naked eye for about 4 s after switching-off the UV lamp. The phosphorescence lifetime of Arg-CPDs was 149 ms and 667 ms in ambient conditions and low temperature (77 K), respectively, which shown that the typical phosphorescent properties. Moreover, potential applications of the Arg-CPDs in the fields of information protection and encryption are demonstrated. This study provides a facile strategy for the preparation of matrix-free CPDs-based RTP materials toward the information security and their successful application in information security.

Red/NIR emission carbonized polymer dots based on citric acid-benzoylurea and their application in lymph nodes imaging

Identification of lymph nodes (LNs) is critical for studies of the structure, the role in disease development, and the efficacy of disease treatment. Carbonized polymer dots (CPDs) are expected to be potential LNs-targeted imaging agents due to their excellent properties with special structure, better photoluminescence (PL) and great biocompatibility. Herein, a red/near infrared (NIR) emission CPDs (RCPDs) with one and two-photon bioimaging based on citric acid (CA) and benzoylurea (BU) are prepared. Notably, the RCPDs are capable of targeting LNs for imaging. Lymphocyte homing has been demonstrated to be the cellular mechanism of RCPDs target LNs imaging. This work has developed a new nanomaterial for targeted imaging of LNs, while the biological applications of CPDs have been expanded and deepened.

Lights and Dots toward Therapy-Carbon-Based Quantum Dots as New Agents for Photodynamic Therapy.

The large number of deaths induced by carcinoma and infections indicates that the need for new, better, targeted therapy is higher than ever. Apart from classical treatments and medication, photodynamic therapy (PDT) is one of the possible approaches to cure these clinical conditions. This strategy offers several advantages, such as lower toxicity, selective treatment, faster recovery time, avoidance of systemic toxic effects, and others. Unfortunately, there is a small number of agents that are approved for usage in clinical PDT. Novel, efficient, biocompatible PDT agents are, thus, highly desired. One of the most promising candidates is represented by the broad family of carbon-based quantum dots, such as graphene quantum dots (GQDs), carbon quantum dots (CQDs), carbon nanodots (CNDs), and carbonized polymer dots (CPDs). In this review paper, these new smart nanomaterials are discussed as potential PDT agents, detailing their toxicity in the dark, and when they are exposed to light, as well as their effects on carcinoma and bacterial cells. The photoinduced effects of carbon-based quantum dots on bacteria and viruses are particularly interesting, since dots usually generate several highly toxic reactive oxygen species under blue light. These species are acting as bombs on pathogen cells, causing various devastating and toxic effects on those targets.

Reinforced copper matrix composites with highly dispersed nano size TiC in-situ generated from the Carbon Polymer Dots

In order to uniformly disperse the ceramic reinforcements synthesized in situ in the copper matrix composites, this study used Carbon Polymer Dot (CPD) as the carbon source and Cu-1.0%Ti alloy powder as the matrix to supply the Ti source for manufacturing in situ synthesized TiC/Cu composites. The results showed that TiC nano-precipitate formed in the grains interior and grain boundaries, with particle sizes that were similar to the CPD size and maintained a uniform distribution state. Compared with the matrix, 0.3 wt% CPD/Cu composite displayed the best strength-plastic compatibility, the UTS had achieved to be 385 MPa accompanied with a corresponding EL of 21%. This was owing to the dislocation hindrance caused by nano-carbide and excellent interface bonding between nano TiC and the Cu matrix. The density function theory calculation had supported our experimental results, which showed a tighter and stronger interface contact. This paper presents a new approach for studying in situ carbide precipitates. To create the in situ synthesized nano-sized TiC/Cu composites, Carbon Polymer Dot (CPD) was used as the carbon source. Theoretical and experimental findings support the strong interfacial bonding between TiC and copper matrix. The proposed method of in-situ synthesized nano-scaled TiC demonstrates to be a novel way to construct high-performance Cu matrix composites with both enhanced strength and plasticity.

Red emissive nanocomposite with high quantum yield for ultrasensitive and selective detection of latent fingerprints

Level 1–3 minutiae of latent fingerprints (LFPs) play essential roles in the identification of individuals. The level 3 details of sweat pores are especially important for accurate LFPs recognition, as they can provide microscopic features. Fluorescent materials with high quantum yield and red emission are advantageous in the LFPs detection, due to the associated potential of elevated sensitivity and contrast. Herein, a highly fluorescent red emissive nanocomposite material (PPDCDs@ZIF-8) was successfully prepared by combining carbonized polymer dots of PPDCDs with zeolitic imidazolate framework ZIF-8 in situ. The obtained material displays a strong and stable red emission at solid state with the maximum peak located at 630 nm, and the fluorescence quantum yield of PPDCDs is significantly improved from 17.8% to 43.5% after conjugation with ZIF-8. This nanocomposite material was successfully applied to detect LFPs on glass, metal, marble and other substrates with ultrahigh sensitivity. The obtained fluorescent images clearly revealed the detailed LFPs features from level 1 to level 3. Therefore, PPDCDs@ZIF-8 possesses great potential applications in crime scenes as it provides an easy and accurate strategy to visual the sweat pores in LFPs.

Inhibition mechanism of human insulin fibrillation by Bodipy carbon polymer dots and photothermal defibrillation effect of Bodipy carbon polymer dots modified by ThT

Fibrillation process of human insulin (HI) is closely related to type 2 diabetes (T2D). In the present work, Carbon Polymer Dots (CPDs) was synthesized by Bodipy to control the process of insulin fibrillation. The inhibition process of insulin fibrillation with the existence of CPDs was completed investigated. The hydrophobic interaction of CPDs and insulin was used to inhibit the change of insulin's secondary structure in the lag phase and growth period. ThT fluorescence analysis and transmission electron microscopy (TEM) characterization of the CPDs were used to explore the kinetics of insulin fibrillation and regulation process by CPDs. Isothermal titration calorimetry (ITC) was applied to explore the regulatory mechanism by CPDs at all stages of the insulin fibrillation process. ThT was used to complete the chemical modification of CPDs by Friedel-Crafts alkylation, which made the CPDs maintain the characteristics of photothermal effect and also obtain the ability to bind specifically to the fibers. Finally, the process of defibrillation of human insulin fibers under the Near-infrared light's irradiation was realized. In this work, we clarified the mechanism of the regulation process by Bodipy CPDs and made CPDs able to defibrillate the insulin fibers by chemical modification.

Water-soluble carbonized polymer dots with tunable solid- and dispersion-state fluorescence for multicolor films, anti-counterfeiting, and fungal imaging

Water-soluble carbonized polymer dots (CPDs) with both superior solid/aggregation-state fluorescence (SSF) and dispersion-state fluorescence (DSF) are highly desired for biological, optoelectronic, and information safety applications due to their quenching-resistance and low toxicity. In this study, three matrix-free silicon-, europium/silicon-, and terbium/silicon-doped CPDs (Si-CPDs, Eu/Si-CPDs, and Tb/Si-CPDs) possessing favorable powder white SSF and aqueous concentration-dependent DSF were achieved by introducing the unique structures of sp2/sp3-hybridized carbon cores with abundant surface N, O, Si-related functional groups and polymer chains through one-step hydrothermal synthesis. The participations of Eu3+ and Tb3+ salts in the synthesis bestowed the corresponding Eu/Si-CPDs and Tb/Si-CPDs with higher graphitic N, accompanied by the red-shifted SSF and DSF emissions. Nevertheless, compared with Si-CPDs, Eu/Si-CPDs with ultratrace Eu (<0.001%) showed stronger powder photoluminescence quantum yield but weaker solution ones, while Tb/Si-CPDs with 0.96% Tb had both weaker powder and solution ones, suggesting the occurrence of electron transfer from CPDs to Eu3+ in dispersion state. The three CPDs solutions exhibited red-shifted luminescence from the cooperative carbon core and sub-fluorophores to the surfaces with their concentrations ranging from 1 to 200 mg/mL, causing the turning on of pale-yellow ice SSF. Interestingly, Si-CPDs, Eu/Si-CPDs, and Tb/Si-CPDs films, formed from their solutions, presented unprecedented multicolor SSF from blue to red, initiated by CPDs skeletons and trace Eu3+/Tb3+, through modulating the excitation wavelength. Importantly, these advanced merits successfully expanded the applications of as-prepared CPDs in anti-counterfeiting and pathogenic fungi detection, affording a new perspective for designing versatile quenching-resistant optical materials.