Red Room Temperature Phosphorescence in Non-Aromatic Carbonized Polymer Dots.

Achieving red organic room temperature phosphorescence (RTP) remains a significant challenge, especially in a non-aromatic system. Herein, red RTP with emission at 605 and 645 nm is achieved through inducing and confining carboxyl dimer association (CDA), a unique hydrogen-bonded coupling red phosphorescence unit, in non-aromatic carbonized polymer dots (CPDs). The CPDs are synthesized via microwave method by using polyacrylic acid (PAA), succinic acid (SA), and traces of phosphoric acid as precursors.

Crosslink-Enhanced Emission-Dominated Design Strategy for Constructing Self-Protective Carbonized Polymer Dots With Near-Infrared Room-Temperature Phosphorescence.

Self-protective carbonized polymer dots (CPDs) with advantageous crosslinked nano-structures have attracted considerable attention in metal-free room temperature phosphorescence (RTP) materials, whereas their RTP emissions are still limited to short wavelength. Expanding their RTP emissions to Near-Infrared (NIR) range is attractive but suffers from the difficulties in constructing narrow energy levels and inhibiting intense non-radiative decay. Herein, a crosslink-enhanced emission (CEE)-dominated construction strategy was proposed, achieving desired NIR RTP (710 nm) in self-protective CPDs for the first time.

Enabling Carbonized Polymer Dots with Color-tunable Time-dependent Room Temperature Phosphorescence through Confining Carboxyl Dimer Association.

Developing a facile strategy to realize fine-tuning of phosphorescence color in time-dependent room temperature phosphorescence (RTP) materials is essential but both theoretically and practically rarely exploited. Through simultaneously confining carboxyl dimer association and isolated carboxyl into the particle via a simple hydrothermal treatment of polyacrylic acid, a dual-peak emission of red phosphorescence (645 nm) and green phosphorescence (550 nm) was observed from carbonized polymer dots (CPDs). The ratio of the two luminescent species can be well regulated by hydrochloric acid inhibiting the dissociation of carboxyl to promote hydrogen bond.

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).

Carbon Dots Based Photoinduced Reactions: Advances and Perspective.

Seeking clean energy as an alternative to traditional fossil fuels is the inevitable choice to realize the sustainable development of the society. Photocatalytic technique is considered a promising energy conversion approach to store the abundant solar energy into other wieldy energy carriers like chemical energy. Carbon dots, as a class of fascinating carbon nanomaterials, have already become the hotspots in numerous photoelectric researching fields and particularly drawn keen interests as metal-free photocatalysts owing to strong UV-vis optical absorption, tunable energy-level configuration, superior charge transfer ability, excellent physicochemical stability, facile fabrication, low toxicity, and high solubility.

Near-Infrared Carbonized Polymer Dots for NIR-II Bioimaging.

Carbon dots (CDs) or carbonized polymer dots (CPDs) are an emerging class of optical materials that have exceptional applications in optoelectronic devices, catalysis, detection, and bioimaging. Although cell studies of CPDs have produced impressive results, in vivo imaging requires available CPDs to fluoresce in the near-infrared-II (NIR-II) window (1000-1700 nm). Here, a two-step bottom-up strategy is developed to synthesize NIR-CPDs that provide bright emissions in both NIR-I and NIR-II transparent imaging windows.

Soft-Hard Segment Combined Carbonized Polymer Dots for Flexible Optical Film with Superhigh Surface Hardness.

The rapid development of optical and electronic devices has driven up the demand of high performance optical protective films to avoid exterior influence and extend the service life. But it is not easy to obtain an ideal coating film with high transmittance, high hardness, and good flexibility. Herein, by taking advantage of the special core-shell structure of carbonized polymer dots (CPDs), we propose a strategy to build up a nanoscale soft-hard segment microstructure for optical protective coating materials.

Confined-domain crosslink-enhanced emission effect in carbonized polymer dots.

Revealing the photoluminescence (PL) origin and mechanism is a most vital but challenging topic of carbon dots. Herein, confined-domain crosslink-enhanced emission (CEE) effect was first studied by a well-designed model system of carbonized polymer dots (CPDs), serving as an important supplement to CEE in the aspect of spatial interactions. The "addition-condensation polymerization" strategy was adopted to construct CPDs with substituents exerting different degrees of steric hindrance.

Precursor-dependent structural diversity in luminescent carbonized polymer dots (CPDs): the nomenclature.

Carbon dots (CDs) have received immense attention in the last decade because they are easy-to-prepare, nontoxic, and tailorable carbon-based fluorescent nanomaterials. CDs can be categorized into three subgroups based on their morphology and chemical structure: graphene quantum dots (GQDs), carbon quantum dots (CQDs), and carbonized polymer dots (CPDs). The detailed structures of the materials can vary significantly, even within the same category.

Carbonized Polymer Dots with Tunable Room-Temperature Phosphorescence Lifetime and Wavelength.

Recently, the room-temperature phosphorescence (RTP) properties of carbon dots (CDs) have attracted significant interest. However, the regulation of RTP emission faces great challenges because of untunable emissive lifetime and wavelength. Here, ultrahigh-yield acrylamide-based N-doped carbonized polymer dots (AN-CPDs) with ultralong RTP lifetime are synthesized by a one-step hydrothermal addition polymerization and carbonization strategy.

Recent Advances in Energy Conversion Applications of Carbon Dots: From Optoelectronic Devices to Electrocatalysis.

Exploitation and utilization of sustainable energy sources has increasingly become the common theme of global social development, which has promoted tremendous development of energy conversion devices/technologies. Owing to excellent and unique optical/electrical properties, carbon dots (CDs) have attracted extensive research interest for numerous energy conversion applications. Strong absorption, downconversion photoluminescence, electron acceptor/donor characteristics, and excellent electron conductivity endow CDs with enormous potential for applications in optoelectronic devices.

Crosslink-Enhanced Emission Effect on Luminescence in Polymers: Advances and Perspectives.

The crosslink-enhanced emission effect was first proposed to explore the strong luminescence of nonconjugated polymer dots possessing only either non-emissive or weakly emissive sub-luminophores. Interesting phenomena in recent research indicate such enhancement caused by extensive crosslinking appears in diverse luminescent polymers with sub-luminophores (electron-rich heteroatomic moieties) or luminophores (conjugated π domains). This enhancement can promote the emission from nonluminous to luminous, from weakly luminous to strongly luminous, and even convert the pathway of radiative transitions.

Carbonized Polymer Dots: A Brand New Perspective to Recognize Luminescent Carbon-Based Nanomaterials.

Carbon dots (CDs), as emerging luminescent nanomaterials, possess excellent but complex properties, bringing about extensive attention and a lot of controversy. In this Perspective, we put forward the concept of "carbonized polymer dots" and emphasize the important role of polymerization and carbonization during the formation of CDs. We explore the common characters and clarify the complicated relationship of CDs, based on the reasonable classification of graphene quantum dots, carbon quantum dots, and carbonized polymer dots.

Insights into supramolecular-interaction-regulated piezochromic carbonized polymer dots.

The photoluminescence (PL) mechanism plays a significant role in the study of carbonized polymer dots (CPDs). The supramolecular interaction exists in most materials, which offers innate methods to regulate the optical and physical properties. However, insights into the tunable red- and blue-shifted PL peaks of CPDs by the supramolecular interaction still remain elusive.

Hydrothermal Addition Polymerization for Ultrahigh-Yield Carbonized Polymer Dots with Room Temperature Phosphorescence via Nanocomposite.

Hydrothermal/solvothermal treatments have been widely used to prepare carbonized polymer dots (CPDs) through the condensation and carbonization of small molecules and/or polymers. However, the basic scientific issues, such as the nucleation and growth process, morphology and size control, yield increase, and photoluminescence (PL) mechanism have not been well investigated. In this work, enlightened by the principle of soap-free emulsion polymerization, CPDs with ultrahigh yields (ca.

Design of Metal-Free Polymer Carbon Dots: A New Class of Room-Temperature Phosphorescent Materials.

Polymer carbon dots (PCDs) are proposed as a new class of room-temperature phosphorescence (RTP) materials. The abundant energy levels in PCDs increase the probability of intersystem crossing (ISC) and their covalently crosslinked framework structures greatly suppress the nonradiative transitions. The efficient methods allow the manufacture of PCDs with unique RTP properties in air without additional metal complexation or complicated matrix composition.

Berberine-based carbon dots for selective and safe cancer theranostics.

Fluorescent berberine-based carbon dots (Ber-CDs) were prepared through a facile synthesis strategy. Ber-CDs exhibited excellent optical properties for bioimaging and retained the biofunctions of berberine, and enabled selective and safe anti-tumor performance, demonstrating their promising application potential in cancer theranostics.

Full-Color Emission Polymer Carbon Dots with Quench-Resistant Solid-State Fluorescence.

Polymer carbon dots (PCDs) represent a new class of carbon dots (CDs) possessing sub-fluorophores and unique polymer-like structures. However, like small molecule dyes and traditional CDs, PCDs often suffer from self-quenching effect in solid state, limiting their potential applications. Moreover, it is hard to prepare PCDs that have the same chemical structure, exhibiting full-color emission under one fixed excitation wavelength by only modulating the concentration of the PCDs.

Supramolecular Cross-Link-Regulated Emission and Related Applications in Polymer Carbon Dots.

Involvement of clear photoluminescence (PL) mechanism in specific chemical structure is at the forefront of carbon dots (CDs). Supramolecular interaction exists in plenty of materials, offering an inherent way to administrate the optical and photophysical properties, especially in terms of newly developed polymer carbon dots (PCDs). However, supramolecular-interaction-derived PL regulation is always ignored in the shadow of many kinds of PL factors, and we still have a limited understanding on the distinct chemical structure and mechanism of supramolecular effect in PCDs.