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 for supplying Ti source to prepare in-situ synthesized TiC/Cu composites.The results show that TiC nano-precipitates,having the similar particle sizes with the CPD,form at the grains interior and grain boundaries,and maintain a uniform distribution state.Compared with the matrix,0.3 wt%CPD/Cu composite displays the best strengthplastic compatibility,the ultimate tensile strength achieves 385 MPa accompanied with a corresponding elongation of 21%,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 supports our experimental results by showing a tighter and stronger interface contact.This work presents a new approach for studying in-situ carbide precipitates.

The Current Progress and Challenges of Carbonized Polymer Dot-Based Room-Temperature Phosphorescent Materials

Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between their special structures and luminescent properties.In recent years,great progress has been made in the field of CPD-based room-temperature phosphorescent materials.This review pays particular attention to how the special“core–shell”structure of CPDs influences the activation of roomtemperature phosphorescence(RTP).The strategies and vital factors to activate RTP for CPD-based materials in both solid state and water were reviewed in detail to elaborate on the effect of the special structure on RTP generation.Furthermore,some perspectives on the current challenges were also provided to guide the further development of CPD-based room-temperature phosphorescent materials.

Polyelectrolyte complex-based thermochromic hydrogels containing carbonized polymer dots for smart windows with fast response,excellent solar modulation ability,and high durability

Thermochromic smart windows have gained increasing popularity in light modulation and energy management in buildings.However,the fabrication of flexible thermochromic smart windows with high luminous transmittance(Tlum),tailorable critical temperature(τc),strong solar modulation ability(ΔTsol),and long-term durability remains a huge challenge.In this study,hydrogel-based thermochromic smart windows are fabricated by sandwiching thermochromic hydrogels of polyallylamine hydrochloride,polyacrylic acid,and carbonized polymer dots(CPDs)complexes between two pieces of transparent substrates.Benefiting from the incorporation of nanosized CPDs,the thermochromic hydrogel has an ultrahigh Tlum of~98.7%,a desirableτc of~24.2℃,aΔTsol of~89.3%and a rapid transition time of~3 s from opaque state to transparent state.Moreover,the thermochromic hydrogel exhibits excellent anti-freezing ability,tight adhesion toward various substrates,and excellent self-healing capability.The self-healing capability enables the fabrication of large-area smart windows by welding multiple hydrogel pieces.The smart windows retain their original thermochromic properties after being stored under ambient conditions for at least 147 days or undergoing 10,000 uninterrupted heating/cooling cycles.The model houses with smart windows can achieve a temperature reduction of 9.2℃,demonstrating the excellent indoor temperature modulation performance of the smart windows.

沸石鞣透明皮革的制备及荧光防伪探索

本文采用“自上而下”的制备策略,结合“浸渍-聚合填充”工艺,以沸石鞣绵羊皮(ZSL)为原料,成功制备出沸石鞣基透明皮革(ZSTL)。着重探究了ZSL的厚度、染料的种类、染料的用量对ZSTL透明性和机械性能的影响,同时考察了ZSTL的细胞毒性和规模化制备工艺的可行性。结果表明:ZSTL具有较高的透明性和拉伸强度,即使由1.2 mm厚度的ZSL制备的ZSTL在550 nm波长下的透过率也超过了67.4%,且ZSTL的最大断裂拉伸强度达到了10.35 MPa,韧性为1054 kJ/m^(3);染料对ZSTL透明性的影响较小,它的引入能提升ZSTL的机械性能,最大断裂拉伸强度达到了12.69 MPa,韧性为1501 kJ/m^(3);ZSTL并未表现出细胞毒性,即使在100%的浸提浓度下,细胞活性依然高于80%。利用该工艺可以成功制备面积为600 cm^(2)的ZSTL,这为ZSTL的规模化生产提供了切实可行的方案。此外,采用荧光CQDs可以在ZSTL上构筑出长期稳定的防伪标签,且具有制备光致变色透明皮革的潜力。

The Behavior of Carbonized Polymer Dots at the Nano-Bio Interface and Their Luminescent Mechanism:A Physical Chemistry Perspective

Carbonized polymer dots(CPDs)have been widely applied in biomedical fields,such as imaging,diagnosis and drug delivery.Since the complex,non-equilibrated and dynamic nature of biological systems inevitably affect the predesigned properties of CPDs,then efficiency and ultimate outcome of CPDs in biological identity will be transformed by the ubiquitous nano-bio interactions.Herein,our recent progress about elucidating the behavior of CPDs at nano-bio interface from the perspective of physical chemistry has been summarized in the review,mainly at the bio-macromolecular,cellular membrane and cellular levels,which is crucial for characterize their relative cytotoxicity and clinical transformation.Moreover,we mainly focused on the quantitative relationship of nano-bio interactions between CPDs with biological identity and related thermodynamics parameters during this process is also obtained from advanced isothermal titration calorimetry technique.Finally,our recent study about the photoluminescence origin is also included in this review,which favors modulating the photoluminescence of CPDs.

Surface-state triggered solvatochromism of carbonized polymer dot and its two-photon luminescence

This study reports a new nitrogen-doped carbonized polymer dot(CPD)-based solvatochromic probe.Its color-changing for different solvents was explored in detail by the measurements of photophysical parameters(involving Stokes shifts,fluorescence quantum yield,fluorescence lifetime,radiative decay rate constant,and non-radiative decay rate constant)and the following analyses according to Lippert–Mataga equation and Kamlet–Taft model.The hydrogen bonding effect of the CPD in protonic solvents was semi-quantitatively assessed.It takes charge of the solvatochromic phenomenon,especially in proton solvents.Interestingly,this CPD exhibits two-photon solvatochromism.Moreover,the relations between the photophysical parameters and the surface states of CPD in aprotic and proton solvents were depicted.The results reveal the nitrogen doping in the CPD impacts the up-and down-conversion solvatochromic features from the comparison between N-free and N-doped CPDs in many characterizations.In addition,this N-doped CPD was dispersed into polymer matrices to fabricate tunable solid-state luminescent films,which is another model for evidencing the interactions of the CPD with surroundings.This study is of significance in understanding the surface-state controlled luminescence in the CPDs,and will be beneficial for developing new smart,responsive carbon-based nanoprobes.

Achieving blue water-dispersed room-temperature phosphorescence of carbonized polymer dots through nano-compositing with mesoporous silica

Stabilizing triplet excited states is important for room temperature phosphorescence(RTP)materials to achieve multifunctional applications in humid environment.However,due to the lack of preparation strategies,the realization of RTP materials in water still faces challenges.Herein,a new design strategy was presented to achieve RTP in water by confining carbonized polymer dots(CPDs)in amino functional mesoporous silica(MSNs-NH_(2)).The as-prepared MSNs-CPDs aqueous dispersion exhibited blue afterglow,lasting more than 3 s to naked eyes.The triplet excited states were protected from non-radiative deactivation by the double-confinement effect including covalent bonding fixation and mesoporous structure confinement.The MSNs-CPDs inherited the structure of MSNs-NH_(2),so the stability of morphology and properties were superior to CPDs and even most of silica-based CPDs RTP materials.A water-related encryption technique demonstrated the promising application of MSNs-CPDs as smart materials in the field of information security.Besides,the possibility of potential application in ion detection was also explored.

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

Comprehensive Summary Currently,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.

Aggregation and luminescence in carbonized polymer dots

The aggregate luminescence behavior of organic luminescent materials has been studied extensively.As a new kind of luminescent nanomaterials,carbonized polymer dots(CPDs)not only inherit the stability and biocompatibility of carbon materials,but also possess the luminescence tunability,water solubility,and high photoluminescence quantum yield of organic luminescent materials,rendering them a strong candidate for the next generation of light-emitting materials.Previously,people mainly understood its luminescence from the perspective of carbon materials,but some luminescence mechanisms are still unclear.In this review,we discuss the luminescence mechanism by referring to organic luminescent materials with emphasis on their aggregation behavior.Firstly,three representative aggregate luminescence phenomena of organic luminescent materials are briefly introduced.Chromophores present in CPDs are elaborated to further discuss the potential interactions between them,with emphasis on the role of crosslinked polymer networks.On this basis,some special luminescence phenomena of CPDs in the aggregate state are summarized,and relevant mechanisms are discussed in detail to consolidate relevant statements.

Dual-emission carbonized polymer dots for ratiometric sensing and imaging of L-lysine and pH in live cell and zebrafish

It is highly desired to accurately and selectively detect and image intracellular L-lysine and pH in biological systems because they could act as the biomarkers in certain abnormal conditions and may give us a warning of the occurrence of diseases.It has been attracted more focuses to design new ratiometric fluorescent probe for monitoring L-lysine and pH to improve detection accuracy.Carbonized polymer dots(CPDs),which possess carbon/polymer hybrid structure rather than pure carbon structure and constitute of a carbon core and large amounts of functional groups/polymer chains on the surface,rise up as a new type of fluorescent nanomaterials and especially display many advantages for bioanalysis.In this study,o-phenylenediamine(o-PD)and poly(styrene-co-maleic anhydride)(PSMA)are used as the precursors to synthesize the desired CPDs through one-step hydrothermal amide method.The prepared CPDs display two well-resolved fluorescence emission bands,i.e.,a very weak emission centered at 470 nm in blue region and a strong emission centered at 558 nm in yellow region.It is found that the two emissions are both responsive to L-lysine based on the surface passivation mechanism,whereas,only the yellow emission is responsive to pH due to the protonation/deprotonation process of the amino groups.Based on the different responsive behaviors,ratiometric detection and imaging of L-lysine and pH are achieved.The prepared ratiometric CPDs probe is successfully applied for L-lysine and pH sensing and imaging at two emission channels in live cell and zebrafish with satisfactory results.

Highly efficient solid-state luminescence of carbonized polymer dots without matrix

Development of high-performance solid state luminescent carbon-based nanomaterials remains challenging.Here,strong blue-green fluorescent carbonized polymer dots(CPDs)from o-aminobenzenethiol and thiosalicylic acid(o ABT-TSA-CPDs)with an absolute photoluminescence quantum yield(PLQY)of 76%in solid state without matrix were synthesized.Through adjusting the reaction temperature and time,the PL centers were proved to be carbon core state and surface state associated to carbonyl group which was the source of strong fluorescence emission in solid state.The mechanism of the unique phenomenon of enhanced emission from ethanol solution(PLQY=7%)to powder(PLQY=76%)was investigated by analyzing the chemical properties and structures of o ABT-TSA-CPDs at different temperatures and o ABT-TSACPDs/PVC composites,and was confirmed as fixation of PL centers.

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.

Polymer types regulation strategy toward the synthesis of carbonized polymer dots with excitation-wavelength dependent or independent fluorescence

Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green and red emissions, respectively. In sharp contrast, two kinds of CPDs prepared via a hydrothermal process from citric acid(CA) and diethylenetriamine(DETA) exhibit obvious excitation-wavelength dependent emissions. Through the characterization and comparison of the two types of CPDs, it is concretely revealed that the polymer structure types during the formation of CPDs can effectively control the fluorescence excitation-wavelength independence/dependence. The homogeneous polymer structures contained in CPDs contribute to excitation-wavelength independence, whereas random copolymer structures contribute to excitation-wavelength dependence. These studies are of great significance for further understanding the polymer structures and designing unique optical properties of CPDs.

CdBiO2Br nanosheets in situ strong coupling to carbonized polymer dots and improved photocatalytic activity for organic pollutants degradation

Carbonized polymer dots(CPDs)modified layer-structured CdBiO_(2)Br(CPDs/CdBiO_(2)Br)Z-scheme heterojunction hybrid material has been synthesized via simple solvothermal method.The hybrid material with Z-scheme heterojunction can effectively maintain the original highly oxidizing holes of CdBiO_(2)Br and the highly reducing electrons of CPDs.In addition,the construction of heterostructure is beneficial to the migration and separation of photogenerated carriers.Under visible light irradiation,6 wt%CPDs/CdBiO_(2)Br showed the best catalytic activity for degradation of organic pollutants.Free radical capture experiments and ESR analysis confirmed that the main active species are·O_(2)^(-)and h^(+).The decomposition process of organic pollutants was analyzed by LC-MS.Finally,the probable visible light mechanism performance of CPDs/CdBiO_(2)Br as direct Z-scheme heterojunction photocatalytic materials was proposed.

共聚阻燃改性聚对苯二甲酸乙二醇酯的制备及其性能

针对聚对苯二甲酸乙二醇酯(PET)阻燃性较差的问题,以[(6-氧代-6H-二苯并[c,e][1,2]氧磷杂己环-6-基)甲基]丁二酸(DDP)和明胶基碳点(gCDs)构建复合阻燃体系,采用原位聚合法制备了阻燃DDP-gCDs-PET,借助扫描电子显微镜、傅里叶变换红外光谱仪对其结构进行分析,通过极限氧指数(LOI)、垂直燃烧(UL-94)及锥形量热指标研究了不同质量分数的gCDs与DDP复配后对PET阻燃性能的影响,并利用热重-傅里叶变换红外光谱分析探究了阻燃PET在气相中的热分解产物,提出了DDP、gCDs对PET的阻燃机制。结果表明:当添加DDP质量分数为8%、gCDs质量分数为1.0%时,DDP-gCDs-PET的UL-94等级提升至V-0级,LOI值可达到35%;相较于纯PET,DDP-gCDs-PET的热释放速率峰值降低39.77%,总热释放量降低25.00%,引燃时间延长25 s,阻燃效果显著改善;在燃烧过程中DDP促进了PET基体分解并在气相中淬灭自由基,gCDs使热量迅速扩散,提升了PET基体的热稳定性能,且gCDs在凝聚相促进成炭使DDP中的P留存于炭层中,二者共同作用提升了PET的阻燃性能。

Stimulating and harnessing circularly polarized luminescence of helically assembled carbonized polymer dots via interfacial dynamics

Stimulating and harnessing circularly polarized luminescence(CPL)is not only a sine qua non for fundamentally unveiling chirogenesis in physical chemistry,but also a pivotal prerequisite for implementation of such phenomenon in research fields including chiral optoelectronics and theranostics.Herein,red-emissive carbonized polymer dots(CPDs)-based helical structures were synthesized in this work via biomolecule-tailored organic–inorganic co-assembly strategy.The surface statesrelated chirality exhibits enhanced circular dichroism(CD)and CPL activities with anisotropic factors as high as gCD,max=5.4×10^(−3) and glum,max=1.5×10^(−2),respectively.The obtained CPL signals can be further manipulated in an excitationdependent manner,indicating that a synergistic-competition phenomenon exists between configurational chirality and intermolecular energy-transfer dynamics,which is further supported by simulations based on density function theory(DFT).Such tunable CPL behavior triggers revolutionary designs and applications of these chiral CPDs into the realm of chirality-related biological issues and next-generation chiral optoelectronics.

多功能PCL@CD纤维的制备与性能研究

以柠檬酸(CA)和乙二胺(EDA)为原料,采用一步微波法制备了强荧光碳点(CD)。首次采用低毒性植酸(PA)催化ε-己内酯(ε-CL)开环聚合成功制备出生物可降解性聚己内酯碳点杂化材料(PCL@CD),并以不同质量比例的PCL@CD和纯PCL通过静电纺丝获得荧光可降解多功能纤维(SF)。通过对SF进行形态和性能表征,结果表明PCL@CD赋予了SF优异的光学性能和良好的亲水性。最后将由还原法制备出的银纳米颗粒浸入SF中获得抗菌纤维(Ag-SF),抗菌测试表明Ag-SF对大肠杆菌和金黄色葡萄球菌具有良好的抗菌性能。

新型功能碳材料的高压截获

高性能功能材料在诸多领域具有广泛的应用前景,是人们一直关注的研究热点。高压可以有效地改变物质的原子间距和成键方式,是获得新型功能材料的重要途径。在碳材料的高压研究中,许多有趣的功能碳材料,如光学透明碳、高强度弹性碳和超硬非晶碳等,已经通过不同的碳前驱体合成。本文简要介绍了作者近年来在低维碳基纳米复合材料高压研究中取得的进展,基于设计的不同低维碳前驱体,高压下截获了具有超硬特性、新型压致共价聚合及发光增强的碳材料。

荧光示踪微球研制及示踪性能

为满足矿场采出液聚合物微球质量浓度检测技术需求,提高对聚合物微球在储层内运移规律的认识,利用荧光分光光度计、高压汞灯紫外光光反应器、全自动酶标仪和荧光显微镜等仪器分析了荧光碳点性能和荧光示踪微球性能。结果表明:荧光碳点具有良好光照耐受性、pH适应性和生物安全性;以种子二次聚合法将荧光碳点与聚合物微球相结合制备荧光示踪微球,可以避免采出液的背底荧光;以采出液的荧光强度峰值计算采出液微球质量浓度并及时调整调驱方案;荧光示踪微球的聚并现象可提高采收率;将荧光碳点与聚合物微球复合注入地层可提高荧光碳点的热稳定性;普通微球和荧光示踪微球均具有较好的注入性能,封堵性能差异不大。研究成果为渤海油田实现大规模聚合物微球的化学调驱提供了有力的技术支持。

高通量荷正电碳量子点杂化纳滤膜的制备及应用

为了提高纳滤膜的分离性能,以表面带有氨基基团碳量子点(Amino-functionalized carbon quantum dots, N-CQD)为填充粒子,采用界面聚合方法制备高通量荷正电杂化聚酰胺纳滤膜,并对N-CQD和杂化纳滤膜结构、形貌和性能进行表征分析。结果表明:良好的亲水性和表面带有可参与界面聚合反应的氨基基团,使N-CQD通过化学键均匀、稳定地分布在聚酰胺基体中,因此可同时提高纳滤膜通量和截留率。在最佳制膜条件下,所制备的纳滤膜的水通量为58.22 L/(m^(2)·h),与未添加N-CQD纳滤膜相比,通量提高了约2.6倍;同时截留的无机盐按截留率从大到小依次为MgCl_(2)(95.4%)、CaCl_(2)(92.1%)、MgSO_(4)(85.2%)、NaCl(64.8%)、Na_(2)SO_(4)(48.6%)。制备得到的纳滤膜对二价阳离子有较高的截留率,在硬水软化领域具有实际应用价值。