Luminescent Thermochromism of 2D Coordination Polymers Based on Copper(I) Halides with 4‐Hydroxythiophenol

Solvothermal reactions between copper(I) halides and 4‐mercaptophenol give rise to the formation of three coordination polymers with general formula [Cu₃X(HT)₂]_n (X=Cl, 1 ; Br, 2 ; and I, 3 ). The structures of these coordination polymers have been determined by X‐ray diffraction at both room‐ and low temperature (110 K), showing a general shortening in Cu?S, Cu?X and Cu?Cu bond lengths at low temperatures. 1 and 2 are isostructural, consisting of layers in which the halogen ligands act as μ₃‐bridges joining two Cu1 and one Cu2 atoms whereas in 3 the iodine ligands is as μ₄‐mode but the layers are quasi‐isostructural with 1 or 2 . These compounds show a reversible thermochromic luminescence, with strong orange emission for 1 and 2 , but weaker for 3 at room temperature, whereas upon cooling at 77 K 1 and 2 show stronger yellow emission, and 3 displays stronger green emission. DFT calculations have been used to rationalize these observations. These results suggest a high potential for this novel and promising stimuli‐responsive materials.     

Optical Devices Constructed from Multiresponsive Microgels

Novel multiresponsive microgels based on poly(N‐isopropylacrylamide) were synthesized to contain triphenylmethane leucohydroxide, and used to construct etalons. The optical properties of the resultant etalons were investigated, and their response to ultraviolet and visible irradiation, solution pH changes, and the presence of a mimic of the nerve agent Tabun characterized. We clearly show that the optical properties of the device depended dramatically on these stimuli. This investigation illustrates the versatility of the microgel‐based etalon structure, and showcases the clear utility of such devices for remote actuation, color tunable optics, sensing, and potential remotely triggered drug delivery applications.     

Functional Polymeric Materials Based on Main‐Group Elements

The past decade has witnessed tremendous advances in the synthesis of polymers that contain elements from the main groups beyond those found in typical organic polymers. Unique properties that arise from dramatic differences in bonding and molecular geometry, electronic structure, and chemical reactivity, are exploited in diverse application fields. Herein we highlight recent advances in inorganic backbone polymers, discuss how Lewis acid/base functionalization of polymers results in unprecedented reactivity, and survey conjugated hybrids with unique electronic structures for sensor and device applications.     

多金属氧酸盐簇-聚合物杂化功能材料的研究进展

随着高新科技的快速发展与日益更替,兼有无机材料多功能性和聚合物可加工性的杂化材料具有重要的应用前景。本文论述并回顾了将多金属氧酸盐簇(Polyoxometalates)与聚合物通过共价键连接制备多金属氧酸盐簇-聚合物杂化物(Polyoxometalate-Polymer Hybrids)的研究现状。依据所制备杂化物中聚合物链的构型进行分类,综述了近年来该领域的研究进展,并重点介绍了本课题组在过去几年里的研究成果。     

Synthesis of multifunctional copolymers of poly(methylphenylsilane) with (R)-N-(1-phenylethyl)methacrylamide,disperse red 1 methacrylate and their optical and photoluminescence properties

Abstract

We report the synthesis and characterization of multifunctional polysilane copolymers containing chiral and azobenzene chromophore as a pendant group. Multifunctional polymers of poly(methylphenylsilane) (PMPS) with (R)-N-(1-phenylethyl)methacrylamide (R-NPEMAM) and disperse red 1 methacrylate (DR1MA) were synthesized in a quartz tube using UV-technique. The molecular weights of such synthesized copolymers were found to be in the order of 10³. The appearance of two glass transition temperatures in DSC indicated that the synthesized copolymers are block copolymers. The electronic absorbance of synthesized polymers was observed at 272?nm (π-π* transition of aromatic ring), 330?nm (σ-σ* transition of Si-Si chain of PMPS) and 475?nm (n-π* with π-π* transition due to azobenzene chromophore of DR1MA unit). The chirality of the synthesized polymer was confirmed through circular dichroism observed at 261?nm. Induced chirality appeared at 330?nm and 470?nm due to the association of the Si-Si chain of PMPS and the presence of azobenzene chromophore of the DR1MA unit respectively. The photoluminescence (PL) properties of the synthesized copolymers (SCDRDM-1B, SCDRDM-2B, and SCDRDM-3B) were observed at 307?nm and 415?nm when excited at 275?nm. The λem was also observed at 415?nm when excited by 325?nm. The multi-emission spectra appeared at 500?nm, 550 and 590?nm are presumed to be due to exciton coupling between azobenzene chromophore of DR1MA, and Si-Si σ-conjugation in association with the aromatic ring of PMPS and chiral unit R-NPEMAM block.     

Se-directed synthesis of polymeric carbon nitride with potential applications in heavy metal-containing industrial sewage treatment

By calcining melamine at 500 °C with selenium powder as the structure director, polymeric carbon nitride could be prepared with enhanced specific surface area and mesoporous volume. Compared with the material fabricated without Se, this cost-effective Se-incorporated PCN (PCN-Se) could adsorb heavy metals (such as Ni, Cu and Pb) much more efficiently. Materials characterizations such as SEM, TEM and XPS demonstrated that the enlarged specific surface area and total mesoporous volume as well as the interaction of the incorporated Se with the metals via coordination should be the promoting factors for the advanced performances of the novel materials.     

A Sustainable Freeze‐Drying Route to Porous Polysaccharides with Tailored Hierarchical Meso‐ and Macroporosity

Bio‐derived polysaccharide aerogels are of interest for a broad range of applications. To date, these aerogels have been obtained through the time‐ and solvent‐intensive procedure of hydrogel fomation, solvent exchange, and scCO2 drying, which offers little control over meso/macropore distribution. A simpler and more versatile route is developed, using freeze drying to produce highly mesoporous polysaccharide aerogels with various degrees of macroporosity. The hierarchical pore distribution is controlled by addition of different quantities of t‐butanol (TBA) to hydrogels before drying. Through a systematic study an interesting relationship between the mesoporosity and t‐butanol/water phase diagram is found, linking mesoporosity maxima with eutectic points for all polysaccharides studied (pectin, starch, and alginic acid). Moreover, direct gelation of polysaccharides in aqueous TBA offers additional time savings and the potential for solvent reuse. This finding is a doorway to more accessible polysaccharide aerogels for research and industrial scale production, due to the widespread accessibility of the freeze drying technology and the simplicity of the method.

     

有机微孔聚合物研究进展

有机微孔聚合物(MOPs)是一类新型的多孔材料,具有合成方法多样、化学和物理性质稳定、孔尺寸可调控、表面可修饰等优点。近年来,MOPs在物理吸附储存气体方面表现出巨大潜力,从而在储氢和温室气体封存方面成为研究的热点之一。本文首先介绍了MOPs的结构类型及特点,分别介绍了自具微孔聚合物、超交联聚合物、共价有机网络以及共轭微孔聚合物的最新进展,分析结构与性能间的关系,并对其在催化、分离和气体储存方面的应用做了简单总结。最后对MOPs未来的研究进行了展望。     

Modulating Hierarchical Micro/Mesoporosity by a Mixed Solvent Approach in Al-MOF: Stabilization of MAPbBr3 Quantum Dots

Various hierarchical micro/mesoporous MOFs based on {[Al(μ-OH)(1,4-NDC)]⋅H₂O} ( MOF1 ) with tunable porosities (pore volume and surface area) have been synthesized by assembling Al^III and 1,4-NDC (1,4-naphthalenedicarboxylate) under microwave irradiation by varying water/ethanol solvent ratio. Water/ethanol mixture has played a crucial role in the mesopore generation in MOF1M₂₅ , MOF1M₅₀ , and MOF1M₇₅ , which is achieved by in situ formation of water/ethanol clusters. By adjusting the ratio of water/ethanol, the particle size, surface area and micro/mesopore volume fraction of the MOFs are controlled. Furthermore, reaction time plays a critical role in mesopore formation as realized by varying reaction time for the MOF with 50 % ethanol ( MOF1M₅₀ ). Additionally, hierarchical MOF ( MOF1M₅₀ ) has been used as a template for the stabilization of MAPbBr₃ (MA=methylammonium) perovskite quantum dots (PQDs). MAPbBr₃ PQDs are grown inside MOF1M₅₀ , where mesopores control the size of PQDs which leads to quantum confinement.     

Electrochemical Growth of Conducting Polymer into Zirconium Oxopolymers Sol-Gel Coatings

Conducting polymer based hybrid materials were synthesized by a new route. The use of pyrrole derivatives functionalized by a carboxylic acid or a -diketone group allows to control the polymerization rate of zirconium tetrapropoxide (Zr(OPr)₄). The organic species entrapped in the resulting hybrid materials yield conducting polymers by electropolymerization. The results show that the formation of the conducting polymers depends on the nature of the monomer. Moreover, the presence of polysiloxane chains within the hybrid materials improves the properties of the latter.     

基于超分子聚合物的自修复材料

材料的自修复功能对于材料应用具有重要的意义,如键组装/解组装常数、键的方向和链的弛豫时间等因素会影响自修复效率。根据提供修复功能的物质构成形式,可以分为外援型自修复材料和本征型自修复材料,其中本征型自修复材料是当前的热点方向,在本征型自修复材料中,超分子自修复材料以其独特的可逆性组装,以及在快速、可逆、多重响应方面的优势而成为研究重点。本文重点阐述了基于不同结合效应的超分子自修复聚合物的研究进展,并对今后的研究方向作了展望,认为材料的耐环境性能能否达标是未来能否获得应用的关键因素之一。     

Kinetic Analysis of Mechanochemical Chain Scission of Linear Poly(phthalaldehyde)

The kinetics of mechanochemical chain scission of poly(phthalaldehyde) (PPA) are investigated. Ultrasound‐induced cavitation is capable of causing chain scission in the PPA backbone that ultimately leads to rapid depolymerization of each resulting polymer fragment when above the polymer's ceiling temperature (T_c). An interesting feature of the mechanochemical breakdown of PPA is that “half‐chain” daughter fragments are not observed, since the depolymerization is rapid following chain scission. These features facilitate the determination of rate constants of activation for multiple molecular weights from a single sonication experiment. Additionally, the degradation kinetics are modified with chain‐end trapping agents through variation of the nature and amount of small molecule nucleophile or electrophile.

     

高分子吸声材料

新型吸声材料要求宽频、强吸收且综合性能良好.高分子材料具有粘弹内阻尼的特性,品种繁多,易于进行分子设计、材料设计和成型加工,是满足该技术要求的首选材料.本文结合近年来高分子吸声材料的应用及研究,从吸声机理和结构设计的角度,讨论了高分子材料的声学特性与研究进展,并展望了高分子吸声材料的前景。     

共轭微孔聚合物及其复合材料的制备及应用

共轭微孔聚合物是一类具有扩展共轭体系的骨架材料,具有比表面积大、稳定性高、微孔大小和体积可精确调控等特点。由于其独特的结构特点,共轭微孔聚合物在各方面展现出巨大的应用潜力,本文综述了共轭微孔聚合物及复合材料的制备方法,以及共轭微孔聚合物在气体吸附和储存、污染物的富集、非均相催化、光发射、化学传感器、光捕集、电能存储等方面的应用。     

二次锂电池聚合物正极材料研究进展

近几十年,二次锂电池作为重要的储能装置得到迅猛发展,而开发高性能的锂电池电极材料一直是电化学能源领域的研究热点之一。与传统无机正极材料相比,聚合物正极材料具有比容量高、柔软性好、廉价易得、环境友好、加工方便、可设计性强等诸多优点。本文综述了导电聚合物、共轭羰基聚合物以及含硫聚合物正极材料的结构特点、电极反应机理、电化学性能和近五年来的重大研究进展,总结了这三类聚合物电极材料的优缺点,并重点介绍了含硫聚合物电极材料中存在的问题及改进手段,最后提出了综合这三类聚合物优点的含硫共轭导电聚合物将会是该领域的研究方向。