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41.
42.
Hierarchical comb brush architectures via sequential light‐mediated controlled radical polymerizations 下载免费PDF全文
Benjaporn Narupai Justin E. Poelma Christian W. Pester Alaina J. McGrath Edward P. Toumayan Yingdong Luo John W. Kramer Paul G. Clark Paresh C. Ray Craig J. Hawker 《Journal of polymer science. Part A, Polymer chemistry》2016,54(15):2276-2284
A novel strategy for the synthesis and characterization of branched polymer brushes by sequential light‐mediated controlled radical polymerizations is described. Initially, linear brushes are prepared by surface‐initiated copolymerization of methyl methacrylate and 2‐hydroxyethyl methacrylate (HEMA). In a subsequent step, the HEMA side chains are functionalized with initiating groups for secondary graft polymerization, leading to hierarchical, branched architectures. The increased steric bulk due to the polymer side chains results in a dramatic increase in film thickness when compared to the starting linear brushes. This strategy also allows chemical gradient and complex three‐dimensional structures to be obtained by employing grayscale photomasks in combination with controlled radical polymerization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2276–2284 相似文献
43.
Santokh S. Tandon Scott D. Bunge Neil Patel Esther C. Wang Laurence K. Thompson 《Molecules (Basel, Switzerland)》2020,25(23)
The self-assembly of 2,6-diformyl-4-methylphenol (DFMP) and 1-amino-2-propanol (AP)/2-amino-1,3-propanediol (APD) in the presence of copper(II) ions results in the formation of six new supramolecular architectures containing two versatile double Schiff base ligands (H3L and H5L1) with one-, two-, or three-dimensional structures involving diverse nuclearities: tetranuclear [Cu4(HL2−)2(N3)4]·4CH3OH·56H2O (1) and [Cu4(L3−)2(OH)2(H2O)2] (2), dinuclear [Cu2(H3L12−)(N3)(H2O)(NO3)] (3), polynuclear {[Cu2(H3L12−)(H2O)(BF4)(N3)]·H2O}n (4), heptanuclear [Cu7(H3L12−)2(O)2(C6H5CO2)6]·6CH3OH·44H2O (5), and decanuclear [Cu10(H3L12−)4(O)2(OH)2(C6H5CO2)4] (C6H5CO2)2·20H2O (6). X-ray studies have revealed that the basic building block in 1, 3, and 4 is comprised of two copper centers bridged through one μ-phenolate oxygen atom from HL2− or H3L12−, and one μ-1,1-azido (N3−) ion and in 2, 5, and 6 by μ-phenoxide oxygen of L3− or H3L12− and μ-O2− or μ3-O2− ions. H-bonding involving coordinated/uncoordinated hydroxy groups of the ligands generates fascinating supramolecular architectures with 1D-single chains (1 and 6), 2D-sheets (3), and 3D-structures (4). In 5, benzoate ions display four different coordination modes, which, in our opinion, is unprecedented and constitutes a new discovery. In 1, 3, and 5, Cu(II) ions in [Cu2] units are antiferromagnetically coupled, with J ranging from −177 to −278 cm−1. 相似文献
44.
Ze-Lin Zheng Ming-Min Wu Xian Zeng Dr. Xiao-Wei Zhu Dong Luo Xue-Ling Chen Yan-Fei Chen Guo-Zhan Yang Prof. De-Shan Bin Prof. Xiao-Ping Zhou Prof. Dan Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(15):e202400012
Hollow nanoporous carbon architectures (HNCs) present significant utilitarian value for a wide variety of applications. Facile and efficient preparation of HNCs has long been pursued but still remains challenging. Herein, we for the first time demonstrate that single-component metal–organic frameworks (MOFs) crystals, rather than the widely reported hybrid ones which necessitate tedious operations for preparation, could enable the facile and versatile syntheses of functional HNCs. By controlling the growth kinetics, the MOFs crystals (STU-1) are readily engineered into different shapes with designated styles of crystalline inhomogeneity. A subsequent one-step pyrolysis of these MOFs with intraparticle difference can induce a simultaneous self-hollowing and carbonization process, thereby producing various functional HNCs including yolk-shell polyhedrons, hollow microspheres, mesoporous architectures, and superstructures. Superior to the existing methods, this synthetic strategy relies only on the complex nature of single-component MOFs crystals without involving tedious operations like coating, etching, or ligand exchange, making it convenient, efficient, and easy to scale up. An ultra-stable Na-ion battery anode is demonstrated by the HNCs with extraordinary cyclability (93 % capacity retention over 8000 cycles), highlighting a high level of functionality of the HNCs. 相似文献
45.
《Macromolecular rapid communications》2017,38(4)
This feature article briefly highlights some of the recent advances in polymers in which phosphorus is an integral part of the backbone, with a focus on the preparation of functional, highly branched, soluble polymers. A comparison is made between the related families of materials polyphosphazenes, phosphazene/phosphorus‐based dendrimers and polyphosphoesters. The work described herein shows this to be a rich and burgeoning field, rapidly catching up with organic chemistry in terms of the macromolecular synthetic control and variety of available macromolecular architectures, whilst offering unique property combinations not available with carbon backbones, such as tunable degradation rates, high multivalency and facile post‐polymerization functionalization. As an example of their use in advanced applications, we highlight some investigations into their use as water‐soluble drug carriers, whereby in particular the degradability in combination with multivalent nature has made them useful materials, as underlined by some of the recent studies in this area.
46.
《Journal of separation science》2017,40(8):1765-1772
A three‐dimensional reduced graphene oxide aerogel with embedded nickel oxide nanoparticles was prepared by a one‐step self‐assembly reaction in a short time. The nanoparticles could be captured into the interior of reduced graphene oxide network during the formation of the three‐dimensional architecture. The composite exhibited porosity, good biocompatibility, and abundant metal affinity binding sites. The aerogel was used to isolate ovalbumin selectively from egg white, and favorable adsorption was achieved at pH 3. An adsorption efficiency of 90.6% was obtained by using 1 mg of the composite for adsorbing 70 μg/mL of ovalbumin in 1.0 mL of sample solution, and afterwards a recovery of 90.7% was achieved by using an eluent of 1.0 mL Britton–Robinson buffer solution at pH 5. After the adsorption/desorption, ovalbumin showed no change in the conformation. The adsorption behavior of ovalbumin on the reduced graphene oxide composite well fitted to the Langmuir adsorption model, and a corresponding theoretical maximum adsorption capacity was 1695.2 mg/g. A sodium dodecyl sulfate polyacrylamide gel electrophoresis assay demonstrated that the aerogel could selectively isolate ovalbumin from chicken egg white. 相似文献
47.
The new complexes [Ni(Hbstbh)2(en)] (1) and [Ni(Hpchce)(o-phen)2]Cl·CH3OH·H2O (2) with N′-benzoyl hydrazine carbodithioic acid benzyl ester (H2bstbh) and [N′-(pyridine-4-carbonyl)-hydrazine]-carbodithioic acid ethyl ester (H2pchce) have been synthesized, containing ethylenediamine (en) or o-phenanthroline (o-phen) as coligands. The ligands and their complexes have been characterized by elemental analyses, IR, magnetic susceptibility and single crystal X-ray data. [Ni(Hbstbh)2(en)] (1) and [Ni(Hpchce)(o-phen)2]Cl·CH3OH·H2O (2) crystallized in the monoclinic and triclinic systems, space group C2/c and P-1, respectively. The (N, O) donor sites of the bidentate ligands chelate the Ni(II) center and form a five-membered CN2ONi ring. The resulting complexes are paramagnetic and have a distorted octahedral geometry. 相似文献
48.
Vlad Hurduc Maria Bercea Maria Lungu Iulian Nor 《Journal of Macromolecular Science: Physics》2013,52(2):379-390
Polysiloxane-g-(styrene-co-butyl acrylate) copolymers with different architectures (four-armed star and brush) were synthesized and introduced into an alkydic resin in order to improve the flow properties and formulate new systems for painting applications. The viscoelastic properties of the alkydic resin as compared with the additives samples were investigated at different temperatures in the range of 0°C to 80°C. The experimental data showed that a small quantity of polymers with controlled architectures determines changes in the rheological behaviour of the resin solutions, the brush copolymer being more efficient as a viscosity improver. 相似文献
49.
Optical burst switching (OBS) is a promising paradigm for the next-generation Internet infrastructure. In this paper, a novel efficient network architecture for OBS has been presented and compared with conventional OBS architectures. To enhance OBS system performance, the architecture employs a novel proposed burst assembly algorithm, fiber delay lines (FDLs) and dynamic route selection technique. A queuing model is used to predict the system behavior for both classless and prioritized traffic. Simple closed-form expressions are obtained for the burst-loss probability of both classless and prioritized traffic. Numerical results show that the proposed architecture provides an accurate fit for the performance of the highest traffic class and lower bounds for the other traffic classes that are tighter than earlier known results. 相似文献
50.
Mengjun Wang Xusheng Du Huasheng Tian Qiong Jia Rong Deng Yahan Cui Chunyu Wang Kamel Meguellati 《中国化学快报》2019,30(2):345-348
Two strategies for the design of new pillar[5]arene-based mechanically self-interlocked molecules (MSMs) are reported here. The first strategy is based on the construction of an intermediate pseudo[1]rotaxane followed by the desired bis-[1]rotaxane. The other one is based on the construction of the desired bis-[1]-rotaxane directly via a condensation reaction through host-guest interactions between a mono-functionalized pillar[5]arene and the axle. This compound has interesting self-assembly properties in methanol and some extended applications of this compound will be reported in the near future. 相似文献