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1.
Eight novel PEG-based amphiphilic block copolymers having self-assembling properties has been reported in the present study. The polymers have been synthesized by reacting Poly(ethylene glycols) (PEGs) of different molecular weights viz. 600, 1000, 1500 and 2000 and dimethyl-5-hydroxyisophthalate in presence of concentrated H2SO4 as catalyst in solventless condition at 80–90°C and further alkylating the resulting polymers by attaching octyl and hexadecanyl chains to phenolic hydroxyl group. The resulting functionalized amphiphilic polymers have been characterized by 1H and 13C-NMR spectroscopy. These polymers, when dissolved in water, aggregate to form micelles, giving sizes ranging from 13.00 to 87.24 nm as determined by Dynamic Light Scattering (DLS) instrument. The molecular weights have been also calculated from the DLS and are in the range 3.5×104 to 1.8×106 KDa (Kilo Daltons). Critical Micelle Concentrations (CMC) of the synthesized polymers was determined using electrical conductivity meter with values in the range of 105 to 138 mg L?1 (milligrams per litre).  相似文献   

2.
3D LaIII and 2D CuII coordination polymers with 5-nitroisophthalate anions, [La2(μ-Nip)(μ-SO4)2(H2O)5] n (1) and {[Cu3(μ-OH)2(μ-Nip)2(μ-H2O)2] ·?2H2O} n (2), have been synthesized, characterized and studied by X-ray crystallography. The La atoms have eight–coordinate geometries in distorted square antiprism environments and the Cu atoms have five- and six–coordinate geometries with distorted square pyramidal and octahedral environments. Self-assembly of these compounds in the solid state occurs through coordination and hydrogen bonding.  相似文献   

3.
Twelve amphiphilic polymers were synthesized using poly(ethylene glycols) (PEGs) of different molecular weights, viz. 1000, 2000 and 4000 as hydrophilic block and linkers namely azelaic acid, sebacic acid, dimethyl isophthalate acid and dimethyl terephthalate as hydrophobic block in the presence of catalyst Conc. H2SO4. Synthesized polymers were characterized by using 1H-NMR, 13C-NMR and IR spectroscopy. Micellar sizes of the polymers were determined using Dynamic Light Scattering (DLS) which ranged from 51.6–174 nm for aliphatic polymers and 135.5–371 nm for aromatic polymers. Transmission Electron Microscope (TEM) results confirm the findings of DLS. Critical Micelle Concentrations (CMC) of the synthesized polymers were determined using electrical conductivity meter which ranged from 95 to 130 mg L?1 for aliphatic polymers and 420–1500 mg L?1 for aromatic polymers.  相似文献   

4.
Phenylacetylene derivatives containing carbazole ( 1 ) and fluorene ( 2 ) moieties were polymerized by [Rh(nbd)Cl]2 into corresponding polymers P 1 and P 2 of high molecular weights (Mw ~ 150 × 103–465 × 103) in high yields (up to 98%). The polymers were characterized by NMR, IR, UV, PL, and CV techniques. Hybrids of the polymers with multiwalled carbon nanotubes (MWNTs) were prepared by simply mixing the two components in common organic solvents such as dichloromethane. The solvating power of the polymer carrying the electron‐donating carbazolyl pendant (P 1 ) is stronger than that of its counterpart carrying fluorenyl pendant (P 2 ), due to the stronger donor–acceptor (D–A) interaction between the P 1 chains and the MWNT walls. This work clearly manifests that D–A effect plays an important role in the polymer‐aided MWNT dispersion in organic solvents. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4995–5005, 2009  相似文献   

5.
Twelve amphiphilic polymers were synthesized using poly(ethylene glycols) (PEGs) of different molecular weights, viz. 300, 600 and1000 as hydrophilic block and aliphatic diacids namely glutaric acid, adipic acid, pimelic acid and suberic acid as hydrophobic block in presence of catalyst Conc. H2SO4. Synthesized polyesters were characterized by using 1H-NMR, 13C-NMR and IR spectroscopy. Micellar sizes of the polymers were determined using Dynamic Light Scattering (DLS) which ranged from 127.5–354 nm. Transmission Electron Microscope (TEM) results confirm the findings of DLS. Critical Micelle Concentrations (CMC) of the synthesized polymers were determined using electrical conductivity meter which ranged from 112 to 155 mg L?1.  相似文献   

6.
Binary condensation copolymers of 1,2-ethane dithiol and 1,3-propane dibromide, 1,4-butane dibromide, and 1,6-hexane dibromide were prepared. Yields ranged from 55 to 89% with molecular weights of 1–2 × 104 Daltons. The polymers were synthesized via an SN2 process with and without the presence of water. The polymers were characterized by DSC, viscosity, FT-IR, and 1H-and 13C-NMR spectra.  相似文献   

7.
在溶剂热条件下,合成了2个碱土金属配位聚合物[Ca(tdc)(DMF)2]n1)和[Ba(tdc)]n2)(H2tdc=2,5-噻吩二甲酸),分别用元素分析、红外光谱、X射线单晶衍射、粉末衍射、热重分析和荧光光谱对它们进行了表征。结构分析表明,配合物1具有4,4连接的二维层状结构,拓扑符号为(44·62),而配合物2呈现三维网络结构。固体荧光测试表明配合物1比配合物2具有更显著的荧光性能。  相似文献   

8.
Four coordination polymers, [Ag(L1)](m-Hbdc) (1), [Ag(L1)]2(p-bdc)?·?8H2O (2), [Ag(Hbtc)(L1)][Ag(L1)]?·?2H2O (3) and [Ag2(L2)2](OH-bdc)2?·?4H2O (4), where L1?=?1,1′-(1,4-butanediyl)bis(imidazole), L2?=?1,2-bis(imidazol-1-ylmethyl)benzene, m-H2bdc?=?1,3-benzenedicarboxylic acid, p-H2bdc?=?1,4-benzenedicarboxylic acid, H3btc?=?1,3,5-benzenetricarboxylic acid, and OH–H2bdc?=?5-hydroxisophthalic acid, were synthesized under hydrothermal conditions. Compound 1 contains a–Ag-L1–Ag-L1–chain and a hydrogen-bonding interaction induced–(m-Hbdc)-(m-Hbdc)–chain. Compound 2 consists of two independent–Ag-L1–Ag-L1–chains. P-bdc anions are not coordinated. Hydrogen bonds form a 3D supramolecular structure. A novel (H2O)16 cluster is formed by lattice water molecules in 2. Compound 3 contains a–Ag-L1–Ag-L1–and a–Ag(Hbtc)-L1–Ag(Hbtc)-L1–chain. The packing diagram shows a 2D criss-cross supramolecular structure, with?π?···?π?and C–H ···?π?interactions stabilizing the framework. Compound 4 contains a [Ag2(L2)2]2+ dimer with hydrogen-bonding,?π?··· π, and Ag ··· O interactions forming a 3D supramolecular framework. The luminescent properties for these compounds in the solid state are discussed.  相似文献   

9.
在溶剂热条件下,合成了2个碱土金属配位聚合物[Ca (tdc)(DMF)2]n(1)和[Ba (tdc)]n(2)(H2tdc=2,5-噻吩二甲酸),分别用元素分析、红外光谱、X射线单晶衍射、粉末衍射、热重分析和荧光光谱对它们进行了表征。结构分析表明,配合物1具有4,4连接的二维层状结构,拓扑符号为(44·62),而配合物2呈现三维网络结构。固体荧光测试表明配合物1比配合物2具有更显著的荧光性能。  相似文献   

10.
Sixteen amphiphilic polymers were synthesized using poly(ethylene glycols) (PEGs) of different molecular weights, viz. 1000, 1500, 2000 and 4000 as hydrophilic block and linkers namely azelaic acid, suberic acid, terephthalic acid and glycolic acid as hydrophobic block in the presence of catalyst conc. H2SO4 out of which four with glycolic acid as linker are new. Synthesized polymers were characterized by using 1H-NMR, 13C-NMR and IR spectroscopy. Micellar sizes of the polymers were determined using Dynamic Light Scattering (DLS) technique which ranged from 32.1–262.0 nm and confirmed by Transmission Electron Microscope (TEM) analysis. Molecular weights were determined using HORIBA SZ-100 scientific and varied from 6.5?×?102 to 6.5?×?103 Kilo Daltons(kDa) by Debye plot. Critical Micelle Concentrations (CMC) of the synthesized polymers was determined using electrical conductivity meter and it ranged from 105 to 125 milligrams per litre (mg L?1).  相似文献   

11.
Fluorescent amphiphilic polymers were produced by grafting different types and levels of hydrophobic pendant groups with intrinsic fluorescent properties (fluorenylmethoxy carbonyl (Fmoc), dimethylamino‐1‐naphthalenesulfonyl (Dansyl), and naphthalene (Naphth) to a water soluble homopolymer backbone, polyallylamine (PAA). Non‐fluorescent hydrophobic pendant group (cholesteryl moieties) were also grafted onto PAA. The polymers were characterized with elemental analysis, NMR and FTIR spectroscopy. All polymers formed self‐assemblies by probe sonication in water with sizes ranging from 120 to 199 nm and TEM images showed the presence of spherical particles. The critical aggregation concentration (CAC) varied from 0.093 to 1.5 mg ml?1 depending on the type of hydrophobic pendant groups. The Cholesteryl and Dansyl polymers showed the presence of one CAC while the Fmoc and Naphth grafted polymers revealed the presence of two CACs. The first CAC observed was possibly due to intermolecular aggregation while the second CAC at the higher polymer concentration was the result of excimer formation revealed by their fluorescent spectra. We reasoned that Naphth and Fmoc aromatic pendant groups possess a flat stereochemistry, thus allowing ππ stacking at higher concentrations. The presence of the N‐dimethylamino group in the Dansyl moiety gives rise to a 3D structure, thus hindering any stacking. The understanding of the supramolecular assemblies formed by these fluorescent amphiphilic polymers will aid in the engineering of advanced materials with superior functionality for biomedical applications. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

12.
Two coordination polymers with 5-aminoisophthalic acid (H2aip), [Ni(μ-aip)(H2O)2(tmeda)]n (1) and {H2dap[Zn2(μ-aip)(μ3-aip)2]?9H2O}n (2) (H2aip = 5-aminoisophthalic acid, tmeda = N,N,N′-N′-tetramethylethylenediamine, dap = 1,3-diaminopropane) have been synthesized. Elemental and thermal analyses, magnetic susceptibilities, IR, AAS, mass and UV–vis spectroscopic studies have been performed to characterize the compounds. Nickel(II) has octahedral geometry by two oxygens of different carboxylates, bidentate, tmeda as bidentate chelating and two water ligands. Zn(II) has tetrahedral geometry by three oxygens of different carboxylate groups and one nitrogen by amine of aip. 1 crystallizes in the orthorhombic crystal system with space group Pccn and 2 in monoclinic crystal system with space group P21/c. Complex 2 exhibits photoluminescence properties in the solid state at room temperature. This study determined the susceptibility patterns of 1 and 2 against bacterial, yeast and mold micro-organisms. Antimicrobial activities were done on 12 different micro-organisms using the micro-dilution method. Tested microbial species were inhibited by 1 with a Minimum inhibitory concentrations (MIC) of 375–3000 μg mL?1. Compound 2 showed antimicrobial activities against tested micro-organisms with a MIC of 188–1500 μg mL?1. Compound 2 showed antibacterial activity against Legionella pneumophila sg1 375 μg mL?1 (MIC value).  相似文献   

13.
As an extension of our work on the elucidation of the mechanism and control of 3‐dimensional network formation in the free‐radical crosslinking polymerization and copolymerization of multivinyl compounds with the aim to molecularly design vinyl‐type network polymers, novel amphiphilic polymers were prepared as crosslinked polymer precursors. Thus, benzyl methacrylate, a nonpolar monomer, was copolymerized radically with 5 mol % of triicosaethylene glycol dimethacrylate [CH2C(CH3)CO(OCH2CH2)23OCOC(CH3)CH2], a polar monomer, in the presence of lauryl mercaptan as a chain transfer agent. The resulting prepolymers (i.e., vinyl‐type network‐polymer precursors or amphiphilic polymers) were characterized mainly by viscometry using t‐butylbenzene (t‐BB) and a t‐BB/MeOH (80/20) mixture as solvents. The viscosities in the t‐BB/MeOH (80/20) mixture were quite high compared with those in t‐BB, and completely reversed concentration dependencies were observed in the solvents. These are discussed by considering the difference in conformation and the shrinkage of polar, flexible polyoxyethylene units or the entanglement of nonpolar, rigid primary chains. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4396–4402, 2000  相似文献   

14.
Polymers containing side‐chain terpyridine ligands of well‐defined architectures and controllable molecular weights and molecular weight distributions are reported. These polymers were synthesized by the atom transfer radical polymerization (ATRP) of a newly synthesized terpyridine monomer with three functional initiators. The obtained polymers were characterized with 1H NMR and gel permeation chromatography techniques. The efficiency of the ATRP technique and the overall control of the molecular characteristics of the polymers were demonstrated by a kinetic study of the polymerization reaction. Subsequently, the ruthenium(III)/ruthenium(II) complexation chemistry was employed for the attachment of bis(dodecyloxy)‐functionalized terpyridine moieties onto each side 2,2′:6′,2″‐terpyridine unit of the main polymeric backbone. Thus, the grafting approach was successfully combined with the metal–ligand coordination chemistry for the preparation of highly soluble polymeric complexes. The resulting complexes were fully characterized by means of 1H NMR, gel permeation chromatography, and ultraviolet–visible spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4838–4848, 2005  相似文献   

15.
以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H2L1)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基)双(硫二基)二苯甲酸(H2L2)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物:{[Ni(L1)(H2O)4]·2H2O}n (1)、[Zn(L1)(DMA)2]n(2)和[Co(L2)(DMF)2]n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明:3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。  相似文献   

16.
Three 1H‐benzimidazole‐5‐carboxylate (Hbic)‐based coordination polymers, {[Ni(H2O)(Hbic)2] · 2H2O}n ( 1 ), {[Ni(H2O)2(Hbic)2] · 3H2O}n ( 2 ), and {[Co2(H2O)4(Hbic)4] · 4DMF · 3H2O}n ( 3 ) were obtained by reactions of the ligand H2bic and NiII or CoII salts in the presence of different structure directing molecules. They were structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermal stability, luminescent, and magnetic measurements. Structural analysis suggests that the three polymers exhibit a 2D (4, 4) layer for 1 and 1D linear double chains for both 2 and 3 due to the variable binding modes and the specific spatial orientation of the Hbic ligand towards the different paramagnetic metal ions, which were further aggregated into different 3D supramolecular architectures by popular hydrogen‐bonding interactions. Weak and comparable antiferromagnetic couplings mediating by Hbic bridge are observed between the neighboring spin carriers for 2 and 3 , respectively. Additionally, complexes 1 – 3 also display different luminescence emissions at room temperature due to the ligand‐to‐metal charge transfer.  相似文献   

17.
Two new coordination polymers, [Mn(dpa)(2,2′-bipy)] n (1) and [Ni(dpa)(2,2′-bipy)] n (2) (H2dpa = 3,4′-biphenyl-dicarboxylic acid, 2,2′-bipy = bipyridine), have been synthesized and structurally characterized by elemental analysis, IR, and X-ray diffraction. Single-crystal X-ray analyses revealed that 3,4′-diphenic acid acts as a bridging ligand, exhibiting rich coordination modes to link metal ions: μ 2η 1: η 1, μ 1η 1: η 1, and μ 1 –η 1: η 0. Compound 1 demonstrates a 1-D zigzag chain. Compound 2 is a 1-D helical chain. In 1 and 2, there exist intermolecular π–π stacking interactions and non-covalent interactions responsible for the stabilization of the supramolecular structure. In 1, the Mn(II) chains exhibit a weak antiferromagnetic interaction.  相似文献   

18.
The tadpole‐shaped amphiphilic copolymers with cyclic polystyrene as the head and a linear poly(N‐isopropylacrylamide) as the tail have been successfully synthesized by combination of reversible addition‐fragmentation chain transfer (RAFT) polymerization and “click” reaction. The synthesis involves two main steps: (1) preparation of a linear acetylene‐terminated PNIPAAM‐b‐PS with a side azido group anchored at the junction between two blocks; (2) intramolecular cyclization reaction to produce the cyclic PS block using “click” chemistry under high dilution. The structures, molecular weights, and molecular weight distributions of the resulted intermediates and the target polymers were characterized by their 1H NMR, FTIR, and gel permeation chromatography. The difference of surface property between tadpole‐shaped polymer and its linear precursor was observed, and the water contact angles on the former surface are larger than that of the latter surface. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2390–2401, 2008  相似文献   

19.
以羧酸配体2,2''-(1,4-亚苯基双(亚甲基))双(硫二基)二苯甲酸(H2L1)和2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基)双(硫二基)二苯甲酸(H2L2)分别与金属盐反应,通过溶剂热方法合成了3个配位聚合物:{[Ni(L1)(H2O)4]·2H2O}n1)、[Zn(L1)(DMA)2]n2)和[Co(L2)(DMF)2]n3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明:3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。  相似文献   

20.
在水热条件下合成了基于四氟对苯二甲酸的2个二维微孔配位聚合物{[Cd2(IP)2(tfBDC)2(H2O)2]·H2O}n1)和{[Mn2(IP)2(tfBDC)2(H2O)2]·H2O}n2)(tfBDC=2,3,5,6-四氟对苯二甲酸,IP=1-H-咪唑[4,5-f][1,10]-菲咯啉)。二维层状结构是44-网状结构,三维超分子结构是由氢键连接相邻的二维层状结构而形成的。2个配位聚合物均用元素分析、热重分析(TGA)、粉末衍射(PXRD)、红外光谱(FT-IR)进行了表征,且对配合物1的荧光性质进行了详细的分析。  相似文献   

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