Designed Monomers and Polymers最新文献

With the solvothermal reactions of flexible tetracarboxylic acid ligand with the Cd(II) and Ca(II) ions, we acquired a new heterometallic coordination polymer formulated as {[Cd₂Ca₂(L)₂(DMF)₂(H₂O)₇]·(DMF)·2(H₂O)}_n (1, H₄L is 5-(bis(4-carboxybenzyl)amino)isophthalic acid, DMF is N,N'-Dimethylformamide). Furthermore, the solids of 1 shows ligand-centered luminescence at room temperature. It not only evaluated the treatment and nursing application value on acute cerebral infarction, but also explored the related mechanism. Above of all, ELISA assay measured the content of the MMP-9 released into the cerebrospinal fluid, and the real time RT-PCR was implemented and the NF-κB activation in the brain tissue was measured.

Pluronic block copolymers have phase behavioural characteristics which are extensively studied for drug delivery applications. In this study, we explored hydrophilic pluronic F108 (HLB = 27), hydrophobic pluronic L81 (HLB = 2) and their mixed micelles acting as solubilising mediums for model drug aceclofenac. The drug solubilisation and interactions have been analysed using UV-visible spectroscopy, Fluorescence spectroscopy, Rheology studies, Fourier-transform infrared spectroscopy, Scanning electron microscope, Dynamic light scattering, Cloud point and partition coefficient measurements. The investigation from UV-spectrophotometry demonstrated that mixed pluronic entrapped greater number of aceclofenac molecules than both the neat pluronics at same concentration. Excimer formation was evidenced from fluorescence spectra with pyrene as a probe. The rheological studies showed difference in viscosity over low shear range. Studies on FTIR demonstrated probable bonding between the aceclofenac and mixed pluronic molecules. The DLS studies on mixed pluronic showed swelling of micellar diameter from 317.6 nm to 413.5 nm. Thermodynamic parameters of the above system revealed higher partition coefficient value for mixed pluronic and spontaneity in drug solubilisation. This study can be exploited to use a hydrophobic copolymeric micelle in mixed pluronic formulation for better drug solubilisation.

Due to the unique properties such as nontoxicity, biodegradability, availability from renewable resources, and cost-effectiveness, polysaccharides play a very important part in the science and technology field. The various chemically modified derivatives of these offer a wide range of high value-added in both food and non-food industries. Among the chemical modification, etherified polysaccharide is one of the most widespread derivatives by introducing an ether group which is commonly stable in both acidic and alkaline conditions. Hydroxyalkylation, alkylation, carboxymethylation, cationization, and cyanoethylation are some of the modifications commonly employed to prepare polysaccharides ethers derivatives. There also has been a growing tendency for creating new types of modification by combining the different means of chemical techniques. The correct determination of degree of substitution (DS)/molar substitution (MS) is crucially important. The objective of this article is to summarize developments in synthetic etherified polysaccharides, involving analytical methods for determination of MS/DS, measurement processes, and the associated mechanisms.

Polycarbosilanes have been considered as potential materials used in electronic packaging and circuit boards owing to their excellent low-dielectric performance. In this work, we prepared new hyperbranched carbosilane oligomers (HCBOs) which were functionalized by benzocyclobutene (BCB) groups. HCBOs can be thermally cured to produce transparent (HCBRs) with low dielectric constant and high thermostability.

Natural mucilages are auspicious biodegradable polymeric materials. The aim of the present research work was to elucidate the characteristics of quince mucilage-based polymeric network for sustained delivery of metprolol tartrate and its toxicity evaluation. Mucilage was extracted by hot water extraction, and characterization of quince mucilage was accomplished by using Fourier transform infrared (FTIR) spectroscopy. Different batches of quince mucilage polymeric network were prepared by free radical polymerization by utilizing varying ratios of quince mucilage, acrylamide and crosslinker. Degree of swelling depends on concentration of mucilage, monomer and also on crosslinking density of polymeric network. FTIR illustrates proficient grafting, and morphological (scanning electron microscopy) analysis signified porous design. Hence, quince mucilage-based design was encouraging for sustained delivery of metprolol tartrate and acute toxicity evaluation proved that mucilage-based network was safe for oral drug delivery system.

Electrochemical polymerization of aniline by a combination of ultrasonic waves and electrolysis of water was performed. This method involves three processes: 1) creation of O₂ micro bubbles produced by electrolysis of water on the anode side, 2) depolarization of the bubbles at the electrode surface via mechanical vibration using ultrasonic waves to diffuse ions in the electrolyte solution, and 3) progression of direct current (DC) electrochemical polymerization to yield a conductive polymer with fine pores on the surface. The diameter of the pores is on the micrometer scale and is similar in size to pollens. The combination of the electronic function of the conductive polymer and porous polymer surface can be applied as a method to collect allergens such as dust and flower pollens. Electrical adsorption and desorption of pollen was conducted with the porous polyaniline synthesized using a micro-bubble sonic-electrochemical preparation.

Density functional theory (DFT) and time-dependent DFT (TD-DFT) are used to investigate the ground- and excited-state properties of donor-acceptor-donor (D-A-D) monomers based on 3,6-carbazole (CB) combined with various-conjugated benzothiazole derivatives, using B3LYP and the 6-311 G basis set. To create nine D-A-D monomers for this investigation, nine (9) distinct acceptors were inserted at the C3 and C6 positions of carbazole. The impact of various electron-donor groups on structural, electrical, and optoelectronic properties is investigated. Our technique for developing novel donor monomers provides a theoretical framework for further optimizing the photovoltaic device's electrical, optical, and efficiency features. The HOMO and LUMO energies, bandgap, excited state, exciton binding energy, open-circuit voltage (V_OC) and absorption spectra were calculated. Our findings indicate that CB-TDP-CB and CB-SDP-CB monomers have an appropriate electronic structure for polymer solar cells.

This work describes the use of the breath figure (BF) method for the fabrication of photoactive porous polymer films and the characterization of their responsive to photo stimulus. The films incorporate self-assembled photoactive polymers and ZnS nanoparticles (NPs). The effect of both components on the optical and morphological properties of the films were analyzed. Films with a hexagonally ordered pattern were obtained. The photoactive polymer was prepared by grafting the photochromic component 1-(2-hydroxyethyl)-3,3-dimethylindoline-6-nitrobenzopyran (SP) to polystyrene-block-polymethacrylic acid (PS-b-PMMA). ZnS NPs were incorporated into the polymer solution, and the films were prepared using spin-coating on glass substrates before subjecting them to the BF method. The hollow footprints were obtained before introducing the ZnS NPs in order to maintain the necessary conditions for hexagonal film growth. Accordingly, the SEM micrographs of the films prepared in the presence of ZnS NPs displayed a loss in the pore arrangement as a consequence of the interaction between SP moiety and NPs. The light-emitting properties of films were characterized by blue and violet colors when exposed to UV light under fluorescence. Progress in the field of breath-figure formation and its application, such as exemplified in this work, leads to functional structures with suitable applications in chemistry and materials science. It is expected that such microstructured polymeric films will have interesting applications in photonic and optoelectronic devices.

The objective of this paper was to develop a PLGA carrier Ticagrelor sustained-release microspheres preparation, which was expected to continue to release Ticagrelor for 14 days with a high encapsulation rate. Ticagrelor microspheres were prepared successfully with average diameter of 7.31 µm, drug loading of 12.49 ± 0.32% and EE up to 79.09 ± 1.69%. In the release medium of PH7.4 PBS, the microspheres showed good drug release behavior in vitro. In vivo release results also showed that the sustained-release microspheres could effectively control drug release in vivo and maintain a relatively stable blood drug concentration for about 2 weeks. The results indicate that Ticagrelor sustained-release microspheres can be used for long-term treatment of acute coronary syndrome.

Natural collagen has good biocompatibility and ability to promote tissue regeneration and repair, but the poor mechanical properties and intolerance of degradation of natural collagen limit its applications in the biomedical field. In this research, we synthesized a skin wound repair hydrogel with good biological activity, high strength and excellent water absorption properties. Inspired by the theory of wet healing, dopamine was introduced into the side chain of the water-absorbing polymer polyglutamic acid to synthesize a cross-linking agent (PGAD) with both water absorption and cell adhesion ablities, and then it was introduced into collagen/polyvinyl alcohol (PVA-COL) system to form a double network hydrogel. Scanning electron microscope observation of the morphological characteristics of the hydrogel showed that after the introduction of PGAD, the hydrogel formed an obvious pore structure, and the swelling rate showed that the introduction of PGAD significantly improved the water absorption rate of the hydrogel.In addition, PVA-COL-PGAD hydrogel has good mechanical properties and water absorption behavior.In vitro experimental results revealed that the hydrogel has good biocompatibility. In vivo wound healing experiments showed that hydrogel can promote wound healing process.These results indicated that our hydrogel has great potential as a medical wound dressing.