Tetrahydrofuran Solution Research Articles

One-Pot, Open-Air Synthesis of Flexible and Degradable Multifunctional Polymer Composites with Adhesion, Water Resistance, Self-Healing, Facile Drug Loading, and Sustained Release Properties.

Developing proper wound management via wound dressings represents a global challenge. Ideal wound dressings shall encompass multiple integrated functionalities for variable, complex scenarios; however, this is challenging due to the complex molecular design and synthesis process. Herein, polymer composites, cross-linked poly(styrene oxide-co-hexaphenylcyclotrisiloxane)/crosslinked poly(hexaphenylcyclotrisiloxane) (cP(SO-co-HPCTS)/cPHPCTS) with multiple functionalities are prepared by a one-step, open-air method using catalytic ring-opening polymerization. The introduction of a mobile polymer cP(SO-co-HPCTS) endows the composite with good flexibility and self-healing properties at human body temperature. The hydrophobic groups in the main chain provide hydrophobicity and good water resistance, while the hydroxyl groups contained in the end groups enable good adhesion properties. Drugs can be efficiently loaded by blending and then sustainably release from the polymer composite. The material can rapidly degrade in a tetrahydrofuran solution of tetrabutylammonium fluoride due to its SiOSi bonds. The facile, one-step, open-air synthesis procedure and multiple functional properties integrated into the composites provide good prospects for their extensive application and batch production as wound dressing materials.

Photoluminescent supramolecular gels derived from phenylenediamine hydrochlorides.

Supramolecular gels are promising as chemosensors, drug delivery systems and oil gelators. The present paper deals with photoluminescent supramolecular gels derived from phenylenediamine hydrochlorides. N-(3,5-Diaminobenzoyl)-L-alanine dodecyl ester dihydrochlorides (1L) underwent gelation in tetrahydrofuran (THF) and CHCl3, but not in C1-C4 alcohols, dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF). Compound 1L emitted blue fluorescence in the sol state and green fluorescence in the gel state. A THF solution of 1L exhibited absorption and emission maxima at wavelengths 94-104 nm and 92-110 nm longer than those in other solvents, such as methanol and ethanol, that cause no gelation of 1L. Particles with hydrodynamic diameters around 13 nm were detected in a THF solution (c = 1.0 mM) of 1L. The gelation of 1L in THF and CHCl3, and the lack of gelation in MeOH were supported by molecular dynamics simulations and dynamic light scattering measurements. N-(3,5-Diaminobenzoyl)-L-alanine dodecyl ester (1L'), an HCl-free analogous compound of 1L, underwent no gelation in THF and CHCl3, indicating the necessity of the ammonium salt structure for gelation. The UV-vis absorption and photoluminescence spectroscopic peaks of 1L red-shifted upon aggregation, which was supported by TD-DFT calculations of monomeric and dimeric models of 1L.

Experimental measurements and thermodynamic modeling of hydrate dissociation conditions for CO2 + THF + MgCl2 + water systems

• Experimental hydrate dissociation conditions for (CO2 + THF + MgCl2 + Water) system are reported. • A thermodynamic model has been developed and its results are in acceptable agreement with the experimental data. • The addition of low-medium concentration THF to the system has a promotion effect. • The addition of MgCl2 has an inhibition effect In this study, experimental and thermodynamic modeling on hydrate dissociation conditions of CO 2 + water systems in the absence/presence of MgCl 2 + THF aqueous solutions at various concentrations were investigated. The ternary systems, including different aqueous solutions of tetrahydrofuran and magnesium chloride (0.05 mass fraction of MgCl 2 , 0.05 mass fraction of THF: solution A; 0.15 mass fraction of MgCl 2 , 0.05 mass fraction of THF: solution B; 0.05 mass fraction of MgCl 2 , 0.20 mass fraction of THF: solution C; 0.15 mass fraction of MgCl 2 , 0.20 mass fraction of THF: solution D) were conducted in the temperature range between 280.9 to 292.9 K and pressure ranges 0.92 to 3.89 MPa. An isochoric pressure–search method was applied to undertake all measurements. The results demonstrated that MgCl 2 acts as an inhibitor in all experiments, while THF acts as a promoter. Comparing mentioned data with the same system in the absence of MgCl 2 , a shift is observed toward the left in the equilibrium curve that this kind of shifting left is more observable at high pressures. In addition, a thermodynamic model was developed utilizing the Peng-Robinson equation of state with classical mixing rules and the UNIQUAC activity coefficient model to predict the equilibrium conditions of the aforementioned system. The model results implied a reasonable agreement with the experimental dissociation data with an average absolute deviation of pressure below 0.3%.

A general method for endowing hydrophobic nanoparticles with water dispersion abilities.

Inorganic nanoparticles with long-chain ligands are usually hydrophobic. However, simple and practical methods for converting hydrophobic nanoparticles to hydrophilic nanoparticles are still lacking. Herein, we developed a general method involving using dimercaptosuccinic acid (DMSA) for endowing hydrophobic nanoparticles with water dispersion abilities. By mixing a tetrahydrofuran solution of DMSA with a cyclohexane solution of hydrophobic nanoparticles, the long-chain ligands were replaced with DMSA, with the replacement due to the strong and broad-spectrum coordination abilities of sulphydryls and carboxyls. Four representative kinds of hydrophobic nanoparticles, namely Ag, NaGdF4, TiO2, and ZnS nanoparticles, were selected for verifying the performance of this DMSA-based modification method. Meanwhile, this method can also widen the applications of hydrophobic nanoparticles and facilitate their being subjected to further graft modifications. We hope that our research will increase the chances for applications of nanomaterials to be made.

The preparation of novel AIE fluorescent microspheres by dispersion polymerization

ABSTRACT An approach to prepare monodisperse polystyrene microspheres with aggregation-induced emission (AIE) characteristics has been developed which shows promising applications in fluorescence-encoding. The micron-sized, monodisperse polystyrene microspheres with AIE molecules were perfectly synthesized by two-stage dispersion polymerization. Fluorescent AIE monomer was synthesized by Suzuki reaction, confirmed by nuclear magnetic resonance (NMR). These AIE fluorogens (AIEgens) exhibited unique properties such as bright green emission in solid state and increased emission in tetrahydrofuran (THF) solution with the increase of water content. The influence of the AIE molecules concentration to microspheres synthesis was well investigated. The reaction conditions were optimized to obtain the functional polystyrene microspheres with a size distribution around 3%. The novel microspheres were characterized by scanning electron microscopy (SEM), confocal fluorescence microscope and flow cytometry. According to these results, two-stage dispersion polymerization was proved to be an efficient pathway for the preparation of AIE fluorescent and functionalized microspheres, which could be used in many biomedical industries.

The preparation of higher performance solid form of DATNBI based on rapid in-situ solvate-mediated phase transition mechanism

Using energetic materials (EMs) products with impure solid forms in practical application scenarios will lead to a series of serious consequences in terms of safety, mechanics, storage, detonation, and reliability properties. A novel approach to obtain the scarce and superior performance solid form of EMs was developed by the strategy of rapid in-situ solvate-mediated phase transformation, which is a promising and convenient method because of avoiding additional desolvating under specific external conditions and greatly reducing the risks in the production of EMs. In this strategy, the low sensitivity and highly energetic material 4,4′,5,5′-tetranitro-1H,1′H-[2,2′-biimidazole]-1,1′-diamine (DATNBI) was used as a model substance and its α-DATNBI that is hard to gain but with better performance was successfully prepared. Furthermore, a mechanism of this solvate-mediated method was studied by exploring the types of solute clusters and intermolecular interaction of DATNBI in the microscopic view. These molecular assembly modes were determined in solid and solvents employing X-ray diffraction and in-situ micro-Raman technique, as well as attenuated total reflectance-Fourier transform infrared spectra combined with density functional theory calculation, respectively. It is found that solute molecules tend to exist as solvated monomers resulting in the prior precipitation of solvate in saturated solution of tetrahydrofuran (THF). From the perspective of crystal structure and transformation energy, the solvates consisting of DATNBI and THF can easily transform to the scarce α form of DATNBI. This study proposes a new practical strategy for a specific solid form mediated by solvates-mediated phase transformation, which is particularly beneficial for the preparation of high-purity solid forms of EMs with better energy and safety properties but also helps us to understand the key role of solvates in the polymorph formation..

Physical Properties and Transmitted Sunlight of Polyvinyl Chloride/ZnO Nanocomposites Films

The optical properties of polyvinyl chloride (PVC) and PVC/Zinc Oxide (ZnO) films were considered with different amounts of ZnONPs (0.001, 0.002, 0.003, 0.004 and 0.005) g. Using a Tetrahydrofuran (THF) solution all films be prepared by casting method. XRD results showed the amorphous structure of PVC film and Hexagonal crystalline structure of ZnO NPs, PVC/ZnO nanocomposites appear as pattern of PVC films so the peaks of ZnO don’t appear in it. FESEM image of PVC, ZnO and structure of PVC/ZnO nanocomposites seems to have cluster aggregates in different size. FTIR spectra revealed that ZnONPs had no effect on the polymer structure as there are no covalent bonds between PVC and ZnO NPs. Increasing the amounts of ZnONPs was seen to improve the optical properties (Absorbance, absorption coefficient and extinction coefficient) for PVC polymer. PVC polymer transmittance and energy gap decreased from 5.25 eV to 4.98 eV with increasing the amounts of ZnO NPs in nanocomposites. The solar radiation intensity in Baghdad was measured at a rate of 1 hour for the pure PVC films and PVC/ZnONPs for seven consecutive days in a rate from 6 A.M. to 6 P.M. (13 h). As can be observed, all films have the same ratio of transmitted radiation strength to sunlight intensity for all hours and days.

Reaction of decabromodiphenyl ether with organo-modified clay-templated zero-valent iron in water-tetrahydrofuran solution: Nano- to micrometric scale effects

Smectite clay-templated nanoscale zero-valent iron (CZVI) was modified with tetramethylammonium (TMA), trimethylphenylammonium (TMPA) and hexadecyltrimethylammonium (HDTMA) to achieve organoclay-templated ZVI (OCZVI). The reactivity of various OCZVIs was evaluated on the basis of degradation of decabromodiphenyl ether (DBDE) in tetrahydrofuran (THF)-water binary solution. Characterization of OCZVI interlayer at nanometric scale indicated that the clay particles had the domains with three basal spacings in the THF/water solution. In the 50 % THF solution TMPA modification promoted the formation of the domains with a basal spacing at 1.56 nm, which could promote the degradation of DBDE. At the micrometric scale, in the 90 % THF solution TMA and TMPA modification tended to enhance the aggregation of OCZVI particles, while the HDTMA modification reduced the aggregation, and high percentage of modification yielded viscous gel structures. The relatively rapid sedimentation processes in 90 % THF solution (compared to that in 50 % THF solution) and formation gel structures could reduce the access of DBDE to the interlayer reactive nZVIs, and lead to the significant reduction in reaction rate. These results provide important insights to the organo-modification on clays which could alter their orientations and dispersion in organic-water binary solution to achieve the desired reactivity on confined clay surfaces.

Effects of Heavy Iodine Atoms and π-Expanded Conjugation on Charge Transfer Dynamics in Carboxylic Acid BODIPY Derivatives as Triplet Photosensitizers.

Borondipyrromethene (BODIPY) chromophores are composed of a functional-COOH group at meso position with or without a biphenyl ring, and their compounds with heavy iodine atoms at -2, -6 positions of the BODIPY indacene core were synthesized. The photophysical properties of the compounds were studied with steady-state absorption and fluorescence measurements. It was observed that the absorption band is significantly red-shifted, and fluorescence signals are quenched in the presence of iodine atoms. In addition to that, it was indicated that the biphenyl ring does not affect the spectral shifting in the absorption as well as fluorescence spectra. In an attempt to investigate the effect of π-expanded biphenyl moieties and heavy iodine atoms on charge transfer dynamics, femtosecond transient absorption spectroscopy measurements were carried out in the environment of the tetrahydrofuran (THF) solution. Based on the performed ultrafast pump-probe spectroscopy, BODIPY compounds with iodine atoms lead to intersystem crossing (ISC) and ISC rates were determined as 150 ps and 180 ps for iodine BODIPY compounds with and without π-expanded biphenyl moieties, respectively. According to the theoretical results, the charge transfer in the investigated compounds mostly appears to be intrinsic local excitations, corresponding to high photoluminescence efficiency. These experimental findings are useful for the design and study of the fundamental photochemistry of organic triplet photosensitizers.

A Phenylene‐Based Light‐Emitting Polymer: Atums Green

AbstractThis work synthesizes a green‐fluorescent conjugated polymer and performs basic photophysical characterization of this new material. Atums Green[1] is synthesized by a Suzuki cross‐coupling polymerization reaction between isostructural dibromo and diboronic acid monomers and is structurally characterized by nuclear magnetic resonance and gel permeation chromatography. The polymer consists of an alkoxy‐substituted 1,4‐bis((E)‐styryl)benzene repeating unit with molecular weight up to Mn = 50 kDa relative to polystyrene. Atums Green shows a strong green fluorescence maximized at ≈500 nm in chloroform and tetrahydrofuran solutions, with an absolute quantum efficiency as high as 98%. The photobleaching dynamics and time‐resolved photoluminescence (TRPL) are measured both in solutions and in solid films. Finally, solution‐based lasing is demonstrated in a bulk lasing cavity and in a cylindrical microcavity. Lasing emission is readily achieved in both formats, indicating that Atums Green has excellent emission characteristics, and further suggesting that it may present a viable green‐emitting conjugated polymer materials system for light emission applications.

Nonsymmetric [Pt(C^N*N'^C')] Complexes: Aggregation-Induced Emission in the Solid State and in Nanoparticles Tuned by Ligand Structure.

Five square-planar [Pt(C^N*N'^C')] complexes (Pt1-Pt5) with novel nonsymmetric tetradentate ligands (L1-L5) were synthesized and characterized. Varying the structure of the metalating aromatic systems result in substantial changes in photophysical properties and intermolecular interaction mode of the complexes in solution and in solid state. The complexes are strongly emissive in tetrahydrofuran solution, with the band maxima ranging from 560 to 690 nm. Three of these complexes (Pt1, Pt2, Pt4) afford nanospecies upon injection of their solution into water, which show aggregation-induced emission (AIE) with a strong red shift of emission bands. In the solid state, crystalline samples of these complexes demonstrate mechanochromism upon grinding with a bathochromic shift of the emission. DFT and TD-DFT computational analysis of monomeric Pt1-Pt5 in solution and model dimeric emitters formed through intermolecular interaction of Pt1, Pt2, Pt4 molecules allowed assignment of observed AIE to the 3 MMLCT excited states of Pt-Pt bonded aggregates of these complexes.

Highly Emissive Luminogens in Both Solution and Aggregate States

Highly Emissive Luminogens in Both Solution and Aggregate States

Enhanced formation kinetics of hydrates using 1,3-dioxolane, l-leucine, and β-cyclodextrin

As the cleanest fossil fuel, natural gas (NG) plays an important role in energy supply systems and the carbon cycle worldwide. However, given the rapid increase in NG demand, there exists a compelling need for more efficient NG storage and transportation technology. Recently, solidified natural gas (SNG) technology has received increasing attention because of its safety, low cost, and flexibility. In this work, tetrahydrofuran (THF) and 1,3-dioxolane (DIOX), two dual-effect promoters (kinetic and thermodynamic), were investigated for use in SNG technology. The promotion effect of environmentally friendly l-leucine and β-cyclodextrin as co-promoters was also examined. This is the first study to our knowledge of the synergistic effects of DIOX, l-leucine, and β-cyclodextrin on the kinetics of hydrate formation at a near ambient temperature. The results showed that the methane uptake in DIOX solution was 46.28% higher than that in THF solution under the same conditions, and DIOX is less harmful to the environment and the human body. This indicates that DIOX is more valuable for application than THF. l-leucine and β-cyclodextrin were both useful in enhancing hydrate formation kinetics, but l-leucine was more effective. T90 was reduced by l-leucine and β-cyclodextrin by a maximum of 42.08% and 28.67%, respectively. Rapid hydrate formation kinetics demanded a higher driving force, according to controlled experiments at a near ambient temperature with varied driving forces. Additionally, varied NaCl concentrations promoted hydrate nucleation while reducing the gas storage capacity. This work contributes to a safer, more stable, and environmentally friendly SNG technology at a close ambient temperature.

Photodeformable Azo Polymer Janus Particles Obtained upon Nonsolvent-Induced Phase Separation and Asynchronous Aggregation.

Photodeformable submicron Janus particles (JPs), containing an epoxy-based azo polymer (BP-AZ-CN) and poly(methyl methacrylate) (PMMA), were fabricated upon nonsolvent-induced phase separation. The formation of the JPs was induced by gradually adding deionized water into a tetrahydrofuran (THF) solution of both polymers. The results show that the two polymers start to precipitate from the solution at almost the same water content and immediately separate into two phases in each particle due to the strong incompatibility between the two components. After the nucleation, the sizes of the aggregates increase with increasing water content in the following growth stage. The amount of BP-AZ-CN molecules assembling into the aggregates is controlled by the water content in the medium, while the aggregation of PMMA molecules is a slow diffusion-controlled process due to the much higher molecular weight of this polymer. With a further increase in the water content in the dispersion medium, the swollen aggregates collapse to form JPs. Interestingly, when a dispersion with a water content of 50 vol % is diluted with a THF/H2O mixture with the same water content, the shapes of the JPs are significantly modified and vitrified after removal of THF through evaporation. By increasing the dilution multiples adopted to dilute the intermediate dispersions, JPs with more asymmetric shapes are obtained due to the enhanced asynchronous aggregation. Ternary phase diagrams calculated according to the Flory-Huggins theory provide a semi-quantitative description and rationalization of the phase separation behavior related to the thermodynamic factors. The differences in the transport behavior and aggregation dynamics of the two polymers are also proven to be critical for the formation of the asymmetric structures. Upon irradiation, the BP-AZ-CN compartments of JPs exhibit remarkable elongation along the electric vibrational direction of a linearly polarized laser beam at a wavelength of 488 nm.

Highly Sensitive, Ultrastretchable, and Degradable PCT-CNT Strain Sensor for Continuous Monitoring of Male Erectile Dysfunction

Male erectile dysfunction (ED) has been attracting significant attention due to its serious effect on emotional damage, heavy psychological blow, and life quality. Nevertheless, it is still a challenge to score and monitor ED more conveniently, comfortably, and in real-time with ease at home. Herein, a highly sensitive strain poly (CL-co-TOSUO) (PCT)-carbon nanotube (CNT) sensor with ultrastretchable and degradable ability was designed and fabricated. The proposed PCT-CNT exhibited excellent mechanical properties, its strain can reach up to 2368%, and its tensile strength is over 12 MPa. A fast degradation rate of the PCT-CNT could also be acquired, completely degrading in 8 h in a tetrahydrofuran solution at room temperature. It is worth emphasizing that the proposed PCT-CNT could be assembled as a wearable flexible sensor with practical application potential in male ED detection, which has an excellent signal response with the bending and stretching of the simulated module.

A Highly Sensitive Fibrous Luminescent Probe Based on Anthracene Triarylamine for Nitroaromatic Explosives

AbstractThe rapid, sensitive, and efficient detection of nitroaromatic explosives (NAEs) is extremely important for human health and public safety; however, it is still a big challenge, especially for the detection of trace amounts of explosive vapors. In this study, a small‐molecule luminescent probe of an anthracene triarylamine derivative was synthesized and employed as a highly efficient and sensitive sensor for the detection of NAEs, including 2,4‐dinitrotoluene (DNT), 4‐nitrotoluene (4‐NT), and nitrobenzene (NB). The fluorescence intensity varied linearly along with the concentration of NAEs in the diluted tetrahydrofuran solution. The KSV values (Stern‐Volmer equation coefficient) were 2457, 1735, and 1286 M−1 for DNT, 4‐NT, and NB, respectively (DNT>4‐NT>NB). Furthermore, polystyrene/LiCl/AnPh electrospun fibrous films were manufactured and proved to be efficient fluorescence sensors for NAEs vapor. This quenching can be ascribed to the photo‐induced electron transfer (PET) process between the AnPh probe and NAEs analytes. The large contact area between the nanofibers and analytes in the film also contributed to the efficient quenching effect. This work will stimulate the design of new fluorescent probes for electrospun fibrous NAEs sensors and pave the way for their applications in future practical fields of public safety control.

Towards Efficient Blue Delayed-Fluorescence Molecules by Modulating Torsion Angle Between Electron Donor and Acceptor

Towards Efficient Blue Delayed-Fluorescence Molecules by Modulating Torsion Angle Between Electron Donor and Acceptor

A Versatile Tetraphenylethene Derivative Bearing Excitation Wavelength Dependent Emission, Multistate Mechanochromism, Reversible Photochromism, and Circularly Polarized Luminescence and Its Applications in Multimodal Anticounterfeiting

A Versatile Tetraphenylethene Derivative Bearing Excitation Wavelength Dependent Emission, Multistate Mechanochromism, Reversible Photochromism, and Circularly Polarized Luminescence and Its Applications in Multimodal Anticounterfeiting

Synthesis, structure and reactivity of a boron-containing spirocycle carbanion

The crystal structure, electronic characteristic, as well as the formation process, and nucleophilic reactivity of an unexpected boron-containing carbanion are presented. Its structure consists of a discrete cation and a spirocycle structure, in which the sp 3 hybrid C7 atom connects the mesityl substituted oxaborole unit and the puckered anthracene moiety. • A novel boron-containing carbanion with distinct structural characteristics was synthesized, which was composed of a discrete [K(cryptand)] + ion and a spirocycle anion. • The formation and electronic structure of carbanion were explored through DFT calculations. • The nucleophilic reactivity of carbanion with some chlorosilane or halogenated alkanes in THF solution was evaluated. Carbanion ( 2 ) was synthesized by the deprotonation strategy through treatment of (2-(anthracen-9-yl)phenyl)(hydroxy)(mesityl)borane ( 1-H ) with KN(SiMe 3 ) 2 in the presence of [2,2,2]-cryptand in tetrahydrofuran (THF) solution followed by crystallization of the crude product from cooled THF. Its crystal structure and electronic properties are presented, as well as the formation process and nucleophilic reactivity with chlorosilane or halogenated alkanes.

Electrosynthesized nanostructured molecularly imprinted polymer for detecting diclofenac molecule

• Effective technique to generate nanostructured polymer on glassy carbon electrodes. • Micropatterned molecular imprinted polymer film for detecting diclofenac. • A cavity-confined electrochemical growth of PEDOT in the presence of DCF. • Simultaneous extraction of PS beads and DCF by dipping in THF solution at once. • A larger active surface decorated GC provides more accessible binding sites. This work describes the preparation and application of micropatterned molecular imprinting in conductive polymer film for the detection of diclofenac molecules. A fast and cost-effective technique for generating nanostructured polymer on glassy carbon electrode (GCE) by combining nanosphere lithography (NSL) and electrochemical polymerization is reported. Firstly, GCE is modified by a close-packed monolayer of polystyrene (PS) spheres sized 500 nm in diameter, which subsequently serves as a template for the electrochemical deposition of poly(3,4-ethylene dioxythiophene) (PEDOT) accompanied by diclofenac (DCF). The functional monomers of 3,4-ethylene dioxythiophene (EDOT) were electropolymerized in the presence of sodium diclofenac (DCF-Na) as a target molecule to prepare a molecularly imprinted polymer (MIP) electrode. After dissolving PS and DCF-templated molecules simultaneously in tetrahydrofuran (THF) solvent, the micropatterned structure of PEDOT is generated on the GCE surface. This as-prepared MIP surface is applied to test the recognition of DCF molecules in phosphate-buffered saline (PBS) solution. Good linearity of peak current recorded by differential pulse voltammograms (DVP) after exposure to different DCF concentrations was obtained with a limit of detection (LOD) of 77.5 nM. The sensitivity of the as-prepared MIP electrode is 5 times larger than that of the control electrode made by non-molecular imprinted polymer (NIP). It opens a pathway to significantly improve the sensitivity and the quality of conventional electrochemical sensors for the detection of Diclofenac.