Mixture Of THF Research Articles

Synthesis, optical properties and self-assemblies of a new halogenated BODIPY dye with long alkoxy chain

A new boron-dipyrromethene (BODIPY) dye modified with two bromine atoms at the 2,6-positions and three hydrophobic p-(dodecyloxy)styryl groups at 3,5,8-positions was designed and synthesized. Its molecular structure was characterized by 1HNMR and MALDI-TOF-MS. The photophysical properties and aggregate behavior of dye 3 in solution were studied by UV–visible absorption and fluorescence spectroscopy. The dye 3 exhibited strong absorption and a high fluorescence quantum yield in different solvents. The self-assembly behaviors were investigated in THF and water mixtures, and the J-aggregates can be formed. Supramolecular self-assembly behavior of dye 3 was confirmed by temperature-dependent UV−Vis absorption. In addition, the self-assembly behavior of dye 3 in liquid-solid interface was studied using scanning tunneling microscopy (STM) and displays highly ordered linear arrangement on HOPG. The self-assembly processes are found to be adjusted by halogen bonding as well as π−π stacking.

Novel Anthracene and Carbazole Based Aggregation Induced Enhanced Emission Active Schiff Base as a Selective Sensor for Cu2+ ions.

In present work our group has synthesized two novel Schiff-bases, Di-Carbazole based Schiff-base (DB-1) and Di-Anthracene based Schiff-base (DB-2) using condensation reaction and characterized thorough different spectroscopic techniques such as mass spectrometry, IR spectroscopy, 1H and 13C NMR spectroscopy. Furthermore, the AIE(Aggregation induced emission) studies were done using water-THF mixture. As compared to pure THF, the DB-2 showed a 17.8-fold increase in fluorescence intensity with a bathochromic shift of 64nm in 80% water: THF mixture. For DB-1increase was seen at 70% water-THF combination. The analysis of the dynamic light scattering (DLS) further supported this excellent AIEE (Aggregation induced enhanced emission) characteristic. Furthermore, the spectrofluorometric techniques were used to examine the capacity of both Schiff bases to detect the heavy metals. It was discovered that only DB-1, with a detection limit of 2.4 × 10-8 M, was selective for the Cu2+ ion, whereas DB-2 had no sensing capability for metal ions. The Job's plot was used to determine the stoichiometry ratio of the DB-1 with Cu2+ to further examine the process. It was discovered that the ratio was 1:1 (DB-1:Cu2+). Additionally, the association constant of DB-1 for Cu2+ was 5.1 × 1011 M-1, demonstrating the excellent binding affinity of DB-1 for the Cu2+ ion.

Surface Engineering and Programmed Self-Assembly of Silica Nanoparticles with Controllable Polystyrene/Poly(4-vinybenzyl azide) Patches.

The programmed self-assembly of patchy nanoparticles (NPs) through a bottom-up approach is an efficient strategy for producing highly organized materials with a predetermined architecture. Herein, we report the preparation of di- and trivalent silica NPs with polystyrene (PS)/poly(4-vinylbenzyl azide) (PVBA) patches and assemble them in a THF mixture by lowering the solvent quality. Silica-PS/PVBA colloidal hybrid clusters were synthesized through the seeded growth emulsion copolymerization of styrene and 4-vinylbenzyl azide (VBA) in varying ratios. Subsequently, macromolecules on silica NPs originating from the copolymerization of growing PS or PVBA chains with the surface-grafted MMS compatibilizer are engineered by fine-tuning of polymer compositions or adjustment of solvent qualities. Moreover, multistage silica regrowth of tripod and tetrapod allowed a fine control of the patch-to-particle size ratio ranging from 0.69 to 1.54. Intriguingly, patchy silica NPs (1-, 2-, 3-PSNs) rather than hybrid clusters are successfully used as templates for multistep regrowth experiments, leading to the formation of silica NPs with a new morphology and size controllable PVBA/PS patches. Last but not least, combined with mesoscale dynamics simulations, the self-assembly kinetics of 2-PSN and 3-PSN into linear colloidal polymers and honeycomb-like lattices are studied. This work paves a new avenue for constructing colloidal polymers with a well-defined sequence and colloidal crystals with a predetermined architecture.

Anti-gravity drop motion and co-solute transport of hexamethyldisilane - tetrahydrofuran binary mixture on glass surface

Surface wettability modulation have garnered significant research interest due to diverse applications across fields ranging from microfluidics to biomedical devices. Surface wettability determined by factors like chemical composition and surface topography, influences a surface’s ability to attract or repel liquids. An essential phenomenon within surface wettability is the ability of droplets to move against gravity, known as uphill motion. This motion is particularly important in microfluidic devices requiring precise droplet control. Creating a surface with tuneable wettability supporting uphill motion is critical for optimizing device design. In this work, we proposed a simple and effective way to achieve tetrahydrofuran droplet self-running horizontally and sliding uphill without any other external force. We have used a complete wetting glass surface onto which binary non-aqueous THF drop containing hexamethyldisilane (HMDS) demonstrated uphill drop motion with tilted angle of ∼ 10°. This binary drop mixture of volatile THF and HMDS with various concentrations demonstrated self-propulsion on both the horizontal and tilted surfaces. We also examined the transport of an additional solute utilizing the binary mixture of HMDS-THF. The droplet motion against the gravity was achieved by gradient in solute concentration-based Marangoni stress. The potential applications of droplet motion against gravity on tilted surfaces span various domains. It can be harnessed for self-cleaning surfaces, microfluidic designs, and controlled liquid transport systems.

Simple Donor-π-Acceptor Compounds Exhibiting Aggregation-Induced Emission as Hidden Fingerprints Detecting Agents.

Latent fingerprints are a significant carrier of information for a court expert. To detect this type of forensic trace, what is necessary is a method that is easy to use, compact, and versatile. The research aimed to investigate the physicochemical properties of luminescent substances of donor-π-acceptor systems in terms of their potential use in detecting hidden fingerprints. During the research, a group of fluorene compounds consisting of the (-CH=C(CN)(COOR)) moiety was designed and successfully synthesized. The optical, electrochemical, and aggregation-induced emission properties were studied. The aggregation-induced emission of compounds has been studied in the mixture of THF (as a good solvent) and water (as a poor solvent) with different water fractions ranging from 0% to 99%. Due to the molecular structure, substances showed different affinities to organic traces. As a result, it was noticed that all compounds showed the AIE phenomenon, while during tests on latent fingerprints, it was observed that two substances had particularly forward-looking features in this field.

Intrinsically flame-retardant vanillin-based PU networks with self-healing and reprocessing performances

Conventional polyurethane (PU) networks fabricated from nonrenewable fossil resources are difficult to be recycled, reprocessed, and reshaped because of the permanent covalent cross-linked networks, and the flammability of PU networks limits their wide application. Herein, the novel polyols were synthesized from renewable vanillin and then reacted with hexamethylene diisocyanate (HDI) trimer to obtain versatile bio-based PU networks with dynamic disulfide and imine bonds for the first time. Obtain malleable PU networks that possess excellent reprocessability and self-healing performance, as well as superior fire resistance. The vanillin-based PU networks show a high T5d of ∼180 °C, high char yield of 23% at 800 °C, fast stress relaxation of ∼38 s at 80 °C, excellent scratch self-healing performance with approximately 100% healing efficiency at 120 °C for 90 min, outstanding flame retardancy with high LOI of ∼30% and UL-94 V0 rating. Additionally, the vanillin-based PU networks display excellent malleability with the activation energy (Ea) of 30.2–54.8 kJ•mol−1 due to dual dynamic bonds in the networks, which can be recycled in 60 min at 120 °C by hot pressing. Moreover, the vanillin-based PU networks with Schiff base can be degraded rapidly in the mixture of HCl and THF. Briefly, produced PU networks from abundant and renewable resources are significant examples to foster the development of versatile PU network materials.

Magnesium Complexes Supported by 6,6’‐Dimethylbiphenyl‐Bridged Salen Ligands: Synthesis, Characterization and Catalysis for rac‐Lactide Polymerization

AbstractA series of racemic 6,6’‐[(6,6’‐dimethyl‐[1,1’‐biphenyl]‐2,2’‐diyl)bis(nitrylomethilidyne)]‐bis(2‐R1‐4‐R2‐phenol) proligands (L1H2, R1=R2=Me; L2H2, R1=tBu, R2=Me; L3H2, R1=R2=cumyl; L4H2, R1=CPh3, R2=Me) were reacted with {Mg[N(SiMe3)2]2}2 to provide mononuclear and dinuclear magnesium complexes [L12Mg2] (1), L2–4Mg (2–4), {L1–3[MgN(SiMe3)2]2} (5–7). Complexes 3* and 4* in which each metal center is coordinated with a THF molecule were obtained when the corresponding crude complexes were recrystallized with a mixture of THF and n‐hexane. Similarly, the formation of THF coordinated structure 7* of the heteroleptic dinuclear complex 7 was identified. The molecular structures of complexes 3*, 6 and 7* were established by X‐ray single crystal diffraction studies, which show that mononuclear complex 3* possesses a five‐coordinated metal center adopting a distorted square pyramid configuration, the two metal centers of the dinuclear complex 6 are bridged by two phenoxy oxygen atoms and each has a four‐coordinated distorted tetrahedral configuration, and each metal center of the dinuclear complex 7* is still four‐coordinated upon the coordination of THF but without bridging to each other. All complexes were investigated for the ring‐opening polymerization (ROP) of rac‐lactide (rac‐LA) at 60 °C in toluene or tetrahydrofuran. Compared with the mononuclear counterparts, the dinuclear magnesium silylamido complexes showed significantly higher activities.

Synthesis, Characterization, Supramolecular Self-Assembly, and Organic Resistive Memory Applications of BODIPY Derivatives

A new class of BODIPY conjugated molecules modified with hydrophobic alkoxy chains or hydrophilic triethylene glycol chains has been designed, synthesized, and characterized. Supramolecular self-assembly behaviors of the compounds investigated by temperature-dependent ultraviolet–visible (UV–vis) absorption studies are found to display a cooperative growth mechanism with the formation of uniform and well-defined morphology of the aggregates in THF and water mixtures, which have been studied by transmission electron microscopy (TEM). Their self-assembly processes are found to be modulated by π–π stacking as well as hydrophobic interactions. The resistive memory devices fabricated with compounds 3 and 6 exhibit encouraging binary memory characteristics with low threshold voltages, high ON/OFF ratios, long retention times, and favorable stability.

Molecular torsion controls the excited state relaxation pathways of multibranched tetraphenylpyrazines: effect of substitution of morpholine vs. phenoxazine.

Multibranched donor-acceptor derivatives exhibiting desirable photophysical properties are efficiently used in optoelectronic devices, in which the excited state relaxation dynamics of the derivatives control the efficiency of the devices. Here, the effect of intramolecular torsion on the excited state relaxation dynamics of tetraphenylpyrazine (TPP) derivatives in non-polar (toluene) and polar (THF) solvents is investigated by substituting the electron donor of morpholine (TPP-4MOP) and phenoxazine (TPP-4PHO) leading to the planar and twisted configurations, respectively, using femtosecond and nanosecond transient absorption spectroscopy. In the steady state, TPP-4MOP showed feeble emission (ΦF ∼0.03) due to the weak donor by the delocalization of electron density supported by theoretical optimization. The TPP-4PHO exhibited strong emission (ΦF ∼0.18) in toluene compared to that in THF, in which it showed a large Stokes shift (∼9691 cm-1) with low fluorescence quantum yield (ΦF ∼0.01). The observation of large Stokes shifts, inherent nature and theoretical calculations of TPP-4PHO suggest the twisting of the dihedral angle between tetraphenylpyrazine and phenoxazine in the excited state leading to the twisted intramolecular charge transfer state (TICT). The femtosecond and nanosecond transient absorption and picosecond time-resolved emission spectra of TPP-4PHO revealed the signature of the existence of both the partial TICT and TICT states in THF leading to the triplet state. Whereas in the case of TPP-4MOP, the transient absorption spectra showed the formation of the triplet state from the local excited state without the involvement of the TICT state. Aggregation studies of TPP-4PHO in a THF and water mixture reflect the elimination of the TICT state by the restriction of intramolecular torsion in the aggregates leading to an increase of 12-fold of the fluorescence intensity along with shifting of the maximum towards the blue region. These studies revealed that the excited state relaxation pathways of the derivatives are controlled by polarity-dependent torsional motion.

Impact of the Morphology of Electrospun Lignin/Ethylcellulose Nanostructures on Their Capacity to Thicken Castor Oil.

This study reports on a novel strategy for manufacturing thickened gel-like castor oil formulations by dispersing electrospun lignin/ethylcellulose nanostructures. These thickened formulations were rheologically and tribologically evaluated with the aim of being proposed as alternative ecofriendly lubricating greases. Low-sulfonate kraft lignin (LSL) and ethylcellulose (EC) were dissolved in a DMAc:THF mixture at different concentrations (8, 10, and 15 wt.%) and LSL:EC ratios (50:50, 70:30, and 90:10) and subjected to electrospinning. The resulting electrospun nanostructures were morphologically characterized. EC acting as the cospinning polymer improved both LSL spinnability and the oil structuring ability. Solutions with a high lignin content achieved microsized particles connected by fibrils, whereas solutions with a high EC content (50:50 ratio) and LSL/EC total concentration (10 and 15 wt.%) yielded beaded or bead-free nanofibers, due to enhanced extensional viscoelastic properties and nonNewtonian characteristics. The gel-like properties of electrospun nanostructure dispersions in castor oil were strengthened with the nanostructure concentration and the EC:LSL ratio, as a result of the formation of a more interconnected fiber network. The oleodispersions studied exhibited a satisfactory frictional response in a tribological contact, with friction coefficient values that were comparable to those achieved with traditional lithium-lubricating greases.

Red-emitting IrIII(C^N)2(P-donor ligand)Cl-type complexes showing aggregation-induced phosphorescent emission (AIPE) behavior for both red and white OLEDs

Two red-emitting IrIII(C^N)2(P-donor ligand)Cl-type complexes bearing C^N ligands with carbazole functional group have been successfully prepared with different P-donor ligands of triphenylphosphine and triethylphosphine, respectively. The investigation of their phosphorescent behavior in the mixture of THF and water to reveal their aggregation induced phosphorescent emission (AIPE) ability, which is also indicated by their much higher phosphorescent quantum yield (ΦP) in doped film than those in the dilute solution. Mainly, their AIPE are induced by the blocked stretching motion of aromatic segments in C^N ligand and restrained the deformation of their coordinating skeletons. The AIPE complexes can possess AIE factor (αAIE) of ca. 7.4. In addition, the carbazole group can effectively promote hole transporting ability of the concerned AIPE emitters, which can benefit their electroluminescent ability. Hence, the IrIII(C^N)2(P-donor ligand)Cl-type complexes can show decent EL efficiencies in the solution-processed red-emitting organic Light-emitting diodes (OLEDs) with a maximum external quantum efficiency (ηext) of 8.5%, a maximum current efficiency (ηL) of 22.0 cd A−1 and a maximum power efficiency (ηP) of 15.9 lm W−1. Furthermore, as long-wavelength emitter, solution-processed white OLEDs (WOLEDs) have been constructed based on the red-emitting AIPE IrIII(C^N)2(P-donor ligand)Cl-type complexes, which can play critical role in achieving stable white electroluminescent spectra at high luminescence. The concerned WOLEDs can show attractive EL efficiencies of 6.6%, 23.7 cd A−1 and 16.0 lm W−1. All these results can provide valuable information for developing new AIPE materials with high EL ability.

Assessing the persistence of chalcogen bonds in solution with neural network potentials.

Non-covalent bonding patterns are commonly harvested as a design principle in the field of catalysis, supramolecular chemistry, and functional materials to name a few. Yet, their computational description generally neglects finite temperature and environment effects, which promote competing interactions and alter their static gas-phase properties. Recently, neural network potentials (NNPs) trained on density functional theory (DFT) data have become increasingly popular to simulate molecular phenomena in condensed phase with an accuracy comparable to ab initio methods. To date, most applications have centered on solid-state materials or fairly simple molecules made of a limited number of elements. Herein, we focus on the persistence and strength of chalcogen bonds involving a benzotelluradiazole in condensed phase. While the tellurium-containing heteroaromatic molecules are known to exhibit pronounced interactions with anions and lone pairs of different atoms, the relevance of competing intermolecular interactions, notably with the solvent, is complicated to monitor experimentally but also challenging to model at an accurate electronic structure level. Here, we train direct and baselined NNPs to reproduce hybrid DFT energies and forces in order to identify what the most prevalent non-covalent interactions occurring in a solute-Cl--THF mixture are. The simulations in explicit solvent highlight the clear competition with chalcogen bonds formed with the solvent and the short-range directionality of the interaction with direct consequences for the molecular properties in the solution. The comparison with other potentials (e.g., AMOEBA, direct NNP, and continuum solvent model) also demonstrates that baselined NNPs offer a reliable picture of the non-covalent interaction interplay occurring in solution.

Vanadium and nickel distributions in selective-separated n-heptane asphaltenes of heavy crude oils

Understanding vanadium and nickel distributions in asphaltene fractions have significant commercial importance throughout the petroleum value chain and the potential use of heavy feedstocks as a precursor of carbon-based materials, such as carbon fibers. This work extends our previous studies and aims to characterize volatile and non-volatile vanadium and nickel distributions by selective separation of n-heptane asphaltenes obtained from two Venezuelan heavy crude oils and the NIST Standard Reference Material (SRM) 8505. Asphaltenes were separated by extrography, i.e., adsorption on SiO2 and subsequent extraction with acetone, heptol (n-heptane/toluene 1:1 vol), and a mixture of toluene, THF, and methanol (TTM). The results suggest that their solubility and aggregation strongly correlate to a higher hydrogen deficiency and increased heteroatom levels. The qualitative analysis of the spent silica gel, containing irreversibly-adsorbed asphaltenes, by Light-Induced Breakdown Spectroscopy, suggests that regardless of the solvent power used during the extraction, strong chemisorbed Ni and V species remain on the SiO2, presumable associated with porphyrin molecules present on such feeds. High-Temperature Gas Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HTGC-ICP-MS) showed that vanadium and nickel compounds have boiling points starting at 1050 °F. Quantification of the V-content below 1300 °F for the Venezuelan crude 1 indicated that the acetone fraction contains a large amount of distillable vanadium (∼62 %wt.). Interestingly, whole/unfractionated asphaltenes revealed only 47% of distillable vanadium, which suggests that the extrography method can obtain asphaltene fractions with “improved” properties (weaker aggregation, increased solubility, and lower boiling points). The characterization by atmospheric pressure photoionization Fourier Transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) and HTGC-ICP-MS revealed that the acetone asphaltene fractions have a higher relative abundance of vanadyl porphyrins (with and without sulfur) than heptol and TTM.

Ni23Se12(PEt3)13] Revisited: Isolation and Characterization of [Ni23Se12Cl3(PEt3)10

The reaction of [Ni(1,5-COD)2] (1.0 equiv), PEt3 (0.04 equiv), SePEt3 (0.52 equiv), and [NiCl2(PEt3)2] (0.07 equiv) in a mixture of toluene and THF results in the formation of [Ni23Se12Cl3(PEt3)10] (1), which can be isolated in moderate yield after workup. Complex 1 was characterized by NMR spectroscopy, ESI-MS, and X-ray crystallography. This open-shell nanocluster features a central [Ni13]7+ anticuboctahedral kernel, which is encapsulated by a [Ni10(μ-Se)9Cl3]- shell, along with ten PEt3 ligands and three (μ4-Se)2- ligands. On the basis of our spectroscopic and crystallographic analysis, coupled with in situ spectroscopic monitoring, we believe that the previously reported nanocluster, [Ni23Se12(PEt3)13], is actually better formulated as [Ni23Se12Cl3(PEt3)10].

Polymerizable AEE-active Dye with Optical Activity for Fluorescent Nanoparticles Based on Phenothiazine: Synthesis, Self-assembly and Biological Imaging

In consideration of various advantages such as less harmful, higher sensitivity, and deeper imaging depth, etc, AIE materials with long-wave emission are attracting extensive attention in many fields of vascular visualization, organelle imaging, cells tracker, forensic detection, bioprobe and chemosensor, etc. In this paper, a novel fluorescent (R)-PVHMA monomer with chirality and aggregation-induced emission enhancement (AEE) characteristics was acquired through enzymatic transesterification reaction basing on phenothiazine, and its〖 [α]〗_D^(25 ℃) value was about -6.39° with 3.08eV energy level of HOMO and LUMO situations by the quantum calculations. Afterwards, a series of PEG-PVH1 and PEG-PVH2 copolymers with chirality feature were achieved through RAFT polymerization of the obtained (R)-PVHMA and PEGMA with various feed ratios. When the feed molar ratio of (R)-PVHMA increased to 29.6% from 21.5%, its actual molar fractions in the PEG-PVH1 and PEG-PVH2 copolymers accordingly increased to 25.7% from 18.1%. The molecular weight of PEG-PVH1 was about 2.2×104 with narrow PDI, and their kinetics estimation showed a first-order quasilinear procedure. In aqueous solution, the amphiphilic copolymers PEG-PVH could self-assembles into about 100 nm nano-particles. In a 90% water solution of H2O and THF mixture, the fluorescence intensity had the maximum value, and the emission wavelength presented at 580 and 630 nm. The investigation of cytotoxicity and cells uptake showed that PEG-PVH FONs had outstanding biocompatibility and excellent cells absorption effects, which have great potential in bioimaging application.

Unmasking latent thioesters under hydrophobic-compatible conditions.

Hydrophobic latent C-terminal thioesters were converted into thioesters, and were also coupled with cysteine in one-pot reactions, using conditions generally compatible with hydrophobic materials. The reaction conditions (ethanethiol and triethylamine in a mixture of DMF and THF) are compatible with acid-labile protecting groups (Boc/t-Bu) that are standard in Fmoc peptide synthesis.

Catalytic CO2 hydrosilylation with [Mn(CO)5Br] under mild reaction conditions

Carbon dioxide hydrosilylation with earth-abundant transition-metal catalysts is an attractive alternative for the design of greener and cost-effective synthetic strategies. Herein, simple [Mn(CO)5Br] is an efficient precatalyst in the hydrosilylation of carbon dioxide with Et3SiH under mild reaction conditions. Using THF as a solvent, triethylsilylformate Et3SiCH(O)O was obtained in 67% yield after 1 h at 50 °C and 4 bar of CO2 pressure. The selectivity of the reaction was tuned by changing the solvent to a mixture of THF and toluene producing bis(triethylsilyl)acetal (Et3SiO)2CH2 in 86% yield. The CO2 hydrosilylation was also effective at room temperature and atmospheric pressure using either THF or the mixture THF/toluene as the solvent resulting in high Et3SiH conversion (92%–99%) but with a decrease in the selectivity. Radical trapping experiments indicated the participation of radical species in the catalytic mechanism. To the best of our knowledge, this is the first report on CO2 hydrosilylation catalyzed by transition-metal radical intermediates.

Effect of the polydispersity on the dispersion of polymers through silicas having different morphologies (fully porous and core-shell particles and monoliths)

The effect of the polydispersity of polystyrenes on the dispersion through silicas having different morphologies (fully porous, core-shell particles and monoliths) was investigated. The heights equivalent to a theoretical plate (HETP) of those columns were measured for a small molecule (toluene) and a series of polystyrenes of different sizes in non-adsorbing conditions. The different contributions to the total HETP including polydispersity were determined experimentally. The longitudinal diffusion and the mass transfer resistance term were obtained from peak parking experiments. The eddy dispersion was obtained from models and experiments. The effect of polydispersity on the HETP values (Hpoly) can thus be calculated from the total HETP by substraction of the other contributions. The results were compared to the Knox model which surestimates the Hpoly values for porous and core-shell particles which is usually explained by an overestimation of the polydispersity index (PDI) given by the manufacturer. The PDI of two polymers (P02, Mw= 690 g.mol−1 and P03, Mw=1380 g.mol−1) was verified by liquid chromatography by separating each fraction of the polymer on the silica columns by using adsorbing conditions which are obtained with a mixture of heptane and THF. The PDI obtained are comparable to the PDI given by the manufacturer meaning that the assumptions made by Knox are not entirely valid. A direct method is proposed in this paper in order to determine Hpoly. In this method the excess of spreading as compared with a polymer with only one size corresponding to the average size is studied assuming the polymer size distribution is gaussian. The Hpoly values obtained by the direct method are comparable to the experimental values.

A Pyrene‐based Probe for Antimony with Special Excimer Fluorescence

Py‐IPH, a pyrene‐based fluorogen with good thermal and mechanical stability was simply prepared by the Schiff base reaction and applied in the detection of antimony. Py‐IPH presented special excimer fluorescence in the mixture of THF and water with 80 % of water, and exhibited perfect fluorescent response to antimony. The mechanism was demonstrated to be the increasing speed of the formation of pyrene excimers in the system owing to the coordination between antimony and IPH group in Py‐IPH. Moreover, based on the special interaction between Py‐IPH and antimony, it could distinguish antimony with other cations well with high specificity and selectivity.

Structure formation in pH-sensitive micro porous membrane from well-defined ethyl cellulose-g-PDEAEMA via non-solvent-induced phase separation process

To clarify the structure formation in pH-sensitive cellulose based micro porous membrane in non-solvent-induced phase separation process, first, a series of ethyl cellulose-graft-poly(2-(diethylamino)) ethyl methacrylate) (EC-g-PDEAEMA) with different graft density and graft length were synthesized via atom transfer radical polymerization (ATRP). The results of the micelles characterized by UV, Laser particle analysis and TEM indicated that the copolymer had pH responsive behavior and the increase of grafting density and grafting length led to the decrease of critical pH value. Furthermore, the morphology study of micro porous membrane via the NIPS process from mixture of THF and DMF indicated that the pores became smaller and more uniform with the increase of THF content and “open time”, and the most optimal preparation conditions was using EC0.2-g-PDEAEMA32 as the film-forming material and 75%THF/25%DMF (v/v) as solvent with the “open time” 1 min. What’s more, the membrane was responsive to pH stimulus in terms of water flux and demonstrated by scanning electron microscopy.