Diamine Monomer Research Articles

Polymeric optoelectronic materials with low-voltage colorless-to-black electrochromic and AIE-activity electrofluorochromic dual-switching properties

In recent years, colorless-to-black electrochromic (EC) and electrofluorochromic (EFC) materials are attracting increasing interest for the fundamental scientific research and potential applications. In order to achieve multiple-response optoelectronic materials with better black conversion and solid-state fluorescence performance (black-color/emission dual-switchable materials), we adopted a novel design strategy to synthesis a diamine monomer named TPE-NH2, in which the π-core tetraphenylethene (TPE) connects with two oxidation centers. All the polyamides/polyimides based on this monomer exhibited good solubility, thermal stability and aggregation-induced emission (AIE) activity. Among these, polyamide 5a not only showed rare EC properties (colorless-to-black) with ultra-low voltage (0–0.75 V), high optical contrasts (up to 87.9% at 692 nm) and fast switching times (2.04/1.45 s) but also demonstrated high fluorescence properties with the introduction of TPE. In addition, polyamide 5a showed good continuous switching stability for EC property and acceptable stability for EFC property, which makes it a potential candidate in EC/EFC applications.

Thin-film composite nanofiltration membranes with high flux and dye rejection fabricated from disulfonated diamine monomer

Novel nanofiltration (NF) membranes with improved flux, dye rejection, high pH and temperature resistance were developed using a disulfonated diamine co-monomer, disodium-3-3′-disulfone-4-4′-dichlorodiphenylsulfone (S-DADPS). Thin film composite (TFC) NF membranes were fabricated on a porous polysulfone-based ultrafiltration support layer via the interfacial polymerization between trimesoyl chloride (TMC) in the organic phase and S-DADPS/piperazine (PIP) mixture in the aqueous phase. The effect of S-DADPS content was investigated on the structure and properties of fabricated TFC-NF membranes by varying the ratio between S-DADPS and PIP from 0/100 to 100/0 (w/w). The chemical structure, surface properties and the morphology of TFC-NF membranes were characterized by Fourier Transform Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), optical profilometry, contact angle, and zeta potential measurements. Salt and dye rejection behaviors of fabricated TFC-NF membranes were evaluated using 2000 ppm MgSO4 and NaCl solutions and 100 ppm Setazol Red and Reactive Orange 16 dyes, respectively. Dyes were filtrated in acidic, neutral and alkaline conditions for pH resistance tests. The temperature resistance of membranes was evaluated using pure water and dye solutions at 15 °C, 25 °C, and 40 °C. Among all TFC-NF membranes fabricated by varying the S-DADPS/PIP ratio, the membrane with an 80/20 ratio of S-DADPS/PIP resulted in superior properties such as increased water flux without considerable salt and dye rejection loss compared to the neat TFC-NF membrane without S-DADPS. In addition, the variation of S-DADPS/PIP ratio was demonstrated as a powerful tool to tune the balance of flux, separation and rejection performance of NF membranes for custom purification purposes.

Microporous polyimides with high surface area and CO2 selectivity fabricated from cross-linkable linear polyimides

Linear polyimides of intrinsic microporosity have been intensively investigated for gas separation due to their microporous structure and high surface area. The microporous structure in the linear polyimides of intrinsic microporosity comes from their contorted structure. Therefore, most linear polyimides without contorted structure do not have micropores. In this work, the microporous polyimides are constructed through the condensation of a cross-linkable dianhydride monomer with two novel nitrogen-rich diamine monomers and post crosslinking reaction. The linear polyimide precursors without contorted structure have the same main-chain structure. The introduction of crosslinked structure endow the crosslinked polyimides (PI-CLs) with microporous structure. The microporous structure in PI-CLs can be tuned by changing the substituents of the linear polyimide precursors. The PI-CLs have competitive CO2 uptake capacity (7.3–9.4 wt%) at 273 K and 1 bar. Particularly, the crosslinked polyimide containing trifluoromethyl groups (CF3-PI-CL) shows high CO2/N2 and CO2/CH4 selectivity (72 and 22) at 273 K, which are among the best results for reported porous materials. This work reveals that the introduction of crosslinked structure and changing substituents is an efficient method for constructing microporous polyimides with abundant micropores and excellent CO2 selective adsorption capacity. This method also has great potential for fabricating high-performance microporous polymers based on other linear polymers without rigid contorted structure.

The synthesis and characterization of fluorinated polyimides derived from 2′-methyl-1,4-bis-(4-amino-2-trifluoromethylphenoxy)benzene and various aromatic dianhydrides

The synthesis and characterization of pendant methyl fluorinated polyimides (5a–f) derived from fluorinated diamine monomer, 2′-methyl-1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (2) and several aromatic dianhydrides (3a–f) is described. The synthesis of new fluorinated diamine (2) and the precursor fluorinated dinitro compound (1) are also discussed. The presence of trifluoromethyl group in the backbone of the fluorinated polyimide exhibited better optical transparency, organic solubility, dielectric constant, moisture adsorption and maintained mechanical and thermal properties than trifluoromethyl-free analogs (5′a–f). The highly fluorinated polyimides 5f via chemical imidization exhibited the best organic solubility, highest optical properties (b* cutoff wavelength = 367 nm). In addition, the highly fluorinated polyimide via thermal imidization also displayed relative lower dielectric constants (3.06 at 1 MHz) and moisture adsorption (0.16%) than most fluorinated polyimides. The t-butyl and phenyl substituted fluorinate diamine analogs and their fluorinated polyimides were also compared and discussed on thermal and mechanical properties.

Synthesis and properties of soluble polyimides containing tert-butyl, ether linkages, and triphenylmethane units

A molecular theory design was carried out to synthesize a diamine monomer 1-(4-tert-butylphenyl)-1,1-bis[4-(4-aminophenoxy)] phenylethane containing tert-butyl, ether linkage, and triphenylmethane units. Then it was polymerized with several commercial aromatic dianhydrides, including diphenyl hexafluoroisopropylidene tetraic acid dianhydride (6FDA), diphenyl ether tetracarboxylic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and benzophenone tetraacid dianhydride (BTDA), via the conventional two-step method to afford a series of aromatic polyimides (PIs). The structure and properties of the polymer were characterized by Fourier transform infrared (FTIR) spectroscopy, solubility test, thermogravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, and tensile tests. The results showed that there were characteristic peaks of PI around 1776, 1720, and 1378 cm−1 in the FTIR spectra; 6FDA-, ODPA-, and BPDA-based PI are easily soluble in N-methylpyrrolidone (NMP), concentrated sulfuric acid, N,N-dimethylacetamide (DMAc), pyridine, Tetrahydrofuran (THF), Trichloromethane (CHCl3), and other common organic solvents showing excellent solubility. In a nitrogen atmosphere, the glass transition temperature of the PI films are between 246°C and 275°C, the temperature of 5% weight loss is above 501°C, and the residual mass fraction at 750°C is 53–61%. The mechanical properties range from 67.2 MPa to 88.6 MPa. In addition to the BTDA-based PI film, the other three types of PI have good transparency. The simultaneous introduction of tert-butyl, ether linkages, and triphenylmethane units has a synergistic effect, which greatly improves the solubility of PI and maintains good thermal stability, mechanical properties, and optical properties of PI at the same time.

Effect of Chemical Structure and Degree of Branching on the Stability of Proton Exchange Membranes Based on Sulfonated Polynaphthylimides.

Hydrolytic stability and oxidative stability are the core properties of sulfonated polynaphthylimides (SPIs) as proton exchange membranes. The chemical structure of SPIs directly influences the performance. Herein, three different series of branched SPIs were designed and prepared using 1,3,5-tris (2-trifluoromethyl-4-aminophenoxy) benzene as a trifunctional monomer and three non-sulfonated diamine monomers, such as 4,4′-oxydianiline (ODA), 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (6FODA), and 4,4′-(9-fluorenylidene)dianiline (BFDA). The effect of the chemical structure and degree of branching on SPIs properties is discussed. The results showed that by controlling the chemical structure and degree of branching, the chemical stability of SPIs changed significantly. SPI-6FODA with two ether linkages and a hydrophobic CF3 group has higher hydrolytic stability than SPI-ODA with only one ether linkage. In addition, with the increase of the introduced B3 monomer, the oxidation stability of SPI-6FODA has been greatly improved. We successfully synthesized SPIs with a high hydrolytic stability and oxidative stability.

A highly robust and water permeable thin film composite membranes for pressure retarded osmosis generating 26 W·m−2 at 21 bar

Herein, we fabricated two types of electrospun membrane using: 1) sulfonated poly (arylene ether sulfone), which needs chemical cross-linking to increase its mechanical strength, and 2) thermally rearranged poly (benzoxazole-co-imide), which is mechanically robust while requiring the hydrophilic coating. With a high porosity and low structure parameter of the support layer, two thin film composite (TFC) membranes were fabricated via interfacial polymerization on the support layer using 1,3,5-bezenetricarbonyl trichloride (TMC) and m-phenylene diamine (MPD) monomers. Chlorine modification using NaOCl solution was applied to two TFC membranes (denoted as XBPSH-TFC-Cl and XPBO-TFC-Cl, respectively) to improve water permeability (A) of the polyamide selective layer, while maintaining decent salt rejection values (R). As a result, the highly efficient XPBO-TFC-Cl achieved a peak power density of 26.6 W·m−2 at 21 bar using 1 M NaClaq and deionized (D.I.) water as draw and feed solutions, respectively. According to the modeling results, XPBO-TFC-Cl was less affected by the adverse phenomena (such as concentration polarization and reverse salt permeation), and showed lower performance reduction for various feed sources compared to XBPSH-TFC-Cl. These results demonstrate the potential of the next generation TFC membranes, which are commonly used for power generation and liquid separation.

Hydrogen bonding induces dual porous types with microporous and mesoporous covalent organic frameworks based on bicarbazole units

Although the topologies of covalent organic frameworks (COFs) can be controlled mainly by varying the symmetries of the building blocks condensed to form the structures, another approach is to change the structures of blocks but retain the same symmetries. The construction of a single COF featuring pores of different sizes from two symmetrical building blocks remains extremely difficult. In this paper, we report an investigation into the effect of hydrogen bonding on the topological regulation of two-dimensional COFs as a new approach for managing their properties. Our strategy involved introducing pristine and substituted diamine monomers—benzidine (BD) and 1,4-dihydroxybenzidine (DHBD)—into the skeleton of bicarbazole-based COFs. The constructed bicarbazole-based COFs, Cz-BD and Cz-DHBD, were designed using a (C 2 + C 2 ) geometry strategy and synthesized through Schiff-base condensations of bicarbazole-4CHO and the benzidine derivatives. The resulting COFs featured two different topologies: Cz-BD COF possessing a single type of pore having a tetragonal structure, and Cz-DHBD COF possessing a Kagome structure featuring two types of pores (one hexagonal and the other triangular with mesoporous and microporous structure, induced by intramolecular OH ⋯ N hydrogen bonding). These COFs exhibited high crystallinity, great thermal stability, and large surface areas, as well as synergistic structural effects and high-performance CO 2 uptake. • Cz-BD COF possessing a single type of pore having a tetragonal structure. • Cz-DHBD COF possessing a Kagome structure featuring two types of pores. • One hexagonal with mesoporous and the other triangular with microporous structure induced by intramolecular hydrogen bonding. • These COFs exhibited high crystallinity, thermal stability, and large surface areas, and high-performance CO 2 uptake.

Reactivity-controlled synthesis of A2 + B3 type soluble hyperbranched polymers from aromatic diamines and cyanuryl chloride via a coupled monomer method

High molecular weight hyperbranched poly(guanamine)s (hb-PGs) based on cyanuric chloride (CyC) with various aromatic diamine monomers were successfully prepared via a coupled monomer (CM) method. The reaction of a diamine (A2 type monomer) with CyC (B3 type monomer) solution at −20 °C resulted in the corresponding (AB2)x type soluble intermediate, whose reaction then proceeded with an additional diamine monomer resulting in two- or three-component hb-PG polymers. A thick film was successfully prepared from a hb-Poly(BisAAF-CyC-mPDA) polymer solution that exhibits the exceptionally high Tg of 325 °C (as determined by thermomechanical analysis (TMA)) compared with that of the linear-type PG (l-PG) polymer such as poly(anilinodichloro-s-triazine-BisAAF) (Tg =191 °C). This hb-PG is miscible with the l-PG to a desired extent. Thus, blended polymer films were prepared, and their Tg values were measured by TMA. The blended films with hb-PG weight fractions of 85 %, 90 %, and 95 % exhibit the Tgs of 201, 212, and 228 °C, respectively. Contrary to the homo l-PGs, the blended films still exhibit stiffness above Tg at temperatures up to 400 °C. This may suggest that the prepared hb-PG could play an effective roll in binding linear PG polymers to afford supramolecular networks with amino functions at the periphery.

Highly Soluble Polyimides Containing Di-tert-butylbenzene and Dimethyl Groups with Good Gas Separation Properties and Optical Transparency

A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups, 3,3′-dimethyl-4,4′-diaminophenyl-3″,5″-di-tert-butyltoluene, was successfully synthesized by a simple coupling reaction using 3,5-di-tert-butylbenzaldehyde and o-toluidine as starting materials. A series of novel polyimides (PI 3a–3c) with large pendant groups were prepared with the obtained diamine monomer and three different commercial aromatic dianhydrides (3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride) by one-step high temperature polycondensation. The prepared polyimides exhibited high solubility and good membrane forming ability: they could be dissolved not only in some high boiling solvents such as DMF, NMP, DMAc, and m-Cresol at room temperature, but also in some low boiling solvents such as CHCl3, CH2Cl2, and THF. Their solubility in most solvents could exceed 10 wt%, and the flexible membranes could be obtained by casting their solutions. The prepared membranes exhibited good gas separation properties. The permeability coefficients of PI 3c for CO2 and O2 were up to 124.6 and 42.8 barrer, respectively, and the selectivity coefficients for CO2/CH4 and O2/N2 were 14.7 and 3.3, respectively. The membranes had light color and good optical transmission. Their optical transmittance at 450 nm wavelength was in the range of 67%–79%, and the cutoff wavelength was in the range of 310–348 nm. They also had good thermal properties with glass transition temperature (Tg) values in the range of 264–302 °C. In addition, these membranes possessed good mechanical properties with tensile strength ranging between 77.8–87.4 MPa, initial modulus ranging between 1.69–1.82 GPa, and elongation at break ranging between 4.8%–6.1%.

Gas separation properties of aromatic polyimides with bulky groups. Comparison of experimental and simulated results

A series of new diamine monomers, with systematic variations in their chemical structure, by introducing various substituents onto the polymer backbone, have been made to react with two commercial dianhydrides: a very rigid one, pyromellitic dianhydride, (PMDA) and a more flexible one, 2,2′-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), to obtain a series of polyimide membranes with high fractional free volume (FFV), and their gas separation properties have been studied. In order to gain insight into the relationship between structure and gas separation properties of the polymers, a computer simulation of the polymers has been carried out, by a combination of molecular mechanics and molecular dynamics, to study the effect of the polymeric structure on the permeability and selectivity of the membranes. Moreover, the effect of the probe size on the accessible free volume, which cannot be experimentally determined, has been simulated and related with experimental gas separation parameters as permeability and selectivity. The use of FFV (that corresponds to a probe of zero-radius) cannot predict the behavior of several polymers, which have similar FFV values but different values of permeability and selectivity. However, simulation has permitted to correlate accurately permeability and selectivity with the accessible free volume to probes of different radii.

Synthesis and gas permeation properties of thermally rearranged poly(ether-benzoxazole)s with low rearrangement temperatures.

The diamine monomer, 9,9-bis[4-(4-amino-3-hydroxylphenoxy)phenyl] fluorene (bis-AHPPF) was successfully synthesized according to our modified method. A series of hydroxyl-containing poly(ether-imide)s (HPEIs) were prepared by polycondensation of the bis-AHPPF diamine with six kinds of dianhydrides, including 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA), 3,3′,4,4′-oxydiphthalic anhydride (ODPA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-(hexafluoroisopropylidine)diphtalic anhydride (6FDA) followed by thermal imidization. The corresponding thermally rearranged (TR) membranes were obtained by solid state thermal treatment at high temperature under a nitrogen atmosphere. The chemical structure, and physical, thermal and mechanical properties of the HPEI precursors were characterized. The effects of heat treatment temperature and dianhydrides on the gas transport properties of the poly(ether-benzoxazole) (PEBO) membranes were also investigated. It was found that these HPEIs showed excellent thermal and mechanical properties. All the HPEI precursors underwent thermal conversion in a N2 atmosphere with low rearrangement temperatures. The gas permeabilities of the PEBO membranes increased with the increase of thermal treatment temperature. When HPEI–6FDA was treated at 450 °C for 1 h, the H2, CO2, O2 and N2 permeabilities of the membrane reached 239.6, 196.04, 46.41 and 9.25 Barrers coupled with a O2/N2 selectivity of 5.02 and a CO2/N2 selectivity of 21.19. In six TR-PEBOs, PEBO–6FDA exhibited the lowest rearrangement temperature and largest gas permeabilities. Therefore, thermally rearranged membranes from bis-AHPPF-based HPEIs are expected to be promising materials for gas separation.

Novel poly(imide-ether)s based on xanthene and a corresponding composite reinforced with a GO grafted hyperbranched polymer: fabrication, characterization, and thermal, photophysical, antibacterial and chromium adsorption properties

High-performance polyimides (PIs) with ether linkages and trifluoromethyl (–CF3) groups based on xanthene were designed and synthesized via a polycondensation reaction of novel diamine monomers with available aromatic dianhydrides.

Synthesis and properties of fluorinated copolymerized polyimide films

Two series of fluorinated copolymerized polyimide films with different dianhydride ratios were prepared via the conventional two-step method by using 4,4-oxydianiline(ODA) as the diamine monomer, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride(6FDA), 4,4'-oxydiphthalic anhydride(ODPA) and 3,3',4,4'- biphenyl tetracarboxylic dianhydride(BPDA) as the dianhydride monomer in N, N-dimethylacetamide. With the increase of 6FDA in the proportion of dianhydride, the tensile strength of the polyimide film showed a decreasing trend. This work provided a high performance film. The mass retention rate at 800°C was above 50%. The glass transition temperatures of the two films were 260 °C and 275 °C. The storage modulus of the two were 1500 MPa and 1250 MPa. The loss modulus were 218.70 MPa and 120.74 MPa. The transmittance of the film was 71.43%. The transmittance of fluorinated copolymerized polyimide films were significantly improved in the visible region of ultraviolet light, indicating that the polyimide film with high transmittance, high tensile strength, high heat resistance and high storage modulus was successfully prepared. It had an excellent application prospect in the field of flexible display.

Synthesis and characterization of an aromatic diamine and its polyimides containing asymmetric large side groups

A novel aromatic diamine monomer with asymmetric large side group: 4-(2,4,6-trimethyl)phenoxy-1,3-diaminobenzene, was synthesized by a two-step organic reaction. The monomer was separately subjected to a one-step high-temperature polycondensation reaction with three commercial aromatic dianhydrides to obtain a series of polyimides. Their structures and properties were characterized and studied by FTIR, NMR, UV, TGA, DSC, etc. The obtained polyimides showed excellent solubility not only in high-boiling solvents such as NMP, DMAc, and DMF, but also in low-boiling solvents such as CHCl3 and CH2Cl2. Their tensile strength was in the range of 76.9–93.5 MPa, the elongation at break was between 4.8% and 7.3%, and the modulus of elasticity was in the range of 1.6–1.8 GPa. The obtained films exhibited good optical transparency, and the representative polyimide derived from 4,4′-oxydiphthalic dianhydride exhibited a light transmittance of more than 83% at a wavelength of 450 nm. Moreover, these polyimides also possessed good thermal properties. Their glass transition temperatures are between 285 °C and 345 °C, and the 10% weight loss temperature in air and nitrogen is above 463 °C, showing excellent thermal properties.

Novel polyimides containing flexible carbazole blocks with electrochromic and electrofluorescencechromic properties.

A series of polyimides (PIs) were prepared by polycondensation of a diamine monomer with five anhydrides (1,2,4,5-benzenetetracarboxylic anhydride (BTA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTD), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BTD), 4-[(1,3-dihydro-1,3-dioxo-5-isobenzofuranyl)oxy]-1,3-isobenzofurandione (DDII), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BPTD)), which have anodic electrochromic (EC) properties. These PIs not only show good solubility and thermal stability, but also demonstrate stable electrochemical oxidation behavior and good EC properties, and the highest retained electroactivity reaches 99% after 600 cycles. In addition, the series of PIs exhibit excellent electrofluorescencechromic (EFC) properties. Therefore, the novel materials will contribute to the application of EC or EFC displays in the future.

Polyamide nanofilms synthesized via controlled interfacial polymerization on a "jelly" surface.

A thermal-sensitive "jelly" was used to control the diffusion of a diamine monomer for synthesizing polyamide free-standing nanofilms with an adjustable thickness of 5-35 nm. The reduced reaction rate of the interfacial polymerization at the hexane-"jelly" interface made the synthesized nanofilms show high water permeation flux and suitable salt rejection, and they also have highly negative surface charges and fairly smooth surfaces.

Economic Sulfur Conversion to Functional Polythioamides through Catalyst-Free Multicomponent Polymerizations of Sulfur, Acids, and Amines.

Sulfur utilization is a global concern because of its abundant nature sources and the safety or environmental problems caused by its burning or oxidation during storage, while sulfur-containing polymers are popular materials in virtue of their fascinating properties such as metal coordination ability, high refractive indices, and semiconducting property. The synthesis of sulfur-containing polymers is challenging, especially directly from elemental sulfur. Herein, catalyst-free and scalable multicomponent polymerizations(MCPs) of all commercially available elemental sulfur, dicarboxylic acids, and diamines were reported to facilely construct 12 polythioamides with diverse and well-defined structures, high molecular weights (Mw's up to 86 200 g/mol), and excellent yields (up to 99%) from elemental sulfur. Besides commonly used aliphatic diamines, aromatic diamine monomers are also applicable to these multicomponent polymerizations, affording polythioamides with unique rigid structures and improved functionality as compared to those of the previously reported polythioamides. These polythioamides can be applied in gold recovery, which could extract a trace amount of Au3+ from practical acidic leaching solution of discarded electronic waste selectively, rapidly (1 min), sensitively (10 ppb), and efficiently (>99.99%) with high extraction capacity up to 0.60 g· Au3+/g to directly afford high-purity elemental gold after pyrolysis. The MCPs could make use of both abundantly existing sulfur waste and trace amounts of precious gold residue in electronic wastes, demonstrating their great potential in resource utilization.

Benzoquinone-Based Polyimide Derivatives as High-Capacity and Stable Organic Cathodes for Lithium-Ion Batteries.

Multicarbonyl polyimide derivatives were synthesized by a facial condensation polymerization of dianhydrides with a new diamine monomer containing a benzoquinone unit that was prepared according to the Michael addition reaction. The ingenious combination of dedicated carbonyl groups from the benzoquinone and dianhydride with an aniline structure linkage not only provided stable polymeric chains with a high number of carbonyl groups per unit but also guaranteed their large π-conjugated main chains, which is favorable to their long cycle life and fast kinetics. When explored as cathode materials for lithium-ion batteries, the polyimide derivatives based on naphthalic dianhydride delivered a reversible specific capacity of 145 mAh/g at 0.1 C, a high rate performance with a capacity of 108 mAh/g at 1 C, and an ultralong stable cyclic performance with a capacity retention of 80.3% after 1000 cycles at 0.5 C. Based on the theoretical calculations and the exploration of the electrochemical behaviors, sensible predictions for the reversible ion-insertion reaction of the as-prepared sample were proposed to deeply understand the charge storage mechanisms. Moreover, a stable solid electrolyte interphase film formed in the ether-based electrolyte was confirmed to improve the electrochemical properties.

Multipurpose conjugated block copolymers based on novel triphenylylamine derivatives and squaric acid for electrochromic and resistive memory devices

Here, we synthesized two kinds of novel conjugated block copolymers P1 and P2 by reacting squaric acid and three kinds of homemade diamine monomers. The polymers P1 and P2 can be dissolved in many normal organic solvents and form films by solution-cast method with high mechanical properties. In addition, when the 10% weight loss is selected as a reference point, the polymers P1 and P2 showed the thermal decomposition temperatures at around 309 and 312 °C, respectively. The polymer films exhibit high coloration efficiencies (CE) (262–282 cm2 C−1) and good cyclic stabilities. In addition, the ITO/polymer/Al sandwich memory devices exhibited non-volatile resistive switching behaviors with low write, erase voltages (more than −0.6 V and less than 3.1 V, respectively), good ON/OFF ratio (843 and 1435) and reliable cycling endurance (more than 30,000 cycles). These properties illustrate that the polymers could be considered as potential electrode materials for both electrochromic and resistive memory devices.