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In this paper, a series of polyamide derivatives (PAMs) containing morpholine groups were prepared by Ugi polymerization from dialdehyde, diacid, N-(2-aminoethyl)-morpholine and isonitrile compounds as novel multi-responsive fluorescent sensors.

As an important metal element widely existing in nature and the human body, the simple and specific detection of Fe2+ ions has always been of interest.

The pristine carbon materials and traditional electrolytes can not fully meet the increasing practical demand for the high-performance of supercapacitors. Herein, a petal-like multicyclic polycondensate precursor (PCDP) was first prepared by Knoevenagel reaction and amine/aldehyde condensation between 3-aminorhodanine and p-phthalaldehyde. The subsequent activation of PCDP by KOH and final carbonization at different temperatures (600–900 ℃) was performed to get N/S-dual doped porous carbon (N/S-DDPCs) as electrode materials. For N/S-DDPC8 carbonized at 800 ℃, the highest specific surface area was measured as 2047 m2 g− 1, with a large number of interconnected microporous and mesoporous structures and the higher N and S contents of 3.57% and 2.31%, respectively. In addition, Zn(CF3SO3)2 aqueous electrolyte regulated by dimethyl oxalate (DMO) was fabricated in order to further enhance and stabilize the electrochemical performance for N/S-DDPCs. In contrast to the traditional Zn(CF3SO3)2 electrolyte, the energy density and power density of N/S-DDPC8 in DMO-regulated Zn(CF3SO3)2 electrolyte was significantly increased to 36.4 Wh kg− 1 from 11.7 Wh kg− 1 and to 642 W kg− 1 from 250 W kg− 1 at a current density of 0.5 A g− 1, respectively. Most excitedly, N/S-DDPC8-DMO-D can maintain 100% specific capacitance even after 10000 cycles, showing the superhigh electrochemical stability. In brief, N/S-dual doped porous N/S-DDPCs and DMO-regulated electrolyte prepared in this study provides a useful reference for the synergistically enhancing the electrochemical performance for the supercapacitors.

As one of the most investigated conducting polymers, polyaniline (PANI) is considered to be of practical use in many applications. In this study, two new ionic liquids, 1-methylimidazolium hydrogen sulfate ([Hmim]HSO4) and 1-methyl-3-n-butylimidazopersulfate ([C4mim]2S2O8), which were synthesized from 1-methylimidazole ([Hmim]), were used as solvent and dopant, oxidizer, respectively, for in situ polymerization of aniline. Because of the application of the unique structure of ionic liquid, we obtained the ionic liquid–doped polyaniline (IL-PANI) with high solubility (25 mg mL−1 in dimethyl sulfoxide (DMSO)). And by adjusting the ratio of [C4mim]2S2O8 to aniline monomer, the preferred PANI nanofibers could be controlled to form a three-dimensional porous structure. It was found that the ion/electron transport channels could be formed inside the 3D structure. Thus, the redox reactions could occur both at the surface and inside the PANI electrode. Electrochemical characterization showed that the fabricated PANI electrode exhibited a specific capacitance of 489 F g−1 at a current density of 0.5 A g−1. Also, the capacity retention rate reached up to 81% after 4000 cycles investigated at 2 A g−1. In addition, a high-energy density of 80.2 Wh kg−1 was measured when [Hmim]HSO4 was used as an electrolyte. Thus, the present work suggested a new strategy for fabricating high-performance PANI electrode for supercapacitor applications.

We developed a facile synthesis for a series of multifunctionalized polyesters by Passerini three-component polymerization (Passerini-3CP) in a “one-pot” method at room temperature using serial dicarboxylic acids, dialdehyde, and tert-butyl isocyanide as monomers. First, the effects of monomer feed ratio, monomer concentration, and different dicarboxylic acids involved in the polymerization were systematically investigated. The in situ FTIR and GPC measurements have suggested a step-growth mechanism for Passerini-3CP. Second, five succinic acid end-capped polyethylene glycols (S-PEGs) with different molecular weights of 400, 800, 1000, 2000, and 4000 g/mol were prepared and selected as dicarboxylic acids for the subsequent Passerini-3CP to fabricate the thermosensitive and biocompatible polyesters. Among the five resulting polyesters, four polyesters from S-PEG-400, S-PEG-800, S-PEG-1000, and S-PEG-2000 show reversible response to the external temperature, and the lower critical solution temperature (LCST...

In this investigation, we described a facile preparation of temperature/photo dual sensitive polymers (PGABs) by Ugi four-component polymerization (Ugi-4CP) at room temperature in “one-pot” method using glutaraldehyde, 4-amido-azobenzene, t-butyl isocyanide and carboxyl-end-capped polyethylene glycols (S-PEG) as monomers. PGABs were found to be reversibly sensitive to the temperature in salt solution, and their lower critical solution temperatures (LCST) can be tuned to the range of 17.2–68.4 °C by changing the structure of PGABs, sort and concentration of salt. The configuration transition of PGABs between cis-form and trans-form was reversibly induced by the alternating radiation at 365 and 254 nm. The rate and conversion of isomerization showed a remarkable dependence on the chemical structure of PGAB. By the photosensitivity, the LCST of PGAB-800 is further regulated in 1.0 °C change because of the hydrophilicity difference of cis-trans-azobenzene moiety. Through the combination of the thermosensitivity and photosensitivity, the particles of PGABs with nano/μm dimension were successfully controlled by the light radiation and temperature change.

Three-dimensional (3D) nanostructured conducting polymer hydrogels represent a group of high-performance electrochemical energy-storage materials. Here, we demonstrate a molecular self-assembly approach toward controlled synthesis of nanostructured polypyrrole (PPy) conducting hydrogels, which was "cross-linked" by a conjugated dopant molecule trypan blue (TB) to form a 3D network with controlled morphology. The protonated TB by ion bonding aligns the free sulfonic acid groups into a certain spatial structure. The sulfonic acid group and the PPy chain are arranged by a self-sorting mechanism to form a PPy nanofiber structure by electrostatic interaction and hydrogen bonding. It is found that PPy hydrogels doped with varying dopant concentrations and changing dopant molecules exhibited controllable morphology and tunable electrochemical properties. In addition, the conjugated TB dopants promoted interchain charge transport, resulting in higher electrical conductivity (3.3 S/cm) and pseudocapacitance for the TB-doped PPy, compared with PPy synthesized without TB. When used as supercapacitor electrodes, the TB-doped PPy hydrogel reaches maximal specific capacitance of 649 F/g at the current density 1 A/g. The result shows that PPy nanostructured hydrogels can be tuned for potential applications in next-generation energy-storage materials.

Self-healing hydrogels with biodegradability have great potential biomedical application in drug loading and delivery, wound dressing and tissue engineering. In this research, biodegradable hydrogels were designed from oxidized CMC (CMC-CHO) and PEO

In this paper, a new class of thermo-sensitive random polyurethanes (PGLDs) have been prepared by polymerization of L-lysineethyl ester diisocyanate with five homologous derivatives of ethylene glycols. The structure and properties of polyurethanes were characterized by various techniques. The molecular weight Mn and structure of polyurethanes are found to be particularly significant factors to their thermo-sensitivity. Four polyurethanes except poly(L-lysine ethyl ester diisocyanate-co-ethylene glycol) show a reversible phase transition at the lower critical solution temperature, which can be easily tuned in the range of 4–35°C by combination of the monomers. Unexpectedly, the increasing number of –CH2CH2O–units in the main-chain of polyurethanes apparently acts as the hydrophobicity in the solution. The catalyst-free-synthesized polyurethanes with Mn of about (1–2) × 104 g/mol responses to the external temperature. Stannous octoate-catalysted polyurethanes with Mn of (3–6) × 104 g/mol exhibit no thermo-sensitivity because of their strong intra/intermolecular interactions. In addition, the viability of HeLa cells in 0.01–100 μg/mL solution reached to 80% after 24 and 48 h of incubation, indicating no cytotoxicity for polyurethanes.

A random poly(L-alanine-co-L-lactic acid) (PAL) with excellent thermo-sensitivity and no cytotoxicity was synthesized by the structure-controlled polycondensation from natural L-alanine and L-lactic acid. Only those PALs in which the contents of L-alanine structural unit are rigidly controlled in the smaller range of 53–65% show a reversible lower critical solution temperature of 35–60°C. The change of secondary structure in poly(L-alanine) segments by the introduction of L-lactic acid structural unit plays a decisive role in regulating the thermo-sensitivity of PAL. The viability of HeLa cells exposed to PAL reaches up to 91–116% after incubation of 24 and 72 h, indicating no cytotoxicity. Furthermore, PAL can easily form curcumin-loaded nano-carriers through its thermo-sensitivity and self-assembly. The curcumin-loaded PAL nano-particles are observed to clearly internalize into the cells by confocal laser-scanning microscopy, and thus can be used as a potential nano-drug-carrier.

“Self-healable” materials can recover their structures and functions upon injury, which is extremely attractive for emerging biomedical applications. In this research, P(N-isopropyl acrylamide-co-4-formylphenyl acrylate) P(NIPAM-co-FPA) with a pendant benzaldehyde group though connection with a base-labile phenolic ester bond was designed, and polymer gels were prepared with PEO dihydrazide as a cross-linker. The polymer gels formed automatically by self-catalysis but their self-healing property was dependant on cross-linking density. The self-healing property of the polymer gel improved with decreasing cross-linking density based on decreasing FPA composition, increasing molecular weight of the cross-linker, and decreasing gelator concentration. Based on the reversibility of the acylhydrazone bond, the polymer gel showed gel–sol–gel transition by variation of acidity and group ratios. Furthermore, the gels could be degraded by Na2CO3 solutions because the phenolic ester bond is base-labile.

In this paper, a series of monomers (M1-M7) were facilely synthesized by Passerini reaction and the subsequent in-situ polymerization led to the formation of the conductive poly(indole/thiophene)s (P1-P7). Among P1-P7, it was found through the comparison that P7-P with a higher conjugated system exhibits an outstanding specific capacitance of 1170 F g−1 (scan rate 1 mV s−1), power density of 2614.4 W kg−1 and energy density of 56.5 Wh kg−1 (5 A g−1). The capacitance performance of P7-P complexed with Fe3+ system is further increased by 130 F g−1 because of the redox reaction of Fe3+. Using the chronoamperometry, the minimum detection limit of polymer P7-P for Fe3+ is 3 × 10−5 M. In summary, the facile synthesis of the conductive poly(indole/thiophene) polymers, their excellent energy storage and Fe3+ detection performance, open an opportunity for functional polymers in the energy storage and sensor applications.

Non-cytotoxicity or good biocompatibility is an essential requisite for the thermo-sensitive polymeric materials used in the biomedical fields. In this study, a new poly(N-acetyl-L-glutamic acid-co-lysine ester) (PGAL) with excellent thermo-sensitivity and biocompatibility is synthesized from natural lysine and glutamic acid. The chemical structures of the monomers and polymers are determined by 1H NMR, FTIR spectrum, and GPC. PGAL shows a reversible lower critical solution temperature (LCST) of 17.3–31.7 °C, and the thermo-sensitivity is affected by its molecular weight, structure, and concentration. The viability of HeLa cells in 0.01–10 μg/mL PGAL solution is found to be in a range of 98–110 % after 24, 48, and 72 h of incubation. To sum up, this new thermo-sensitive PGAL has excellent biocompatibility that makes it a promising material in the biomedical fields.

In this investigation, a group of poly(l-malic acid acetate-co-l-lysine ester)s (PMALs) with excellent thermo-sensitivity and non-cytotoxicity were prepared by an optimized synthetic route from natural l-malic acid and l-lysine. The structure and properties of PMALs including monomers were systematically characterized by FTIR, 1H NMR, UV, gel permeation chromatograph, scanning electron microscope, contact angle measurement, cell counting kit assess (CCK-8), and confocal laser scanning microscopy (CLSM). Three PMALs show a reversible lower critical solution temperature of 8–36 °C depending on their chemical structure. The contact angle measurement revealed a considerable discrepancy in the hydrophilicity/hydrophobicity of PMALs and further influence on their thermo-sensitivity. The viability of HeLa cells exposed to 0.2–100 μg/mL PMALs solution was found to be in a range 80–103% after 24, 48, and 72 h of incubation, indicating no cytotoxicity. Moreover, a spherical nanocarrier with core-shell structure was facilely fabricated via the thermo-sensitivity of PMALs and hydrophobicity of drug. CLSM observations manifested that the hydrophobic-curcumin-enwrapped nanocarriers can clearly internalize into the cellular inside. The sustained release of curcumin from nanocarriers in vitro provided a possibility of depressing fast hydrolytic degradation at physiological pH or other side-effects. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45984.