Search

To construct pH/temperature dual sensitive micelles as novel drug delivery carriers, the synthesis of two diblock copolymers mPEG113-PMCC9-(PMCC-DBO)27 and mPEG43-PMCC25-(PMCC-DHO)15 based on mPEG and polycarbonate modified by acid and liquid crystal groups is described. In aqueous solution, mPEG113-PMCC9-(PMCC-DBO)27 and mPEG43-PMCC25-(PMCC-DHO)15 could self-assemble to form nanospheres and vesicles at very low critical micelle concentration, respectively. Both nanospheres and vesicles were less than 100 nm in diameter and demonstrated high loading capacity of doxorubicin (DOX) through ionic interaction between the free carboxyl groups in PMCC segments and the amine groups in DOX. In vitro release studies indicated that the two copolymer micelles were capable of pH/temperature-triggered release of doxorubicin and without a significant initial burst release. Furthermore, MTT assays showed that the blank copolymer micelles were nontoxic, while the drug-loaded micelles exhibited potent cytotoxic activity towards HeLa cells. These pH/temperature responsive copolymer micelles provided a new strategy for constructing stimuli-responsive drug delivery carriers in chemotherapy.

In this study, a new tannic acid cross-linking cellulose/polyethyleneimine functionalized magnetic composite (MCP) as a biomass adsorbent of Hg(II) ions was prepared. The morphology and structure of MCP were characterized with FT-IR, TG, XRD, SEM and TEM. The effect of the different factors such as pH, contact time, initial Hg(II) ion concentration, and adsorption temperature on the adsorption behavior was investigated. The results showed that MCP exhibited an excellent selectivity and reutilization, fast removal rate, and very high adsorption capacity. The corresponding adsorption capacity and removal rate of could reach 99.00% and 247.51 mg/g when the pH value, adsorption time, Hg(II) ion concentration were 5, 180 min and 100 mg/L at 293 K. The kinetics followed the pseudo-second-order, which indicated that the adsorption behavior of MCP for Hg(II) ion belonged to the chemical adsorption process and external diffusion. The thermodynamic study showed that the adsorption process was a spontaneous and exothermic process. After the fifth adsorption-desorption experiment, it still had better adsorption performance and reutilization. All in all, MCP with highly stable and efficient, as well as excellent reusability will be a candidate for industry-level applications from wastewater with Hg(II) ions.

Poly(trimethylene carbonate-co-2, 2′-dimethyltrimethylene carbonate) [P(TMC-co-DTC)] with a molecular weight of about 150 kDa and different copolymer composition were synthesized by ring opening copolymerization of trimethylene carbonate (TMC) and 2, 2′-dimethyltrimethylene carbonate (DTC), using stannous octoate [Sn(Oct)2] as catalyst. The results of thermal properties investigation showed that the glass transition temperature (Tg) of P(TMC-co-DTC) elevated with the increase of DTC segments in the composition. Furthermore, the acquired P(TMC-co-DTC) presented high thermal stability and good flexibility. The in vitro enzymatic degradation of P(TMC-co-DTC) was carried out in the lipase solutions (from Thermomyces lanuginosus, ≥100,000 U/g). The results showed that P(TMC-co-DTC) exhibited much better form-stability and lower degradation rate than poly(trimethylene carbonate) (PTMC),and the higher the DTC content, the lower the degradation rate. Hence, the methylated-functionalization caused by the introduction of DTC segments was an effective strategy to control the degradation behavior of PTMC.

Stimulus-responsive nanosystem is a powerful method to improve the bioavailability and reduce the side effects of anticancer agents. In the present study, a customized dual pH-responsive micellar nanoplatform (DOX+LAP-M) based on polycarbonate-doxorubicin conjugate micelles was prepared to co-deliver the chemotherapeutic agent lapatinib for inhibiting tumor growth and metastasis. DOX+LAP-M micelles with spherical morphology had a size of ~112 nm and had an initial negative surface charge, which are favorable characteristics for long-term circulation in the blood. Once the micelles accumulated in tumor tissues, the intrinsic tumor extracellular acidity triggered the charge switch of DOX+LAP-M micelles from -1 to 9 mV, thereby facilitating cell internalization and tumor penetration. Subsequently, the pH-sensitive micellar core accelerated the release of doxorubicin and lapatinib in the acidic intracellular environment. DOX+LAP-M micelles effectively inhibited the proliferation, migration, and invasion of 4T1 cells in vitro; furthermore, the administration of DOX+LAP-M micelles in 4T1 xenograft-bearing mice suppressed solid tumor growth with an inhibitory rate of 90.2% and significantly decreased pulmonary metastatic nodules, without significant systemic toxicity. This multifunctional micellar system has high potential for clinical cancer therapy.

Photocatalytic degradation technology is an important and promising method for complete elimination of toxic organics. In this study, the photocatalytic degradation of acetochlor using α-Fe2O3 nanoparticles under H2O2/UV system was studied with UV-Vis spectrophotometer and GC MS. The degradation rate was investigated on the effects of α-Fe2O3 morphology and dosage, initial acetochlor concentration, solution pH, and H2O2 dosage. The results showed that photocatalytic degradation efficiency could reach 91% by α-Fe2O3 with 200 mg/L hollow morphology at an initial acetochlor concentration, pH value, and H2O2 dosage of 50 mg/L, 7 and 40 μL, respectively. The photocatalytic reaction mechanism and degradation process of acetochlor by α-Fe2O3 were investigated and the degradation pathway of acetochlor was proposed. The oxidative attack involves N C bond connecting the aromatic ring with side chain, the nitrogen-containing side chain, chlorinated aliphatic to produce 1-methyl-3-ving-benzene, allyl-methyl-amine and 1-chloro-2-ethoxy-ethane. These intermediate products could be further oxidized to NO3−, CO2 and H2O. These findings provide new insights for the photocatalytic degradation of organic pollutants in the using α-Fe2O3 nanoparticles to achieve pollutant degradation.

In recent years, industrial contaminants and especially organic pollutions have been threatening both environmental safety and human health. Particularly, dibutyl phthalate (DBP) has been considered as one of the major hazardous contaminants due to its widespread production and ecological toxicities. Consequently, reliable methods toward the efficient and environmentally benign degradation of DBP in wastewater would be very desirable. To this end, a novel magnetically separable porous TiO

Stimuli-responsive nanotechnology-mediated drug co-delivery system is a notable strategy to improve access of the systemically administered chemotherapeutics to the tumors. Herein, a tailor-made 2,3-dimethylmaleic-anhydride-poly(ethylene glycol)-e-poly-l-lysine-doxorubicin /lapatinib polymeric nanoplatform (DMMA-P-DOX/LAP) for synergistically eliminating breast cancer is developed by encapsulating lapatinib into dual-pH responsive charge switchable biopolymer-doxorubicin conjugate nanoparticles. The physicochemical properties of polymeric nanoparticles are conducive to their stable circulation in the physiological condition, but reverse the surface charge from negative to positive ultrasensitively in slightly acidic tumor microenvironment, facilitating cell internalization and deep tumor penetration. Subsequently, DOX and LAP are synchronously released into the cytoplasm in response to the significantly increased acidity of intracellular environment. As a result, the combination therapy by DMMA-P-DOX/LAP nanoparticles compels the solid tumors to contract significantly or even vanish completely in the MCF-7 tumor model, moreover, the structural composition with amino acid and bioinert PEG ensures the favorable biosecurity of the co-delivery system in vivo. This dual-pH responsive nanotechnology-mediated drug co-delivery system provides great potentials for safe and effective cancer therapy.

A magnetically separable 2D Rh/Fe3O4/g-C3N4-N catalyst has been synthesized for the catalytic transfer hydrogenation of nitroarenes to afford corresponding anilines. The highly dispersed Rh nanoparticles are the dominant active species. The reaction is second order for rhodium according to the kinetic study, and this means the activity of different Rh-containing catalyst can be precisely predicted and the active site contains two adjoining rhodium atoms. The strong interaction between Rh and Fe3O4 contributes to the catalytic performance, therefore the obtained Rh/Fe3O4/g-C3N4-N catalyst exhibits excellent catalytic activity and chemoselectivity for the reduction of various nitroaromatics, and the turnover frequencies (TOF) can reach as high as 12,666 h−1 for 4-nitrophenol. Moreover, this catalytic system is environmentally friendly because of its green solvent water and harmless byproducts (H2O and N2), and the catalyst shows outstanding stability and recyclability with at least 12 cycles.

In order to explore the effect of various functional groups on the mesomorphic properties, a series of menthol-based blue phase liquid crystal compounds (A, B1, B2, C1, C2, D1, D2) with various core structures in the molecules were synthesized. Their chemical structures and phase behavior were characterized with FT-IR, 1H NMR, differential scanning calorimeter (DSC) and polarizing optical microscopy (POM). The selective reflection and photoisomerization were investigated with ultraviolet/visible (UV/VIS) spectrometer. In our case, all BPLCs showed oily streak texture with selectively reflection and blue phase (BP), irrespective of the structure of mesogenic cores. This demonstrated that (−)‑menthol had high chirality, and via succinyloxy spacer group could drive molecules to arrangement in double twist cylinders of BP. The length-to-diameter ratio, the bridge bond in the aryl rings and the conjugate action in the mesogenic core had a significant effect on Tm, Ti and temperature range of BP. BPLC A without conjugated structure in three-benzene mesogenic core revealed a larger temperature range of BP than other BPLCs with conjugated structure.

A smectic liquid crystal polysiloxane containing cholesteryl groups (SLCP-NA) was synthesized and used as a new kind of β-nucleating agent to induce the formation of β-crystal in isotactic polypropylene (iPP). The nucleating ability of SLCP-NA was investigated using wide-angle X-ray diffraction and differential scanning calorimetry. The content of SLCP-NA and crystallization temperature could lead to substantial changes to crystallization behavior of iPP. As the SLCP-NA content and crystallization temperature increased, the relative content of β-crystal (Kβ) tended to first increase and then decrease. The Kβ value reached a maximum value of 66.3% when the mass fraction of SLCP-NA and the crystallization temperature were 0.2 wt% and 120 °C, respectively. In addition, the rheological behavior of the iPP/SLCP-NA blends was studied. Exhilaratingly, a little mass fraction of SLCP-NA was found to greatly improve the flow ability of the blends, and the melt flow rate increased from 2.9 g/10 min of pure iPP to 43.9 g/10 min of the iPP blend with 0.3 wt% SLCP-NA. Moreover, the addition of SLCP-NA could decrease temperature sensitivity and increase shear sensitivity.

Four new liquid crystal cyclic carbonate monomers M1–M4, with cholesteryl moiety and flexible spacer of different lengths, were synthesised through coupling reaction. The chemical structures, mesophase properties and thermal behaviour of the monomers were characterised with Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy (1H NMR), polarising optical microscopy, differential scanning calorimetry and X-ray diffraction. Based on these results, the relationship between the number of methylene groups into flexible chain and the mesomorphism of the monomers was investigated. It was found that all the monomers showed a focal conic texture of a smectic A phase and exhibited an interdigitated molecular arrangement. Moreover, the glass transition temperature and the isotropisation temperature of the monomers except M1 decreased, and the mesophase range narrowed as the number of methylene units into the flexible chain increased.

An amphiphilic liquid crystal (LC) block copolymer based on aliphatic polycarbonate with pendant cholesteryl groups was synthesized by the coupling reaction. The structure and LC properties of the obtained block copolymer were characterized using FT-IR, 1H NMR, DSC, POM and XRD. The results showed the copolymer exhibited broken focal conic texture and fan-shaped texture of a smectic A phase during the heating and cooling process. Moreover, this copolymer showed mesophase state below body temperature, and it would be promising candidate as self-assembly material for applications in drug delivery. In addition, the self-assembly, drug loading and release behavior of the LC copolymer were investigated with UV–vis, DLS and SEM. It was found that the initial copolymer concentration and the pH value had a critical influence on the self-assembly behavior and the particle size of the micelles. What's more, the drug release also presented a pH response and the drug-loaded copolymer micelles were stable.

Six three-arm star-shaped liquid crystals (LCs) based on chenodeoxycholic acid (CDCA), termed as G-BH, G-YD, G-FD, G-DJ, G-DZ and G-BX, respectively, have been synthesised. CDCA was used as the chi...

A series of non-symmetric liquid crystal (LC) dimers with the same chiral core 1,2-propanediol (PD) have been synthesised, termed as ABBA-PD-TFBA, PBBA-PD-TFBA, ABA-PD-TFBA, PBA-PD-TFBA and AA-PD-T...

In this study, we synthesized a series of new liquid crystal aliphatic block polycarbonates copolymers mPEG43-b-P(MCC-Cn)51 (n = 1–4) via the ring-opening polymerization, hydrogenation reduction and coupling reaction, which contained side functionalized cholesteryl groups and were different in the number of the flexible methylene groups. The chemical structures of the chiral compounds and copolymers obtained in this study were characterized by FT-IR and 1H NMR spectra, and the average molecular weights of the copolymers were investigated by average molecular weights gel permeation chromatographic (GPC). The polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to characterize the liquid crystal behavior. The relationship of the structure and phase behavior of the chiral compounds and copolymers influenced by spacer lengths was discussed. As a result, the chiral compounds with two methylene only showed a smectic A (SmA) phase, while those with more methylene showed a SmA phase and cholesteric phase. As the number of the flexible methylene groups increased, the corresponding melting temperature, the transition temperatures of LC phases and the isotropic temperature of chiral compounds all showed a decreasing trend, and mesophase temperature range narrowed. The polycarbonate copolymer with two methylene did not show mesomorphism, while the copolymers with longer spacer length seemed beneficial for the formation of mesophases at room temperature and revealed a smectic A phase with an interdigitated molecular arrangement on heating and cooling cycles. The results showed a decreased tendency toward the glass temperature, and an increased tendency toward isotropic temperature for the LC copolymers with an increase of the spacer length.

The intercrystalline interfaces have been proven vital in heterostructure catalysts. However, it is still challenging to generate specified heterointerfaces and to make clear the mechanism of a reaction on the interface. Herein, this work proposes a strategy of Fe-catalyzed cascade formation of heterointerfaces for comprehending the hydrogen evolution reaction (HER). In the pure solid-phase reaction system, Fe catalyzes the in situ conversion of MoO

Nowadays, water pollution caused by mercury(II) has been a burning problem for environment and human health. Therefore, it is urgent to develop new materials to remove mercury(II) ions from wastewater. Herein, copper sulfide (CuS) particles were loaded on the modified carbon black obtained from used tires to develop an efficient C/CuS adsorbent for removing of mercury(II) from aqueous solution. The structure and morphology of the C/CuS composite were characterized by FT-IR, TG, XRD, SEM, TEM and BET. The influence of several experimental factors such as pH, initial concentration, contact time and coexisting ions on the adsorbent C/CuS was studied. The experimental results showed that the adsorbent C/CuS exhibited high adsorption capacity, fast removal rate and excellent selectivity for mercury(II) ions. The removal rate and adsorption capacity of adsorbent C/CuS for mercury(II) ions reached 96.06% and 240.10 mg/g within 60 min. The coexisting cations had almost no competitive effect for removal of mercury(II). Adsorption process of C/CuS toward mercury(II) ions were in good agreement with the pseudo-second-order model, and the adsorption equilibrium data of adsorbent C/CuS were consistent with the Langmuir model. Finally, the waste adsorbent C/CuS/HgS (10mg) as a photocatalyst was used to degrade 20 mL of rhodamine B (20 mg/g), and the corresponding degradation rate was 84.56%.

A homologous series of new chiral liquid crystal compounds, M6BnB (n = 2, 4, 6, 8, 10, 12, 14, 16, 18), with varying length of n-alkoxy chains at one end, was formed by covalently linking a chiral (−)-menthyl with biphenyl-benzoate via adipoyloxy spacer group. A combination of analysis methods such as Fourier transform infrared, 1H NMR spectra, differential scanning calorimetry, polarised optical microscopy and X-ray diffraction was carried out to systematically investigate their phase structures and phase transition behaviours. The length of the flexible terminal alkoxy group has a profound influence on the clearing points (Tiso) and Tiso decrease with the increase of alkoxy chain (n). In addition, increasing the length of the terminal alkoxy group tends to narrow the temperature range of the N* phase and favour the development of chiral smectic C phase.

Four non-symmetric dimers containing mandelic acid as the chiral core have been synthesised, termed as QBMA-B, QBMA-BCN, QBMA-BBCN and QBBMA-BBCN, respectively. Chemical structures and liquid cryst...

Four multi-arm liquid crystals (LCs) based on chenodeoxycholic acid, termed as 2G-PD, 2G-IB, 2G-BD and 5G-GC, respectively, have been synthesised by convergent method, which nematic LC, 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoic acid, was used as side arm, and chenodeoxycholic acid (CDCA) was used as the first core, 1,2-propanediol (PD), isosorbide (IB), 4,4′-biphenyldiol (BD) and glucose (GC) were used as the second core, respectively. The first generation product, CDCA2EA, displayed cholesteric phase. The second generation products 2G-BD and 5G-GC displayed cholesteric phase, while 2G-PD and 2G-IB exhibited nematic phase. The multi-arm LC, 2G-IB, did not display cholesteric phase although the two cores were all chiral ones. The result indicated that chirality of the second core sometimes made the multi-arm LCs display nematic phase when cholesteric CDCA-derivative were introduced into the second core. Some attention should be paid on molecular conformation besides the introduction of chiral cores for multi-chiral-core LCs to obtain cholesteric phase.

To study structure-mesomorphism relationships of chiral materials based on menthol, a series of chiral compounds containing menthyl group were synthesized. Their chemical structures, formula, and t...

A series of new chiral liquid crystal (LC) intermediate compounds (LC-C1~LC-C4) containing diosgenyl groups and the corresponding cyclic LC aliphatic carbonate monomers (LC-M1~LC-M4) were synthesised to investigate the relationship between their structures and phase behaviour. The chemical structures of the compounds obtained in this study were characterised using FT-IR, 1H NMR and 13C NMR measurement. The phase behaviour and mesophase structure were investigated with polarising optical microscopy, differential scanning calorimetry and X-ray diffraction measurement. As a result, LC-C1 and LC-C2 showed focal conic texture of the choleteric phase, while LC-C3 and LC-C4 with longer spacer length showed fan-shaped texture of a smectic A phase. The monomers (LC-M1~LC-M4) all exhibited focal conic texture of the choleteric phase on heating and cooling cycles. Furthermore, the effect of the spacer length on phase behaviour of the LC compounds was discussed.

Main-chain biodegradable liquid crystal based on c diosgenyl end-capped poly(trimethylene carbonate) [Dios-(TMC)n] was investigated. The novel liquid crystal was synthesized through ring-opening po...

A series of side-chain cholesteric polysiloxanes (PQ) were synthesised with poly(methyl--hydrogeno)siloxane, cholesterol (4-allyoxybenzoate) (M1), and 4-hydroxyphenyl-4(allyloxy) phenylpropanoate (M2), 4-allyloxy-4 ‘-cyanobiphenyl (M3). Then azo-containing chiral liquid crystalline polymer (PZ) were synthesised with PQ and 4-(4-hexyloxyphenylazo) benzoic acid (M4) by esterifying catalysed by 4-dimethylaminopyridine which is a new synthetic way. The chemical structures of monomers and polymers were confirmed by conventional spectroscopic methods and test methods for liquid crystal properties. The photo-induced isomerisation of the polymer is investigated by UV–vis spectroscopy. Weight lost temperatures (5%) for all polymers were greater than 298°C. The results showed that the introducing of azo moieties makes the polymer more stable on thermo dynamics. The transition temperatures of the polymers PQ and PZ exhibited some regularity as the change of ingredients of polymers. PQ series showed Grandjean...

Herein, we present the results of our extensive investigations on the synthesis and phase behaviour of nine novel (−)-menthol-based chiral liquid crystal compounds. They possess three phenyl rings and substituted with (−)-menthyl and varying length of n-alkoxy chains at one end. With the aim of exploring the fundamental relationships between molecular structural features and thermal properties, nine terminal n-alkoxy groups from ethoxy to n-octadecaneloxy group in even numbers have been used. A detailed characterisation of their properties was carried out. The characterisation results clearly illustrate that all the series compounds show the thermodynamically stable phases; the shorter chain homologues display only the BPI and N* phases, and the middle ones exhibit BPI, N* and SA* phases while the longer chain members show the BPI, N* and SC* phases. Besides, the BPI appeared in a narrow temperature range because of their thermodynamic disruption. Temperature range of the N* phase narrows when the length of the n-alkoxy tail increases. The reflection peak is shifted towards short wavelength region with increasing temperature due to the winding of the chiral nematic helix in the N* phase. Furthermore, their inherent reflection peak intensities of reflections were gradually weakened.

Fenton reaction-mediated oncotherapy is an emerging strategy which uses iron ions to catalytically convert endogenous hydrogen peroxide into hydroxyl radicals, the most reactive oxygen species found in biology, for efficient cancer therapy. However, Fenton reaction efficiency in tumor tissue is typically limited due to restrictive conditions. One strategy to overcome this obstacle is to increase the temperature specifically at the tumor site. Herein, a tumor-targeting iron sponge (TTIS) nanocomposite based on graphdiyne oxide, which has a high affinity for iron is described. TTIS can accumulate in tumor tissue by decoration with a tumor-targeting polymer to enable tumor photoacoustic and magnetic resonance imaging. With its excellent photothermal conversion efficiency (37.5%), TTIS is an efficient photothermal therapy (PTT) agent. Moreover, the heat produced in the process of PTT can accelerate the release of iron ions from TTIS and simultaneously enhance the efficiency of the Fenton reaction, thus achieving a combined PTT and Fenton reaction-mediated cancer therapy. This work introduces a graphdiyne oxide-based iron sponge that exerts an enhanced antitumor effect through PTT and Fenton chemistry.

Graphdiyne has attracted much interest from researchers for their potential applications in energy storage, catalysis, and biomedical areas. As one of the derivatives of graphdiyne, graphdiyne quantum dots (GDQDs) may possess superior bioactivity due to active acetylene units. However, the biological application of biocompatible GDQDs have not been reported so far. Herein, GDQDs with uniform size and good crystallization were prepared via a classical solvothermal method. The GDQDs exhibit excitation- and pH-dependent fluorescence emission as well as superior photostability, demonstrating their potential for bioimaging. The GDQDs demonstrate efficient cellular uptake and cell imaging without induction of detectable cytotoxic effects in vitro. Systematical safety evaluation further confirmed good biocompatibility of the GDQDs in vivo. Our study preliminarily validates the application of the GDQDs in biomedicine and encourages more thorough studies for better realizing the potential of GDQDs.

Currently, magnetic mesoporous silica nanospheres have been employed widely as adsorbents due to their large surface area and easy recovery. Herein, the functionalized magnetic mesoporous silica/organic polymers nanocomposite (MMSP) was fabricated by the grafted poly(m-aminothiophenol) embedded the aminated magnetic mesoporous silica nanocomposite based on Fe3O4 magnetic core, which was shelled by mesoporous silica and further modified by (3-aminopropyl) triethoxysilane. The adsorption properties of as-developed MMSP were systematically explored by altering the experimental parameters. The results indicated that the adsorption capacity and removal percentage of the MMSP could reach 243.83 mg/g and 97.53% within only 10 min at pH 4.0, and the coexisting ions had no significant effect on the selective Hg(II) ions removal from aqueous solutions, meanwhile, the adsorbent recovered by a magnet still exhibited good adsorption performance after recycled 5 times. In addition, by analyzing experimental data, the adsorption process of Hg(II) ions belonged to spontaneous exothermic adsorption, and the possible adsorption mechanisms were proposed based on the pseudo-second-order model and Langmuir model. After adsorption study, the waste material adsorbed Hg(II) was developed as an efficient catalyst for transformation of phenylacetylene to acetophenone with yield of 97.06%. In this study, we designed an efficient and selective material for Hg(II) ions remove and provided a treatment of the post-adsorbed mercury adsorbent by converting the waste into an excellent catalyst, which reduced the economic and environmental impact from conventional adsorption techniques.

In this work, we developed a cheap and effective magnetic composite adsorbent (MSP) by introducing starch/polyethyleneimine to the surface of magnetic mesoporous silica. The prepared material was characterized by FT-IR, TG, XRD, SEM and TEM to determine its composition and morphology. Adsorption experiment showed that the removal rate of mercury(II) and adsorption capacity could reach 97.87% and 244.87 mg/g after 150 min. The kinetic study indicated that the adsorption data fitted well with the pseudo-second-order model, and the adsorption equilibrium data belonged to the Langmuir model. Meanwhile, the study of coexisting ions showed that MSP had a highly selective adsorption of mercury(II), and the adsorption capacity of the adsorbent after five times accounted for 91.27% of the initial adsorption capacity, which indicated magnetic nanomaterial manifested excellent selectivity and reutilization for mercury(II) adsorption. All in all, a feasible methods and cheap materials were implied to prepare a new magnetic composite adsorbent, and it will be a candidate for uptake of mercury(II) ions from industrial wastewater.

Blend films of Poly (trimethylene carbonate) (PTMC) homopolymers with different molecular weights were prepared. The in vitro enzymatic degradation tests were carried out in lipase solutions to investigate the effect of self-blending on the degradation performance of PTMC. It was observed that the mass loss decreased as the proportion of low molecular weight PTMC in the blend film increased. And the sample's mass loss with the mass ratio of PTMC334/PTMC57=1/16 reached almost 30% after seven weeks, which corresponded to the minimum degradation rate constant k value of 5.219. It is also indicated by the changes in weight as well as the macroscopic and microscopic morphology. Furthermore, during the degradation cycle, the thickness of the film also became thinner with the mass loss, confirming the surface erosion degradation mechanism of the PTMC blend films. The conclusion that PTMC does not produce acidic degradation products has also been confirmed. Finally, decreases in glass transition temperature (Tg) and thermal stability were found along with the film degraded, attributing to the accumulation of low molecular weight degradation products on the surface. In brief, the long-acting application of PTMC in biomedical fields could be satisfied by precisely tailoring the degradation properties via its self-blending with different molecular weights.

Although many strategies are contributed to improve hydrogel properties, enhancing highly self-healing behaviors and excellent mechanical properties of hydrogels are still intractable problems in today. Herein, we reported a strong hydrogel with highly efficient self-healing and robust mechanical properties base on the bulk polymerization method. In this work, the formation of the hydrogel is induced by the dense hydrogen bonds and the segment entanglement interactions, which facilitate the formation of network with excellent properties, including out of ordinary stability in a widely pH range and outstanding mechanical properties. The storage modulus and loss modulus of the obtained materials can be adjusted by the variation of the initiator ratio. Furthermore, the materials can be self-healing after 2 h at room temperature, without requiring any external stimuli. The swelling behaviors of the hydrogel can be modified by adjusting the initiator concentration, which further provides guidance for the manufacture of high-performance gels with precisely controllable mechanical behaviors.

Elemental sulfur, as a by-product of petroleum refining, is regarded as a solid waste stored in above-ground deposits due to limited existing applications, meanwhile, mercury contamination is one of the current environmental issues considering its high toxicity to the human, and how to safely dispose of hazardous waste adsorbents is still an unavoidable problem. This study addresses these need by utilizing sulfur for preparation of a polysulfide complex material to capture Hg(II) and convert the Hg(II)-containing spent adsorbent into a catalyst. Initially, the mesoporous silica was prepared and functionalized by using diatomite and APTES, then, an in-situ preparation method was applied to obtain the amine-mesoporous silica/poly(m-aminothiophenol) nanocomposite (MAP), subsequently sulfur was copolymerized with MAP and vinylic-potato starch through inverse vulcanization, forming the sulfur crosslinked polymers composite cp(MAP-S-PS). Many characterizations were employed to determine the physicochemical structure and morphology of cp(MAP-S-PS). The adsorption study showed the cp(MAP-S-PS) exhibited the theoretical maximum adsorption capacity of 436.68 mg/g, good regeneration performance after 5 cycles and excellent selectivity between Hg(II) ions and common cations. Furthermore, the collected spent adsorbent cp(MAP-S-PS)/Hg(II) was reused as a catalyst for synthesis of acetophenone with 89% yield, and most of phenylacetylene derivatives were also transformed to corresponding acetophenone in good yields.

A new side cholesterol-functionalised liquid crystal (LC) copolymer based on aliphatic polycarbonate backbone was synthesised. The chemical structures of the block copolymers obtained in this study were characterised with Fourier Transform Infrared Spectroscopy (FT-IR) and Proton Nuclear Magnetic Resonance (1H NMR) spectra. Their thermal stability and phase behaviours were investigated with thermogravimetric analysis (TGA) measurements, differential scanning calorimetry, and polarising optical microscopy. The molecular organisation in the mesophase was studied by temperature-dependent X-ray diffraction (XRD). As a result, the block copolymer bearing side cholesteryl groups showed a glass transition at 15.8°C and a smectic A (SmA) to isotropic phase transition at 151.3°C on heating cycle. XRD indicated that the block LC copolymer showed an interdigitated molecular arrangement of the mesogenic units within the smectic layers. This partial bilayer structure was similar to the SmA phase formed by pola...

The synthesis of four new amphipathic copolymers with side functionalized-cholesterol based aliphatic polycarbonates is described through the ring-opening polymerization and coupling reaction. The chemical structures, liquid crystal (LC) behavior, and thermal stability of the chiral monomers and copolymers obtained in this study were characterized using Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, gel permeation chromatography (GPC), polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) measurements. The effect of the spacer length on the molecular interaction and mesophase of the chiral monomers and copolymers was investigated. It was found that chiral monomers with longer spacer seemed beneficial for the formation of mesophases, and the additional ordering on polymerization caused mesophases to be more ordered than for the corresponding monomers. The LC copolymers all revealed a smectic A phase with an interdigitated molecular arrangement. The results seemed to show a decreased tendency toward the glass transition temperature, and isotropic temperature for the LC copolymers by increasing the spacer length. In addition, four LC copolymers had a good thermal stability.

Main-chain biodegradable liquid crystal derived from cholesteryl derivative end-capped poly(trimethylene carbonate) was investigated. The novel liquid crystal was synthesised via ring-opening polymerisation of trimethylene carbonate initiated by cholesteryl derivative with an alkyl spacer and end primary hydroxyl group, without any catalyst. The chemical structure of resulting polymers was verified by 1H NMR. Liquid crystalline properties were validated by X-ray diffraction, differential scanning calorimetry, and polarising optical microscopy. The results showed that all the synthesised polymers Chol-(CH2)2-(TMC)n exhibited mesomorphism in particular temperature ranges because of the introduction of the cholesteryl derivative moiety.

The cholesteric polysiloxanes (P series) were obtained by reacting cholesteric monomer and phenolic hydroxyl monomer in different ratios with polysiloxanes. And then the chiral azo-containing polysiloxanes (AP series) were synthesized by esterifying P series members with the acryl acid of azo acid catalyzed by DMAP. The chemical structures and liquid crystal (LC) properties of the monomers and polymers were characterized by use of various experimental techniques such as FTIR, 1H-NMR, POM, DSC, TGA, XRD and ultraviolet-visible. Experimental results proved that obtained polymers were in accordance with the molecular design. The transition temperatures of the polymers exhibited a decreasing trend as the content of the cholesteric units increased and became higher by introducing the azo mesogenic core. The temperatures at which 5 % weight loss occurred are higher than 280 °C. P2–P6 showed blue Grandjean textures and exhibited selective reflection in the visible light region. AP series also possessed Grandjean textures, and the colors exhibited red shift with increasing content of azo moiety. On the heating cycles, when appropriate mechanical pressure was imposed on the polymers, AP2–AP6 selectively reflect visible light; however, there are no reflection peaks in the UV-Vis spectrum without the stimulation of mechanical pressure. All polymers exhibit left-handed optical activity due to having the same cholesteric group. The optical rotation direction of AP changes from left to right when increasing the UV irradiation time, and the photoresponsive behaviors of AP series are also investigated.

Two series of chiral mesogenic compounds derived from (−)-menthol with varying length of alkyl or alkoxy terminal groups respectively were designed and synthesised. Their chemical structures were c...

Four symmetric and non-symmetric chiral liquid crystal dimers containing trifluoromethyl groups, termed as TFBA-PD-TFBA, UEBBA-PD-TFBA, UEBA-PD-TFBA and UEA-PD-TFBA, respectively, have been synthesised and characterised. UEA-PD-TFBA exhibited chiral nematic phase, whereas the other three dimers displayed chiral smectic A phase. X-ray diffraction (XRD) has revealed the structure of the smectic A phase for TFBA-PD-TFBA to be intercalated, whereas that for UEBBA-PD-TFBA and UEBA-PD-TFBA to be monolayer and interdigitated, respectively. In addition, the weaker peak corresponding to a shorter layer spacing was observed for UEBBA-PD-TFBA and UEBA-PD-TFBA. Considering the results of XRD measurements and computer simulations, the structural model corresponding to the shorter layer spacing is assigned as horseshoe-like shape. The absence of smectic behaviour for UEA-PD-TFBA reveals that the weaker aromatic–aromatic interactions cannot stabilise the smectic A phase.

New cholesterol side-functionalised polycarbonate polymers were synthesised by the ring-opening homo- and copolymerisation reaction of the cyclic monomer cholesteryl 5-methyl-2-oxo-1,3-dioxane-5-carboxylate and d,l-lactide using Sn(Oct)2 as a catalyst. The chemical structures and average molecular weights of the cyclic monomer, homopolymer and block copolymers obtained in this study were characterised using FT-IR, 1H NMR and gel permeation chromatographic measurement. The mesomorphism and mesophase structure were investigated with polarising optical microscopy, differential scanning calorimetry and X-ray diffraction measurement. As a result, the homopolymer and block copolymers showed an enantiotropic smectic A (SmA) phase. With the concentration of the lactide segment increasing, the glass transition temperature and isotropic temperature of the corresponding block copolymer all decreased. In addition, XRD suggested that the homopolymer and two block copolymers showed the SmA double-layer packing ...

Herein, a novel magnetic network polymer composite (MCTP) was constructed by introducing the poly(m-aminothiophenol) and chitosan onto the magnetic-mesoporous nanoparticle under tannic acid as a crosslinking agent. Adsorption study indicated the removal rate and adsorption capacity of MCTP reached 98.16% and 245.49 mg/g within 15 min, meanwhile, it showed favorable recyclability after 5 cycles and excellent selectivity. The high-efficiency adsorption of Hg(II) is mainly dominated by chemical adsorption through forming stronger coordination bonds or Hg(II)-chelate complex between sulfur or nitrogen groups and Hg(II). Furthermore, the reutilization of toxic spent adsorbent was explored by converting MCTP/Hg(II) into a catalyst for synthesis of acetophenone with 99% yield, and most of phenylacetylene derivatives were transformed to corresponding acetophenone in excellent yields (>98%). Overall, this work not only reports a promising magnetic composite for treatment of Hg(II)-containing wastewater, but establishes the value-added utilization of waste adsorbent.

Many methods are used to improve the mechanical properties of hydrogels, but it is still challenging to generate comparable to natural hydrogels, let alone synchronously give it excellent self-healing properties. Herein, we synthesize a novel type of the aliphatic polycarbonate hydrogel with the above advantages. In this work, the ring-opening polymerization of 2-methyl-2-benzyloxy carbonyl propylene carbonate (MBC) and 1, 3-trimethylene carbonate (TMC) are initiated by the hydroxyl group of methoxy poly(ethylene glycol) (mPEG113, Mn = 5000). The effect of the TMC as flexible segments on the structure, mechanical properties, and self-healing behavior of the obtained materials is systematically studied. The swelling ratios of the obtained gels in water are enhanced as the content of the monomer TMC increases. The self-healing ability of the materials is drove by the hydrogen bonds and the hydrophobic associations to heal the fracture interfaces. The obtained gels exhibit outstanding mechanical properties and excellent ability of self-healing at room temperature. Both of these abilities can be adjusted by the variation of the TMC flexible segment. Thus, we provide a novel strategy for the fabrication of modified tough hydrogel, which will expand the modification field of hydrogels.

A novel catalytic system based on l -proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an l -proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield.

The weak mechanical property of hydrogels is a major obstacle to their extensive applications. Although many strategies are devoted to improve their mechanical properties, it is still a challenge to synthesize hydrogels with excellent mechanical properties and highly self-healing behaviors. Herein, we develop a novel aliphatic polycarbonate hydrogels with collaborative hydrogen bonds. In this work, the monomer 2-methyl-2-benzyloxy carbonyl propylene carbonate (MBC) is ring-opened by the hydroxyl group of methoxy poly(ethylene glycol) (mPEG113, Mn = 5000) based on the bulk polymerization approach. The monomer MBC as a hard segment contains abundant oxygen atoms and has a relatively high dynamic because of the steric effect of the benzene ring, which will facilitate further the formation of cooperative hydrogen bonds between the carbonyl and hydroxyl groups. The obtained hydrogels exhibited the excellent properties, such as outstanding mechanical properties, including higher storage modulus and loss modulus, it can be adjusted by the variation of the catalyst ratio. The brilliant ability of self-healing at room temperature that only takes 3 h to heal the fracture surface, without requiring any external stimuli. Thus, we provide a prospective strategy for the fabrication of split-new tough hydrogel with cooperative hydrogen bonding, which will increase the possibility of wide application of hydrogel.