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A new kind of redox responsive nanoparticles was prepared through the modification and crosslinking reaction of xanthan gum. The nanoparticles had regular spherical shapes with diameters ranging fr...

The exfoliation of two-dimensional metal–organic frameworks (2D MOFs) to prepare few-layered MOF nanosheets (MONs) has been of great interest in recent years. In this work, an efficient and environmentally friendly liquid-exfoliation method is developed to produce stable and high-concentration dispersions of few-layered Zn2(bim)4 MONs. Bulk Zn2(bim)4 can be successfully delaminated in ionic liquid and water mixed solvents, where the ionic liquid acts both as solvent and surfactant. The highest exfoliation rate is up to 47% with a [Omim]Cl volume ratio of 50%. In addition, the prepared Zn2(bim)4 MONs can be easily dispersed in an aqueous solution and stabilized for more than 2 weeks. Zn2(bim)4 MONs are used as a fluorescent sensor to detect metal ions in water and exhibit enhanced sensing ability for Fe3+ than bulk MOFs. The highly dispersive nature after delamination and easily accessible active sites on Zn2(bim)4 MON surface are all in favor of its high-performance in sensing.

Hybrid nanocomposites based on UiO-66-NH2 and carboxyl-functionalized carbon nanotubes were developed in this study via different synthetic pathways. Combining them through interfacial in situ growth was beneficial for the better dispersity of UiO-66-NH2 in the CNTs@UiO-66-NH2 composite than physically mixing CNTs/UiO-66-NH2 and chemically bonded CNTs-CONH-UiO-66. Coordination between carboxyl groups of CNTs and zirconium ions resulted in the interfacial growth of UiO-66-NH2 on CNTs. Adsorption experiments showed that CNTs@UiO-66-NH2 exhibited the highest adsorption efficiency towards methyl orange (MO). The adsorption capacity of CNTs@UiO-66-NH2 was up to 392 mg g-1, which was 77.45% and 201.5% higher than those of CNTs-CONH-UiO-66 and CNTs/UiO-66-NH2 respectively. Moreover, CNTs@UiO-66-NH2 could selectively adsorb MO from the MO/MB mixture.

The novel nano-flocculants were synthesized through a conjugation of dodecylamine with partly oxidized sodium alginate. The structures of the flocculants were characterized by FTIR, 1HNMR, TGA, and EA. The flocculants possessed amphiphilic structures and formed nano-micelles through self-assembly in water. The nano-micelles showed rod-like shapes about 100 nm. Removal rates of the flocculants for Pb2+ and bisphenol A were determined under different conditions, showing the removal rates as high as 97.20% and 88.66% for Pb2+ and bisphenol A, respectively. The flocculation mechanisms were revealed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), respectively. Isotherm adsorption studies indicated that the flocculation for Pb2+ accorded with the Langmuir single-layer adsorption model, and for bisphenol A accorded with the Freundlich multi-layer adsorption model. The quasi-second-order kinetic model was suitable for describing the adsorption kinetics. The new nano-flocculant was a promising agent for removing both heavy metal ions and organic pollutants of wastewater.

The competitive adsorption of water restricts the practical performance of metal-organic frameworks (MOFs) for organic dye removal. Here, we paid attention to tuning the hydrophobicity of MOFs for dye adsorption. By introducing highly branched hydrocarbon chains, a super-hydrophobic MOF with a contact angle 158° is obtained using a post-synthetic pathway. At the same time, the crystallinity, thermostability can be well maintained, and the surface area is as high as 615 m2 g−1. The superhydrophobic MOFs exhibit improved dye adsorption efficiency, and more than 99% Rhodamine 6G can be adsorbed within 10 min while only 52% for the pristine one. Upon adsorption equilibrium, the adsorption capacity of the hydrophobic MOFs reaches 478 mg g−1, much higher than that of the pristine hydrophilic ones (243 mg g−1).

The polymeric micelles were prepared through a copolymerization of allyl polyethylene glycol (APEG) and N-isopropylacrylamide in the presence of 2-aminoethanethiol (AET), followed by a ring opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydride (BLG-NCA). Doxorubicin (DOX) as a model drug was covalently conjugated into the core of micelles via hydrazone bonds. The drug loading capacity could reach up to 15% with drug encapsulation efficiency of 80%. The pH/thermo sensitivities were observed in the process of in vitro drug release. The DOX-loaded micelles exhibited accelerated drug release behaviors in an acidic condition, and enhanced therapeutic efficacy was observed. Furthermore, the cytotoxicity of micelles against Hela and 3T3 cells was evaluated before and after drug loading. The DOX-loaded micelles showed strong cytotoxic activity to the cancer cells. But the blank micelles showed non-cytotoxicity. Therefore, the thermo/pH dual-responsive polymeric micelles have a promising future applied as a controlled drug delivery system for anticancer drugs.

In this paper, nitrogen-doped hierarchical porous carbon (N-HPC) was prepared from polyaniline (PANI)/silica self-aggregates. H-bonding between N H groups in aniline/PANI and OH groups in nano silica template led to a self-assembly type, which enabled the formation of uniform N-HPC nanoparticles. Silica self-aggregates provided macroporous channels resulted in a decreased diffusion distance. After removing the hard template, the N-HPC had a high surface area (899 m2·g−1). Owing to two co-existed synergetic energy-storage mechanisms and the hierarchical porous structure, the obtained N-HPC exhibited a high specific capacitance of 218.75 F·g−1 at 0.5 A·g−1, compared with the nonporous nitrogen-doped carbon (N-C) derived from pure PANI. Moreover, the N-HPC electrode demonstrated excellent cycle life, retaining 99% of its initial specific capacitance after 1000 cycles.

Drug-eluting microspheres based on semi-interpenetrating polymer network (semi-IPN) of modified chitosan (Cs) and poly(2-acrylamide-2-methylpropanesulfonic acid) (PAMPS) were prepared. The preparation included two steps: polymerization of AMPS, formation of Cs/PAMPS microspheres and surface modification of the microspheres. The microspheres were characterized by FTIR analysis and microscope observation. The Cs/PAMPS microspheres showed regular spherical shape with different diameters ranging from 300 to 500 µm. Functional groups of –COOH, –SO3H were introduced into the microspheres, and doxorubicin (DOX) was successfully loaded into microspheres with an enhanced loading rate through ion-exchange interaction of –COOH, –SO3H with amino groups of DOX. Compared with chitosan microspheres, the modified Cs/PAMPS microspheres displayed obvious advantages such as improved drug loading rate, faster loading speed and sustained drug release profile. The drug-eluting microspheres were biocompatible, biodegradable, and could be potentially applied as arterial chemoembolization agent.

The rational design of a sustainable synthetic pathway to develop carbonaceous materials with efficient electrocatalytic activity for energy conversion is a great challenge. Herein, a one-pot method has been applied to synthesize metal–organic framework and polymer nanocomposites (MOF@polymer) with well controlled features, which can be used as a carbon source to produce metal-entrapped, nitrogen-doped mesoporous carbon materials for hydrogen evolution. Specifically, zeolitic imidazolate framework-67 (ZIF-67) was firstly crystallized in 2-methylimidazol aqueous solution, and then green phenolic resin (RF) from phloroglucinol–glyoxylic acid and a catalyst/nitrogen source (triethylenediamine) was co-condensed on the surface of the ZIF-67 crystal in the same system. Then, the obtained ZIF-67@RF nanocomposite transformed into cobalt-entrapped nitrogen-doped mesoporous carbon (Co-NC). Taking the advantages of the cobalt-based electroactive phases, abundant Co–N–C species and the unique porous structure, Co-NCs manifested excellent hydrogen evolution catalytic activity (had an onset overpotential of −45 mV and a small Tafel slope of 65 mV dec−1, in 0.5 M H2SO4 solution) with good stability.

Graphical abstract, Highlights • A layered-MOF (MAMS-1) was efficiently exfoliated to nanosheets in deep eutectic solvent with exfoliation rate more than 70%. • The obtained MAMS-1 nanosheet after encapsulation Eu3+ cations, shows multi-responsive luminescent sensing toward ions. • Eu3+@MAMS-1-NS can specifically recognize Fe3+ , Hg2+ , Cr2 O72− and MnO4−. • The high sensitivity of Eu3+@MAMS-1-NS can attribute to its ultrathin nanosheet morphology and highly accessible active sites on the surface., The exfoliation of bulk two-dimensional metal–organic framework (MOF) into few-layered nanosheets has attracted much attention recently. In this work, an environmental-friendly route has been developed for layered-MOF (MAMS-1) delamination using deep eutectic solvent (DES), which is more sustainable and efficient alternative than conventional organic solvents for MOF nanosheet preparation. Under sonication condition, DES as solvents, the highest exfoliation rate of MAMS-1 is up to 70% with two host layers via poly(vinylpyrrolidone) (PVP) surfactant-assisted method. The presence of tert-butyl exteriors and the atomically thickness endow the MOF nanosheets stable suspension for at least one month. Due to the 2D structure and excellent stability, MAMS-1 nanosheet (MAMS-1-NS) was chosen as a good candidate to encapsulate Eu3+ cations. The obtained Eu3+@MAMS-1-NS acts as a multi-responsive luminescent sensor through fluorescence quenching, and can specifically recognize Fe3+ (LOD = 0.40 μM, KSV = 1.05 × 105 M−l), Hg2+ (LOD = 0.038 μM, KSV = 5.78 × 106 M−l), Cr2O72− (LOD = 0.33 μM, KSV = 1.55 × 105 M−l) and MnO4− (LOD = 0.088 μM, KSV = 4.49 × 105 M−l). Compared with bulk Eu3+@MAMS-1, the sensitivity of Eu3+@MAMS-1-NS is greatly improved owing to its ultrathin nanosheet morphology and highly accessible active sites on the surface.

Stimuli-responsive polymeric micelles were prepared through self-assembly of amphiphilic copolymers poly(ethylene glycol)-poly(γ-benzyl l-glutamate), followed by a core-crosslinking reaction using cystamine as the crosslinking agent. The crosslinked micelles with spherical morphologies in nanometer size showed enhanced stability against dilution and concentrated salt solutions compared to the micelles before crosslinking. Doxorubicin (DOX) as a model drug was encapsulated into the core of micelles through electrostatic interactions between carboxylic acid and DOX. In vitro drug release under pH and redox conditions was investigated. Furthermore, the cytotoxicity of micelles was evaluated before and after drug loading. The endocytosis of DOX-loaded micelles and the intracellular drug release were studied. DOX-loaded micelles exhibited accelerated drug release behaviors in an acidic and reductive environment, and showed an inhibited premature release behavior as compared to the noncrosslinked micelles. Considering their enhanced stability, pH and redox dual triggered responsive characteristics, the polymeric micelles can serve as potential systems for controlled drug delivery.

To avoid the high-temperature process of thermal imprinting, the room-temperature imprint lithography was proposed to pattern thermoplastic polymers. However, the room-temperature imprint lithography is still limited by rigorous condition of high pressure and wasting time. In order to overcome the above-mentioned disadvantages, we have introduced a fast (5 s) imprint method, which is based on the difference of two interfacial forces, to pattern thermoplastic polymers under room-temperature without additional pressure. This method is appropriate for the flat substrate, the curved substrate and the flexible substrate. Furthermore, we also have successfully fabricated 3D hierarchical patterns with antireflection by this method.

Poly[L-lysine-co-N,N-bis(acryloyl) cystamine-co-dodecylamine] nanomicelles (NMs) were synthesized through Michael addition terpolymerization in one pot. The NMs showed spheric morphology and uniform size distributions. The NMs had excellent nonspecific protein adsorption ability at pH 7.4. Doxorubicin (DOX) was loaded in the NMs for the investigation of controlled release. The drug delivery results showed that the DOX-loaded NMs displayed apparent pH and reduction sensitivities in response to the environment of tumor cells due to the existence of carboxyl groups, amino groups, and disulfide bonds in the NMs. The NMs were biocompatible, biodegradable, and could be potentially used as drug vehicles in controlled release.

Taking advantage of cheap raw materials, polyaniline/octa-(aminopropylsilsesquioxane) (PANI/POSS-NH2) composites with hierarchical structures were obtained by a simple and low-cost method of mechanical agitation combined with sonication. The structure, morphology and electrochemical property of PANI/POSS-NH2 were characterized by nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammogram (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). Compared with pure PANI, PANI/POSS-NH2 exhibited good specific capacitance, due to the high specific surface area of POSS-NH2 and synergetic effects of the two components. Moreover, POSS-NH2 played an important role in improving the cycling stability of PANI/POSS-NH2.

Combining TiO2 with conducting polymer could enhance the photoelectric transformation efficiency of absorbed light, due to the formation of P-N heterojunctions. However, few people considered to increase the adsorption efficiency of incident light for the composites. In this manuscript, we demonstrate a facile approach of sequentially assembling TiO2 nanorods and polypyrrole (PPy) on the monocrystalline silicon wafer by the method of hydrothermal synthesis and chemical oxidation. The PPy/TiO2/Si composites with hierarchical structures possessed broadband antireflection and dual P-N heterojunctions, enhancing not only the incident light absorption efficiency but also the utilization efficiency of absorbed light. Thus, PPy/TiO2/Si with hierarchical structures is the excellent candidate materials for the photoelectric device and the photocatalyst.

The traditional single material with two-dimensional (2D) biomimetic moth-eye structures is limited by its narrowband antireflection and single functional capability. To overcome these disadvantages, we exploited wet etching and hydrothermal synthesis coupled with chemical oxidation for fabricating a three-dimensional (3D) biomimetic moth-eye coating with ternary materials (polypyrrole nanoparticles, TiO2 nanorods, and Si micropyramids, i.e., PPy/TiO2/Si-p). This coating reduced the reflectivity to

A novel nano flocculant was prepared through the modification of sodium alginate. In the preparation partially oxidised sodium alginate reacted with triethylenetetramine (TETA) and then reacted with carbon disulfide. The structure of the flocculants was confirmed by elemental analysis, Fourier transform infrared and UV spectrophotometry. The flocculant showed nanoparticle sizes with diameters of 300–350 nm in aqueous solution, and became precipitates after flocculation with Pb2+ ions. The flocculant was employed to adsorb Pb2+ in wastewater, and the influence of flocculant concentration, flocculation temperature, pH, and time on the adsorption properties were investigated. The results showed that adsorption capacity of the flocculant for Pb2+ could reach up to 3.43 mmol g–1, and the removal rate for Pb2+ was over 97%. The adsorption processes corresponded to pseudo second order kinetics and Langmuir isotherm model. The adsorption mechanism involved electrostatic attraction, chemical chelation, netting and sweeping actions.

Cage silsesquioxane with carboxyl groups (POSS-COOH) was successfully synthesized, after which it was added to polypyrrole (PPy) as a dopant to produce the doped PPy (PPy/POSS-COOH) solution. The PPy/POSS-COOH composites were characterized by FTIR (Fourier transformation infrared spectroscopy), SEM (Scanning electron microscopy), TGA (Thermo-gravimetric analysis), CV (Cyclic voltammetry) and RL (Reflection loss). Compared to PPy without POSS-COOH (un-PPy), the conductivity of PPy/POSS-COOH composites could be improved dramatically, reaching up to 0.850 S/cm at 25 °C. Under N2 atmosphere, the residual rate of PPy/POSS-COOH was 68% at 700 °C, 14% higher than the one of un-PPy. Meanwhile, PPy/POSS-COOH had a reflection loss below −8 dB over 9.35 to 11.20GHz, with a minimum value of −10.32 dB at 10.54 GHz, thus demonstrating higher microwave absorption than un-PPy. This method may provide a facile route to produce doped conducting polymers with POSS-COOH.

A new kind of core-crosslinked zwitterionic polymer nano aggregates was prepared by two steps: (1) terpolymers of lipoic acid, polyethylene glycol diglycidyl ether and l -lysine were prepared, forming nano aggregates with hydrodynamic radius of 80 nm–183 nm by self-assembly; (2) the crosslinking of the nano aggregates took place through a reaction of side chain group in lipoic acid structural unit with 1,4-dimercaptothreotol, producing zwitterionic polymer core-crosslinked nano aggregates. The aggregates were stable against dilution and protein adsorption, and they demonstrated good pH/redox dual-responsiveness due to the introduction of disulfide bonds and zwitterionic groups to the nano aggregates. Doxorubicin (DOX) was loaded into the nano aggregates for controlled release. The drug-loaded nano aggregates exhibited obvious pH and reduction sensitivities in response to the environmental conditions in tumor cells. The nano aggregates were biocompatible and could be potentially applied as anticancer drug vehicles for enhancement of cellular uptake of anticancer drugs.

In this paper, we present a convenient and universal strategy to sequentially assemble titania (TiO2) nanorods and polyaniline (PANI) nanoparticles on the Si wafers through hydrothermal synthesis and chemical oxidation. On the one hand, the composite coatings (PANI/TiO2/Si) with hierarchical structures reduced the reflectivity to less than 5 % at the wavelengths from 200 to 2500 nm, namely increasing the absorption efficiency of incident light. On the other hand, the double P–N heterojunctions that the composite coatings developed could suppress the recombination of photogenerated carriers, namely enhancing utilization efficiency of absorbed light. The photocurrent density of PANI/TiO2/Si was above two times higher than that of TiO2/Si at 1.5 V of positive potentials. The application of such coatings in the photocatalysis area, which are fabricated with this method, is thus straightforward.

By employing KOH etching of silicon and hydrothermal growth of titanium oxide (TiO2), TiO2 nanorods assembled on the silicon micropyramids to form biomimetic composite coating, similar to moth-eye structures. The biomimetic composite coating possessed not only the micro–nano hierarchical structures but also the p–n heterojunctions, resulting in a decrease in the reflection of incident light and an increase in the separation efficiency of photogenerated carriers. Meanwhile, the structures showed excellent superhydrophilicity, making for the self-cleaning of the material surface. We further demonstrate that by exploiting the advantages of this method, the application of such structures in the photocatalysis field is thus straightforward.

Zwitterionic copolymers have exhibited high resistance to nonspecific protein adsorption and have wide applications in drug delivery systems. Herein, a pH-responsive poly(Lysine-alt-N,N'-bis(acryloyl) diaminohexane) was synthesized through the Michael addition polymerization between N, N'-bis(acryloyl) diaminohexane and lysine. Subsequently, nano micelles (NMs) were formed by self-assembly of the copolymer in an aqueous solution. The NMs showed a slightly negative charge in blood environment, but a positively charged surface in extracellular pH of tumor. This feature could be used to enhance permeability and retention effect, and reinforce tumor cell uptake. Vitro release studies revealed that the release of DOX from the DOX-loaded NMs was evidently faster at pH 5.0 than at pH 7.4. MTT assays revealed that NMs were nontoxic. Thus, these smart NMs were feasible candidates and could be potentially used in cancer chemotherapy.

An efficient iridium-catalyzed dehydrogenation, ring-closure reaction, has been developed via a cascade sequence, in which [Cp*IrI2]2/Xantphos proved to be the most efficient catalyst for the synthesis of 2,4,6-triaryl-1,3,5-triazines from stable aryl-substituted alcohols and amidines. It was the first case of iridium catalyst successful application in such transformation.

Stimuli-responsive nanoparticles as drug carriers have promising applications in chemotherapy. To increase stability of nanogels in the bloodstream and to enhance intracellular drug uptake, reduction-responsive zwitterionic nanogels were prepared using carboxymethyl chitosan as a material. The preparation included modification of carboxymethyl chitosan and crosslinking by of N,N-Bis(acryloyl) cystamine. The nanogels possessed zwitterions of carboxyl and amino groups, and showed excellent non-fouling behavior against protein adsorption. In the presence of a reduction agent such as glutathione (GSH), the nanogels were dissociated due to scission of disulfide bonds in the crosslinking structure, leading to drug release in tumor cells. The nanogels were non-cytotoxic, biocompatible, biodegradable, and would be potentially used as anticancer drug delivery carriers in controlled release for enhancing cellular drug uptake.

Sodium alginate is a natural biomacromolecule with promising applications as a flocculant for wastewater treatment due to its biodegradability and non-toxicity. To enhance the flocculating efficiency, simplify the synthetic process of the flocculants and expand the application scope of alginate, a novel amphoteric flocculant was synthesized through reaction of alginate with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride under alkaline conditions. The structures of the flocculants were characterized using various methods. The flocculants demonstrated nanoparticle sizes with a narrow distribution. The amphoteric flocculant could not only effectively remove the positively-charged Pb2+ from wastewater, but also removed the negatively-charged humic acid. Under optimum conditions, the removal rates reached 92.32% and 95.18% for Pb2+ and humic acid, respectively. Compared with unmodified alginate, the amphoteric flocculant had significantly improved flocculation for the heavy metal ions and negatively-charged pollutants. The flocculating mechanism for heavy metals was chelating, and was confirmed by X-ray photoelectron spectroscopy, and the flocculating mechanism for humic acid was electric neutralization. The adsorption isotherm could be described by a Langmuir model. The flocculation process accorded with quasi-second-order kinetics equation. This novel amphoteric flocculant has promising applications as an environmentally-friendly treatment agent for wastewater.

Due to the interfacial reflection on the surface of the optoelectronic material and the device, the conversion efficiency to solar energy is limited. Here, a simple method of fabricating bio-inspired TiO2 micro-pyramids with polypyrrole (PPy) nanoparticles on both sides of glass was introduced. This bio-inspired structure, retarding the change of the refractive index from air to sample surface, was fabricated by soft lithography and self-assembly. The two-sided bio-inspired coating presents excellent antireflective performance and photocatalytic activity.

The enhancement of tumor intracellular drug uptake and resistance against nonspecific protein adsorption are essential for an injectable anticancer drug carrier. In the present study, a new type of redox/pH-responsive zwitterionic nanoparticles (NPs) was prepared using poly-L-glutamic acid and cystamine in aqueous solutions under mild conditions. The NPs showed surface charge convertible feature in response to pH change of the solutions. The NPs demonstrated excellent anti nonspecific protein adsorption. In vitro release profiles of the NPs, they showed redox/pH dual sensitivities in vitro release. The effective intracellular delivery behaviors were verified through investigation of cell viability, and confocal laser scanning microscopy observation of HeLa cells after incubation with the DOX-loaded NPs. The NPs were non-cytotoxic and would have potential applications as a drug delivery vehicle for enhancing intracellular uptake of anticancer drugs.

Embolization using microspheres plays an important role in interventional cancer therapy. The drug-eluting embolization microspheres were prepared via reverse suspension crosslinking of gelatin, followed by modification of the cross-linked microspheres. The microspheres displayed regular spherical shapes with size distribution ranging from 180 μm to 350 μm. The negatively charged groups (COO−) were introduced into the microspheres which could load positively charged doxorubicin with loading rates as high as 26.1% and 34.0% in 1 and 12 h, respectively. The high drug-loading rates were ascribed to ionic interaction between carboxyl groups and doxorubicin. The drug release profile showed the modified microspheres (MMS) have a sustained release manner compared with non-MMS in phosphate buffered saline (PBS). The MMS were almost completely degradated after 20 days. Cytotoxicity assay certified that the MMS were non-cytotoxic, and could be potentially used as biocompatible materials.

To enhance drug cellular uptake, a biodegradable terpolymer is synthesized using taurine, N,N-Bis (acryloyl) cystamine, and dodecylamine as raw materials by Michael addition terpolymerization. The terpolymer is transformed to zwitterionic nanoparticles (NPs) through self-assembly. The surface charge of the NPs is convertible from negative at pH 7.4 to positive at pH 6.5, which endows the NPs' excellent nonfouling feature in bloodstream and effective uptake in tumor cells. The NPs display varied morphologies from solid micelles to polymersomes and nanorods depending on molar ratios of the structural units involved. The NPs can be biodegraded in l-glutathione (GSH) solution due to the split of disulfide bonds in main chains of the terpolymers. The NPs demonstrate good pH/reducing responsiveness in drug delivery and can be potentially used as anticancer drug vehicles for enhancement of cellular uptake of anticancer drug.

Hydrophobically modified sodium alginate, poly (lactic-glycolic acid) grafting from sodium alginate (ALG-g-PLGA), was successfully synthesized through direct one-step polymerization of sodium alginate, glycolic acid, and lactic acid. ALG-g-PLGA self-assembled to colloidal nanoparticles and subsequently hydrogel microspheres were obtained by crosslinking ALG-g-PLGA nanoparticles in the solution of calcium chloride. The modified hydrogel microspheres could be used as the drug delivery vehicles for a hydrophobic ibuprofen. Compared with sodium alginate, ALG-g-PLGA demonstrated an improved drug loading rate, encapsulation efficiency, and prolonged release speed. The products, as novel and highly promising biomaterials, have potential applications.

The hydrophobic modification of sodium alginate was realized by direct grafting with glycolic acid. The products, polyglycolic acid grafting from sodium alginate (Alg-g-PGA), self-assembled into nanoparticles of 200–250 nm in diameter through the interaction of hydrophobic PGA segments in the aqueous solution. Alg-g-PGA nanoparticles were cross-linked into hydrogel microspheres by calcium chloride, which was used as drug delivery vehicles for controlled release. The results of drug (ibuprofen) release model exhibited high drug loading rate and prolonged drug release speed of the Alg-g-PGA gel microspheres. The one-step method of synthesizing hydrophobically modified sodium alginate processes simple operation, mild condition, and low-cost raw material, resulting in its wide application of biological medicine in the future.

Copolymers of poly(n-butyl methacrylate-co-glycidyl methacrylate) were prepared by a free radical polymerization. The structures of the copolymers were characterized. The copolymers could be added to a powder epoxy resin (E663) to form modified epoxy resins. It was found that toughness of the cured modified epoxy resins were greatly improved, impact strength increased 3 times and fracture elongation increased 20% compared to the cured unmodified E663 resin. This is because that the copolymers had epoxy groups and flexible butyl groups, the former were involved in cross-linking reaction of the E663, and the latter made contribution to the toughness improvement.

Graft copolymers of poly(vinyl alcohol-g-lactic acid) (PVA-g-PLA) were synthesized through a direct polycondensation of d,l-lactic acid grafting from polyvinyl alcohol (PVA) using 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCl) as the catalyst. The molecular weights of the graft copolymers varied from 98,000 to 106,000, which were determined by gel permeation chromatography. It was observed that the glass transition temperatures of the copolymers decreased with the increase of lactic acid units in the copolymers. Thin films with the thickness of 0.04–0.06 mm were prepared using the copolymers. The films showed improved hydrophilicity and flexibility compared with PLA homopolymer. Small pieces of the films were implanted under the skin of mice for anti-tissue adhesion purpose. The films demonstrated good anti-tissue adhesion behavior and suitable degradability in the mouse body. The graft copolymers were non-toxic, flexible, blood compatible, non-cytotoxic and had potential applications as a medical anti-tissue adhesion agent.

A polyion complex nano-prodrug based on the complexation of the ionomer of poly(lactic acid-co-malic acid)-block-polyethylene glycol [Poly(LA-co-MA)-b-PEG] with doxorubicin (DOX) was developed. The ionomer was prepared by a direct polycondensation of d,l-lactic acid (LA), l-malic acid (MA), and monomethyl polyethylene glycol (PEG) using stannous chloride (SnCl2) as the catalyst. The nanoparticles were formed through electrostatic interactions between the side carboxyl groups of MA units in the ionomer and amino groups of DOX. The nanoparticle possessed an amphiphilic structure with a hydrophobic core of the complexed DOX and Poly(LA-co-MA) and a hydrophilic shell of PEG. The nanoparticle solution was stable, and the particle sizes were in the range of 110–140 nm. The DOX was loaded as a prodrug with loading rate as high as 18.2 %. The drug release could be controlled, showing responsiveness of acids and ionic strength. The cumulative release was as high as 94 %. The nanoparticles could be potentially used as anti-cancer drug vehicles.

The epoxy-functionalized copolymers were prepared by copolymerization of n-butyl acrylate (nBA) and glycidyl methacrylate (GMA) in a solution. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel-permeation chromatography. The copolymers were added to epoxy resin E44 for modifying the properties of the cured epoxy resin. The results showed that some properties of the cured epoxy resin were apparently improved through the addition of the copolymers. The kinetic studies indicate that the curing process was continuous with average activation energy of 51.13 kJ/mol, which was calculated based on Kissinger and Ozawa models.

Terpolymers of poly (Lysine-co-N, N-Bis (acryloyl) cystamine-co-β-Phenethylamine) (PLBP) were synthesized in one-pot by Michael addition terpolymerization. The terpolymers self-assembled into nano-sized spherical micelles (84-123nm) with narrow distributions. The surface charge of the nanomicelles (NMs) was depended on solution's pH and showed negative values under physiological conditions (pH7.4), which was beneficial for long circulation without non-specific protein adsorption. Doxorubicin (DOX) was effectively loaded into the NMs for controlled release. The in vitro release profiles exhibited obvious pH and reduction sensitivities in response to the environment mimicking tumor cells. The MTT assays demonstrated that blank NMs were biocompatible, and drug-laden NMs showed a significant cytotoxicity on Hela cells. The NMs could be potentially applied as smart drug delivery systems in cancer therapy.

The one-pot synthesis method was developed for the preparation of complex nanoparticles with a narrow size distribution and stable morphology. The vinyl monomers of (2-dimethylamino)ethyl methacrylate (DEMA) and diacetone acrylamide (DAA) were copolymerized in the presence of alginic acid in an aqueous solution without any organic solvents or surfactants, yielding stable complex nanoparticles in one-pot synthesis. The nanoparticle was composed of the complex of poly(DEMA-co-DAA) and alginic acid. The complex was formed via electrostatic interaction between polycations of DEMA and polyanions of alginate. The residual alginate segment around the core formed the shell of the nanoparticles. The average diameter of the nanoparticles varied from 120 to 213 nm when the molar percentage of DAA changed from 0.5 to 0 with respect to DEMA. The anti-cancer drug doxorubicin could be loaded onto the nanoparticles with a high-loading efficiency through the formation of polymer–drug conjugate. The drug release could be controlled by adjusting the pH value of the medium.

Covalently crosslinked and hydrophobically modified alginate hydrogels were prepared through esterification of alginic acid (ALG-H) with 1,10-decanediol that functioned as a crosslinking agent and hydrophobic component. The preparation was accomplished with one step and was carried out in N,N-dimethylformamide solution at a reduced pressure for removing the water produced. The characterization results confirmed the esterification of the products. The modified alginate hydrogels could be used as drug delivery vehicles for controlled release. The drug release study revealed that compared with a calcium alginate hydrogel the modified hydrogels possessed improved loading rate and encapsulation efficiency for the hydrophobic drug(ibuprofen), and a remarkable sustained release behavior was observed. The release kinetics was close to zero order, a desirable drug release pattern. The modified alginate hydrogels were nontoxic and were potentially applicable as a promising biomaterial. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Magnetic star-shaped amphiphilic copolymers (S-Fe3O4-PLA-b-MPEG) consisting of Fe3O4 as the core, poly(L,D-lactide) (PLA) as the inner layer, and monomethyl polyethylene glycol (MPEG) as the out shell were synthesized. The syntheses included ring-opening polymerization of L,D-lactide initiated by hydroxyl modified Fe3O4 (Fe3O4-(OH) n), followed by the esterification of the PLA with MPEG. The structure of the star block copolymers were characterized by Fourier Transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, nanoparticle size analyzer, and vibrating sample magnetometer. The nanoparticles in aqueous solution were made from the amphiphilic star copolymer. The average size of the nanoparticles was adjustable and increased with the increase of the PLA segments in the copolymer. The cytotoxicity grade of the nanoparticles was zero determined by the analysis of cytotoxicity. The nanoparticles could potentially be used as the drug vehicles for magnetic-response controlled release. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Poly(N-isopropylacrylamide) was grafted on the surface of ultrafine silica beads through coupling reaction of semi-telechelic poly(N-isopropylacrylamide) (PNIPAm) and the silica beads. The synthetic route included the preparation of semi-telechelic PNIPAm with triethoxysilan group at the polymer chain end and the coupling reaction of the semi-telechelic PNIPAm with silica particles. The characterizations by infrared spectrometry, differential scanning calorimetry, scanning electron microscopy, and thermogravimetry analysis confirmed the formation of core-shell composites of silica-PNIPAm. The composites were thermo-sensitive and were used as a packing material in high-performance liquid chromatography (HPLC) for separating organic compound mixtures. The result indicated that satisfactory separations could be achieved by controlling the column temperature.

Monodispersed complex nano-particles were synthesized simply by mixing alginic acid (ALG-H) with poly[(2-dimethylamino) ethyl methacrylate] (PDEMA) in pure water without any surfactants or additives. The structure and properties of the nano-particles were extensively studied. The surface charges and average sizes of the nano-particles were varied with the composition of ALG-H and PDEMA. The nano-particles were formed through electrostatic attraction force, and they were very stable in pure water, but dissociated in salt solutions. An anticancer drug (doxorubicin) was loaded in the nano-particles and released in different saline solutions. The release profiles revealed that the drug release could be controlled by adjusting the pH and salt concentrations. The nano-particles displayed apparent advantages such as simple preparation process, low cost, free of organic solvents, size controllable, biodegradable and biocompatible.

Firstly, nano-sized polyhedral oligomeric silsesquioxane with functional mercapto groups (POSS-SH) was prepared through hydrolytic condensation of 3-mercaptopropyl trimethoxysilane. Then N-isopropylacrylamide (NIPAm) was allowed to polymerize at the presence of POSS-SH and N,N-methylene-bisacrylamide to yield hybridized hydrogels. The hybridized hydrogels demonstrated thermosensitive behavior across the volume phase transition temperatures. The swelling and deswelling rates were greatly accelerated through the incorporating of POSS-SH into the gels, and the thermal properties of the hybridized hydrogels were reinforced compared with the neat PNIPAm hydrogel. These results were ascribed to nano-effect created by the hydrophobic POSS-SH nanoparticles. The hybridized hydrogels have potential applications in drug controlled release.

Amphiphilic block copolymer of sodium polystyrene sulfonate (PSS) and polystyrene(St) was prepared under ultrasonic irradiation. The PSS fragment radicals created during the degradation process was used to initiate the polymerization of styrene(St), and a diblock copolymer of poly(SS-b-St) was obtained when the degradation of PSS and the polymerization of St occurred simultaneously. The block copolymers underwent self assembly in aqueous solution, and formed stable nano micelles with diameters of 95–128 nm. The influence of ultrasonic irradiation on the formation of the block copolymers and micelles were investigated.

A series of N-(2-substituted-5,6,7-trihydroquinolin-8-ylidene)-arylaminonickel(II) dichlorides were synthesized by the one-pot stoichiometric reaction of nickel dichloride, 2-chloro- or 2-phenyl-substituted 5,6,7-trihydroquinolin-8-one, and the corresponding anilines. All nickel complexes were characterized by elemental and spectroscopic analysis. The molecular structures of representative nickel complexes, determined by the single-crystal X-ray diffraction, indicate the different coordination numbers around nickel either four with more bulky ligands or five with less bulky ligands. All nickel complexes, activated with ethylaluminium sesquichloride (Et3Al2Cl3), showed high activities (up to 9.5 × 106 g mol−1 h−1) in ethylene oligomerization for dimer and trimers.

Inorganic/polymer hybrid star-shaped block copolymer nano-micelles were synthesized. In the synthetic route, multi-hydroxyl polyhedral oligomeric silsequioxane(POSS-(OH)32) was employed as the starting molecule to initiate ring-opening polymerization of d,l-lactide. 2-(Dimethylamino)ethyl methacrylate was found to polymerize at the end of polylactic acid chains, following mechanism of atom transfer radical polymerization. The well-defined star block copolymer core–shell nano-micelles were finally obtained. The structures of the copolymer and the micelles were characterized extensively. The micelles exhibited a regular spherical shape with an average diameter of 170 nm which was confirmed by transmission electron microscopy and dynamic laser scattering. The sizes of both the core and the shell were controlled by adjusting the feed ratios during the syntheses. The micelles demonstrated pH- and temperature-sensitive behaviors.