Multifunctional Hybrid Materials Research Articles

Porphyrin decorated Bi2O2CO3 nanocomposites with efficient difunctional properties of photocatalysis and optical nonlinearity

Considerable attention has been paid to design multifunctional hybrid materials for developing novel optoelectronic systems. Here, a series of novel porphyrin decorated Bi2O2CO3 nanocomposites (BOC/TPP) loaded with different porphyrin contents was prepared by a facile solvothermal technique to maximize the photocatalysis and optical nonlinearity. The photoresponsive range of the BOC/TPP nanocomposites can be extended from UV to visible light, and the band gap can be continuously tuned. The wide absorption of the as-prepared nanocomposites in the visible light region makes them suitable for photocatalytic and nonlinear transmission studies. The associated photocatalysis and optical nonlinearity for the BOC/TPP nanocomposites are shown to be dependent on the contents of porphyrin. Compared to BOC, TPP and other prepared nanocomposites with different TPP loadings, the BOC/0.03TPP nanocomposite with 3 wt% TPP exhibits the highest photocatalytic performance and nonlinear optical absorption effect, due to the efficient interfacial charge transfer and the strong interfacial electronic interactions between TPP and BOC. These findings provide an ideal scientific platform to guide the rational design of difunctional nanomaterials with desired optoelectronic performances.

Molecular chemistry approaches for tuning the properties of two-dimensional transition metal dichalcogenides.

Two-dimensional (2D) semiconductors, such as ultrathin layers of transition metal dichalcogenides (TMDs), offer a unique combination of electronic, optical and mechanical properties, and hold potential to enable a host of new device applications spanning from flexible/wearable (opto)electronics to energy-harvesting and sensing technologies. A critical requirement for developing practical and reliable electronic devices based on semiconducting TMDs consists in achieving a full control over their charge-carrier polarity and doping. Inconveniently, such a challenging task cannot be accomplished by means of well-established doping techniques (e.g. ion implantation and diffusion), which unavoidably damage the 2D crystals resulting in degraded device performances. Nowadays, a number of alternatives are being investigated, including various (supra)molecular chemistry approaches relying on the combination of 2D semiconductors with electroactive donor/acceptor molecules. As yet, a large variety of molecular systems have been utilized for functionalizing 2D TMDs via both covalent and non-covalent interactions. Such research endeavours enabled not only the tuning of the charge-carrier doping but also the engineering of the optical, electronic, magnetic, thermal and sensing properties of semiconducting TMDs for specific device applications. Here, we will review the most enlightening recent advancements in experimental (supra)molecular chemistry methods for tailoring the properties of atomically-thin TMDs - in the form of substrate-supported or solution-dispersed nanosheets - and we will discuss the opportunities and the challenges towards the realization of novel hybrid materials and devices based on 2D semiconductors and molecular systems.

A supramolecular hybrid material constructed from pillar[6]arene-based host-guest complexation and ZIF-8 for targeted drug delivery.

A novel supramolecular hybrid material ZIF-8@DOX@WP6@G constructed from the host-guest complexation between carboxylated pillar[6]arene (WP6) and a galactose derivative (G), and doxorubicin (DOX)-loaded ZIF-8 has been synthesized for targeted drug delivery. The results showed that ZIF-8@DOX@WP6@G not only maintained the pH-sensitive drug release properties of ZIF-8 but also exhibited excellent water dispersibility and selective toxicity for hepatoma cancer cells due to the assembly of WP6 and G. The strategy used in this study opens up a new avenue for constructing multifunctional supramolecular hybrid materials for therapeutic applications in cancer treatment.

"Click" chemistry as a tool to create novel biomaterials: a short review

In recent years, there has been a growing demand for novel strategies for biomedical applications. Chitosan is a typical cationic amino-containing polysaccharide that has been widely used due to its unique properties. The grafting modification of chitosan has been explored as an interesting method to develop multifunctional novel chitosan hybrid materials for drug delivery, tissue engineering, and other biomedical applications. Recently, “click” chemistry has been introduced into the synthesis of polymeric materials with well-defined and complex chain architectures. The Huisgen’s 1,3-dipolar cycloaddition reaction between alkynes and azides yielding triazoles is the principal example of a “click” reaction. Bioconjugation, surface modification, and orthogonal functionalization of polymers were successfully performed through this chemoselective reaction. In recent literature interest has been shown in this cycloaddition for the modification of polysaccharides, however, only a few chitosan graft copolymers have been synthesized by this technique.

Tailored Ce- and Zr-doped Ni/hydrotalcite materials for superior sorption-enhanced steam methane reforming

Multi-functional hybrid materials are attractive for producing high-purity hydrogen (H2) via catalytic steam reforming coupled with low temperature adsorptive separation of CO2. In this work, modified Ni/hydrotalcite-like (HTlc) hybrid materials promoted with Ce and Zr species were synthesized and applied for the sorption-enhanced steam methane reforming process (or SESMR). The promotion with Ce and Zr resulted in strongly basic sites for CO2 adsorption, and hence, improved H2 production. Especially, the Ce-promoted hybrid material (Ce-HM1) exhibited the highest adsorption capacity (1.41 mol CO2/kg sorbent), producing 97.1 mol% H2 at T = 723 K, P = 0.1 MPa, S/C = 4.5 mol/mol and gas hourly space velocity or GHSV = 3600 mL/(g h); the breakthrough time was 1 h. High surface area and basicity of the promoted materials inhibited coke formation and undesired reactions. In addition to the improved catalytic activity and adsorption characteristics, these materials were stable and easily regenerable. Multi-cycle durability tests revealed that both the promoted materials Ce-HM1 and Zr-HM1 remained stable for up to 13 and 17 cycles. In contrast, the unpromoted hybrid material (HM1) was stable for 9 cycles only. Thus, promotion with Ce and Zr was beneficial for producing pure H2.

Development of lignin based multifunctional hybrid materials for Cu(II) and Cd(II) removal from the aqueous system

In the paper the synthesis and comprehensive physicochemical characterization of a new group of adsorbents containing inorganic oxides and functional biopolymers from the lignocellulose group o such as TiO2/lignin, TiO2-SiO2/lignin and MgO-SiO2/lignin are presented. The obtained materials were evaluated taking into account their physicochemical properties and utility as sorbents towards Cu(II) and Cd(II) ions. Among others, surface activity, porous structure, particle size distribution, SEM images, adsorptive properties (BET isotherms) and electrokinetic properties (zeta potential and electrophoretic mobility) as well as effectiveness of the surface functionalization by the FT-IR method were determined. In addition, the optimum conditions for the adsorption process, its theoretical description and determination of interactions at the adsorbent-adsorbate interface were also included. The kinetic, adsorption and thermodynamic parameters were calculated using the common models. The adsorption and the kinetic data were well described using the Langmuir and pseudo-second order models. The results showed the affinity is greater in the case of Cd(II) and next Cu(II). The metal ion adsorption is a heterogeneous, endothermic and spontaneous reaction on the hybrid material surface.

Computer simulations of the structure and properties of organic pillared MFI zeolite catalyst

Multifunctional porous hybrid materials have recently received a lot of attentions because they combine the advantages of incorporating both inorganic oxides and organic species into the structure to solve the limitation of sole component material. This paper reports a type of model of organic pillared MFI zeolite catalyst, in which the full-atom mimetic model is constructed by using molecular modeling technique. Dreiding force field is used to calculate the interactions between sorbate–sorbate and sorbate–sorbent in the organic pillared MFI zeolite. The optimized model is characterized by calculating low-angle and high-angle X-ray diffraction patterns. Besides, the adsorption behavior of benzene and toluene is also investigated through the mimetic model. Simulated adsorption isotherms of benzene and toluene are agreement with the experimental data at low pressure. Density distributions of benzene and toluene show that toluene adsorbs preferentially in the region of interlayer space of lamellar MFI zeolite while benzene tends to adsorb in the area of micropores at low pressure. With increasing pressure, the guest molecules gradually fill in the area of micropores and mesopores of the organic pillared MFI zeolite. Moreover, the developed strategy in the present work can be applied to build other model for organic pillared zeolite catalyst by arranging different zeolite frameworks or organic species.

Preparation and characterization of ZnO/ZIF-8 composite with selective photoelectrochemical responses

The combination of ZIFs with semiconductor materials is expected to get multi-functional hybrid materials with synergistic effects of the individual components. ZnO/ZIF-8 composites with blocklike structure were synthesized via a hydrothermal method. The dark and illuminated current density of the ZnO/ZIF-8 photoelectrodes is greatly decreased compared with pure ZnO. Opposite changes of photocurrent response are observed with addition of hole scavengers with different sizes, which verifies the molecular size selectivity of photoelectrochemical (PEC) response of ZnO/ZIF-8 composite. This novel composite may be potentially developed into a new-type of PEC sensors with molecular size selectivity.

Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization.

Understanding the mechanisms responsible for generating different phases and morphologies of calcium phosphate by elastin-like recombinamers is supreme for bioengineering of advanced multifunctional materials. The generation of such multifunctional hybrid materials depends on the properties of their counterparts and the way in which they are assembled. The success of this assembly depends on the different approaches used, such as recombinant DNA technology and click chemistry. In the present work, an elastin-like recombinamer bearing lysine amino acids distributed along the recombinamer chain has been cross-linked via Huisgen [2 + 3] cycloaddition. The recombinamer contains the SNA15 peptide domains inspired by salivary statherin, a peptide epitope known to specifically bind to and nucleate calcium phosphate. The benefit of using click chemistry is that the hybrid elastin-like-statherin recombinamers cross-link without losing their fibrillar structure. Mineralization of the resulting hybrid elastin-like-statherin recombinamer hydrogels with calcium phosphate is described. Thus, two different hydroxyapatite morphologies (cauliflower- and plate-like) have been formed. Overall, this study shows that crosslinking elastin-like recombinamers leads to interesting matrix materials for the generation of calcium phosphate composites with potential applications as biomaterials.

Synthesis of graphene-coated carbon nanotubes-supported metal nanoparticles as multifunctional hybrid materials

This paper presents a methodology to produce hybrid multifunctional materials based on graphene coated-metal nanoparticles supported on carbon nanotubes (M-CNT). These hybrid materials were synthetized by impregnation-reduction-decoration (IRD) methodology. Supported metal nitrates, were decomposed and reduced in-situ with CNT. After the reducing procedure, metal particles were treated with methane pulses at temperatures between 700 °C and 900 °C to encapsulate them into a few graphene sheets. These hybrid materials were characterized through different analytical techniques. In-situ X-ray diffraction analysis showed that the decomposition of nitrates occurs simultaneously with an in-situ reduction of metal particles by utilizing CNT as reducing agent. The nucleation of these metal particles preferentially starts over carbon nanotubes defects. Synthetized metal nanoparticles are active for methane decomposition, allowing the deposition of carbonaceous materials and their crystallization as graphene layers covering the metal particles (between one and four graphene layers). Magnetic characterization suggests that these hybrid materials can be used for development of magnetic storage devices, while their multifunctional properties could be potentially exploited for development of a variety of catalysts and sensors.

Luminescent metal-organic frameworks for nitro explosives detection

Metal-organic frameworks (MOFs) have been emerging as important multifunctional hybrid materials, not only due to the diversify framework architectures, but also contribute to the rich interactions among metals, ligands and guests. Nitro explosives have important influences for environmental protection and national homeland security. In this review, a brief description of luminescent MOFs is presented, accompanied by a short comment on the four types of metal-based luminescent MOFs as sensing materials for nitro explosives detection. Then the trends and challenges of luminescent MOFs as sensing materials for nitro explosives are also prospected.

Carboxymethyl cellulose based hybrid material for sustained release of protein drugs

Hybrid materials contain polysaccharide based network and biomimetic calcium phosphate are potentially appropriate for bone repair and drug release. Novel hydrogel composed of carboxymethyl cellulose backbone grafted with crosslinked poly(dimethylaminoethyl methacrylate) CMC-g-PDMAEMA was subjected to biomimetic calcium phosphate mineralization through simulated body fluid. Infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) confirmed calcium phosphate mineralization while X-ray diffraction and transmission electron microscopy (TEM) results suggested that the deposited phase contains mineralized component of bone, hydroxyapatite. CMC-g-PDMAEMA hydrogels before and after calcium phosphate mineralization were investigated as a drug carrier and the results showed significant efficiency of the mineralized hydrogel to deliver bovine serum albumin (BSA). These results indicated that CMC-g-PDMAEMA/calcium phosphate could serve as a new class of multifunctional hybrid materials for various biomedical applications.

Hierarchical nanoporous silica doped with tin as novel multifunctional hybrid material to flexible poly(vinyl chloride) with greatly improved flame retardancy and mechanical properties

Antimony trioxide (Sb2O3) is a traditional widely used flame retardant in flexible poly(vinyl chloride) (fPVC). However, more and more serious drawbacks of this flame retardant, such as the underlying toxicity and decreasing reserve in the earth’s crust, obligate the development of its substitutes. To address this issue, we synthesized novel mesoporous flame retardant (TOS) by grafting of tin on hierarchical nanoporous silica (HPS) via a facile in-situ synthesis method. Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission gun scanning electron microscope (FEGSEM), transmission electron microscopy (TEM) and N2 adsorption–desorption measurement were utilized to investigate the composition and structure of the mesoporous material. TOS, HPS, commercial tin oxide (SnO2) and Sb2O3 were added into fPVC composites respectively to carry out comparative study. Results showed limiting oxygen index (LOI) of fPVC composite was significantly increased in presence of TOS, accompanied with UL-94 V-0 rating without dripping. Meanwhile, TOS also enhanced the tensile properties of fPVC composite significantly. All the data illuminated that TOS greatly improved flame retardancy and mechanical property of fPVC as a novel multifunctional hybrid materials.

Magnetic double-tartaric bridging mono-lanthanide substituted phosphotungstates with photochromic and switchable luminescence properties

A series of inorganic–organic hybrid multifunctional crystalline materials constructed using double-tartaric bridging mono-lanthanide substituted phosphotungstates display reversible photochromic, switchable luminescence, and magnetic properties.

Magnetic hyperthermia-induced drug release from ureasil-PEO-γ-Fe2O3 nanocomposites

A multifunctional hybrid material suitable for cancer therapy, combining stimuli-responsive properties for drug delivery and magnetic hyperthermia.

Functionalization of organically modified silica with gold nanoparticles in the presence of lignosulfonate

It is shown that lignosulfonate (LS) can be used as an effective reducing agent for gold ions and simultaneously as a stabilizing agent for gold nanoparticles (AuNPs). When organically modified silica is introduced to the reaction mixture, most of the AuNPs grow on the surface of the silica due to hydrophobic interactions between LS and organic layers covering the solid particles. It was also found that the structure of the organic layer is crucial for the effective deposition of gold nanoparticles onto silica spheres in terms of particle size and gold content in the final SiO2-LS-AuNPs composites. Due to the hydrophobicity of the modified silica it was necessary to carry out the modification in mixed organic/aqueous solvent. The polarity of the organic co-solvent was found to have an effect on the size of the deposited Au-NPs and their quantity. The physical appearance of the obtained hybrids was analyzed by colorimetry, and their structure and composition were evaluated using transmission electron microscopy (TEM). Additionally dispersive and thermal properties were examined by dynamic light scattering (DLS) and thermogravimetry (TG), respectively. The obtained multifunctional hybrid materials exhibits remarkable catalytic activity for the reduction of C.I. Basic Blue 9 (Methylene Blue) by borohydride.

"Click" chemistry as a tool to create novel biomaterials: a short review

In recent years, there has been a growing demand for novel strategies for biomedical applications. Chitosan is a typical cationic amino-containing polysaccharide that has been widely used due to its unique properties. The grafting modification of chitosan has been explored as an interesting method to develop multifunctional novel chitosan hybrid materials for drug delivery, tissue engineering, and other biomedical applications. Recently, “click” chemistry has been introduced into the synthesis of polymeric materials with well-defined and complex chain architectures. The Huisgen’s 1,3-dipolar cycloaddition reaction between alkynes and azides yielding triazoles is the principal example of a “click” reaction. Bioconjugation, surface modification, and orthogonal functionalization of polymers were successfully performed through this chemoselective reaction. In recent literature interest has been shown in this cycloaddition for the modification of polysaccharides, however, only a few chitosan graft copolymers have been synthesized by this technique.

Processing of a new class of multifunctional hybrid for electromagnetic absorption based on a foam filled honeycomb

A multifunctional hybrid material class in the form of a sandwich panel has been developed towards the combined optimization of mechanical and electromagnetic absorption performance. The faces of the panel are made of glass fibre reinforced epoxy composites and the core is made of carbon nanotube reinforced polymer foam filling a metallic honeycomb. The different processing strategies and options tested to fabricate the core material are described as well as the associated scientific and technological issues. The most efficient processing route is by foaming the nanocomposite with a chemical foaming agent directly inside the honeycomb. This route offers a good surface finish and the operation can be achieved in one step. But, in order to produce large panels with a semi-continuous process, thermo-mechanical insertion of the foamed nanocomposite with supercritical CO2 can be more suitable. The characterization of the electromagnetic absorption of the panels produced by different routes shows that the performance is not much sensitive to processing defects making possible upscaling to mass production.

Preparation of metal-ion containing polymers: Synthesis and characterization of methacryliccopolymers containing copper ion

Organic-inorganic hybrid materials have attained great attention due to their complementary properties from each material. Although there have been numerous reports considering the hybrid materials, it is still challenging task to develop easy accessible and versatile method for fabrication of multifunctional organic-inorganic hybrid materials. Herein, we propose novel concept to prepare metal-ion containing polymeric materials. Copper containing copolymers were prepared via radical polymerization of the copper containing monomers with several different monomers. The copper nanoparticles obtained from the direct chemical reduction show the different oxidation and hydroxidation behaviors depending on the degree of interactions for the functional groups in copper containing polymers with oxygen and/or water. Finally, because these copper containing copolymers were shown to be soluble in various organic solvents, we have attempted to produce nanofibers using electrospinning in order to confirm the excellent processability of prepared copper containing polymer.

Multifunctional uranyl hybrid materials: structural diversities as a function of pH, luminescence with potential nitrobenzene sensing, and photoelectric behavior as p-type semiconductors.

A series of uranyl-organic frameworks (UOFs), {[(UO2)2(H2TTHA)(H2O)]·4,4'-bipy·2H2O}n (1), {[(UO2)3(TTHA)(H2O)3]}n (2), and {[(UO2)5(TTHA) (HTTHA)(H2O)3]·H3O}n (3), have been obtained by the hydrothermal reaction of uranyl acetate with a flexible hexapodal ligand (1,3,5-triazine-2,4,6-triamine hexaacetic acid, H6TTHA). These compounds exhibited three distinct 3D self-assembly architectures as a function of pH by single-crystal structural analysis, although the used ligand was the same in each reaction. Surprisingly, all of the coordination modes of the H6TTHA ligand in this work are first discovered. Furthermore, the photoluminescent results showed that these compounds displayed high-sensitivity luminescent sensing functions for nitrobenzene. Additionally, the surface photovoltage spectroscopy and electric-field-induced surface photovoltage spectroscopy showed that compounds 1-3 could behave as p-type semiconductors.