3DOM Materials Research Articles

Investigation of 3-D ordered materials with a high adsorption capacity for BSA and their potential application as an oral vaccine adjuvant

3-D ordered macroporous (3DOM) materials were customized for BSA adsorption and further oral immunization. These carriers have a high adsorption capacity and our customized carrier showed a distinctive double-plateau adsorption behavior. Different BSA release rates (between the two plateaus) could be obtained by adjusting the ratio of the protein adsorbed on the internal surface and the external surface. This suggests that the release pattern was determined by the adsorption state. One benefit is that the same carrier could have different release profiles making it possible to study the relationship between the release behavior and adjuvant effects without any distractions. Compared with free BSA alone, a significantly higher level of serum IgG, IgA induced by BSA/3DOM was observed and the release profile had an effect on the immunity. The IgG1 and IgG2a titers suggesting that both the Th1 and Th2 mediated immune response were induced. Therefore, this research could help in the development of a novel inorganic oral adjuvant and provide a new avenue for the administration of oral vaccine.

A polymer based and template-directed approach towards functional multidimensional micro-structured organic/inorganic hybrid materials

The control over structure and function in hierarchically multidimensional materials based on hollow spheres, nanowires, nanorods, nanotubes, fibres, membranes or inverse opals with adjustable dimensions has gained considerable attention due to their tremendous potential for a wide variety of applications. Herein we describe convenient and efficient synthetic concepts for synthesis and processing of well-defined polymer-templated inorganic materials with 0D, 1D, 2D and 3D nano- and microstructures. In the first step, we describe universal methodologies for the controlled build-up of polymer-templated non-functional inorganic structures by taking advantage of lower dimensional structures such as core–shell particles or fibres. With this approach it is possible to obtain more sophisticated architectures such as 3D ordered macroporous (3DOM) materials after applying different procedures for organization, e.g. the powerful melt shear technique as well as novel double-templating strategies towards multidimensional carbon architectures. To prove the feasibility of our protocols established herein we have exemplarily applied these methods to the formation of functional inorganic high-temperature materials, such as silicon carbide (β-SiC) and yttria-stabilized zirconia (YSZ). The general pathways for the controlled build-up of nano- and micro-scaled structures based on polymer templates may thus provide a facile and versatile route to an even wider variety of organic/inorganic composite materials offering a wider range of future applications in the fields of catalysis, separation, sensors, optics, and biomedicine. Herein we show first examples of selected new material morphologies towards energy related issues, namely Li-ion battery applications and heterogeneous catalysis (selective ethanol oxidation).

Upconversion luminescence properties of three-dimensional ordered macroporous CeO2: Er3+, Yb3+

• Three-dimensional ordered macroporous CeO 2 : Er 3+ , Yb 3+ was prepared. • UC emission in the 3DOM sample was obtained. • Relative intensity of the red to green emission increased in the 3DOM sample. Three-dimensional ordered macroporous (3DOM) Er 3+ , Yb 3+ co-doped CeO 2 and powder samples were prepared. The phase of the 3DOM sample was confirmed by XRD, and upconversion (UC) luminescence property was investigated. The results showed that green (527 nm, 548 nm) and red (659 nm) emission bands were observed in the 3DOM and powder samples under a 980 nm excitation at room temperature. It is interesting that the relative intensity of the red to green emission in the 3DOM sample increased in comparison with that of powder sample due to the increased non-radiative relaxation from 4 I 11/2 to 4 I 13/2 state in the 3DOM materials.

Contrastive study of structure and photocatalytic performance with three-dimensionally ordered macroporous CuO–TiO2 and CuO/TiO2

To study the effects of combination way of CuO and TiO2 on their structure and catalytic properties, two three-dimensionally ordered macroporous (3DOM) materials CuO–TiO2 and CuO/TiO2 were prepared. The morphology, composition and structure of the prepared catalysts were characterized by XRD, SEM, HRTEM, N2 adsorption, XPS, and UV-VIS DRS. SEM and N2 adsorption analysis indicate that the effect of the existence form of CuO on morphology and pore structure is very tiny. XRD, HRTEM, XPS characterizations show that the existence forms of CuO for the two samples (CuO–TiO2 and CuO/TiO2) are mainly constitutive of skeleton CuO and surface CuO, respectively. UV-VIS DRS indicates that the CuO–TiO2 sample show broader visible light response region and narrower band gap than those of the CuO/TiO2 sample. These findings reveal that the appearance of skeleton CuO promote the efficiencies of light harvest and charge carrier separation, ultimately enhancing the photodecoloration performance of MB.

Effects of Integrated Carbon as a Light Absorber on the Coloration of Photonic Crystal-Based Pigments

Three-dimensionally ordered macroporous (3DOM) materials prepared by colloidal crystal templating are examples of photonic crystals that can exhibit structural color. The color intensity can vary widely, from a pale, nearly white opalescence to vivid, brilliantly metallic colors. Such variations are observed even for 3DOM materials of a single nominal composition that exhibit virtually identical structural order in scanning electron micrographs and are prepared from the same colloidal crystal templates. In this study we investigate the cause of the variations in color intensity for 3DOM ZrO2 systems, considering both the role of zirconia grains in the skeleton of the photonic crystal and the presence or absence of carbonaceous components in the material. Such components act as broad spectral light absorbers and are introduced either directly in the synthesis through the precursor and the polymeric template or by postsynthesis addition and carbonization of sucrose solutions. We conclude that grain-size eff...

ChemInform Abstract: Design and Functionality of Colloidal‐Crystal‐Templated Materials—Chemical Applications of Inverse Opals

AbstractReview: 289 refs.

Enhanced adsorption capacity and selectivity towards salicylic acid in water by a cationic polymer functionalized 3-D ordered macroporous adsorbent

3-D ordered macroporous (3DOM) materials have exhibited advantages in the adsorption field. Their monodisperse macropores undergo facile modification, and the interconnected cavities enhance accessibility to the active sites, while the short diffusion path of the thin pore walls accelerates material exchange. A 3DOM material can increase the number of adsorption sites by the grafting of a polymer chain with functional groups from the pore wall of the 3DOM resin. In this study, different amounts of the cationic polymer poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) were grafted from the pore wall of a 3DOM cross-linked polystyrene (3DOM CLPS-g-PDMAEMA) via surface-initiated atom transfer radical polymerization (SI-ATRP) and salicylic acid (SA) was employed as the model adsorbate. PDMAEMA chains can adopt a more extended conformation in water. Therefore, the adsorption capacity increases with the grafted amount due to the increasing number of adsorption sites and the extended chain conformation. The 3DOM CLPS-g-PDMAEMA exhibits a very high adsorption capacity towards SA (390 mg g−1 when the initial concentration of SA is 500 mg L−1) which is even higher than that of activated carbon. Moreover, the 3DOM adsorbent also exhibits a high adsorption selectivity between SA and phenol, and the selectivity coefficient for SA reaches 45.8 in the presence of phenol. The 3DOM adsorbent is also reusable and can be regenerated by sodium hydroxide solution. The results of fifteen adsorption–desorption cycles show that all the adsorption capacities maintain above 85% of the original SA loading capacity. We envision that novel 3DOM polymeric adsorption will play a significant role in developing a new generation adsorbent.

Design and functionality of colloidal-crystal-templated materials—chemical applications of inverse opals

Templating with colloidal crystals composed of monodisperse spheres is a convenient chemical method to obtain porous materials with well-ordered periodicity and interconnected pore systems. The three-dimensionally ordered macroporous (3DOM) products or inverse opals are of interest for numerous applications, both for the optical properties related to structural color of these photonic crystal materials and because of their bicontinuous nanostructure, i.e., a continuous nanostructured skeleton with large interfacial area and a three-dimensionally interconnected pore system with low tortuosity. This review outlines various synthetic methods used to control the morphology of 3DOM materials with different compositions. It highlights aspects of the choice of colloidal particles, assembly of the colloidal crystal template, infiltration and processing, template removal, and other necessary modifications to enhance the functionality of the materials. It also considers syntheses within the confinement of 3DOM materials and summarizes characterization methods that are particularly useful in the analysis of 3DOM materials. The review then discusses chemical applications of 3DOM materials, namely sorption and controlled release, optical and electrochemical sensors, solar cells, lithium ion batteries, supercapacitors, fuel cells, and environmental and chemical fuel catalysis. A focus is on structural features and materials properties that enable these applications.

Important Property of Polymer Spheres for the Preparation of Three-Dimensionally Ordered Macroporous (3DOM) Metal Oxides by the Ethylene Glycol Method: The Glass-Transition Temperature

We demonstrate that the glass-transition temperature (T(g)) of a polymer sphere template is a crucial factor in the production of three-dimensionally ordered macroporous (3DOM) materials. Metal nitrate dissolved in ethylene glycol-methanol was infiltrated into the void of a face-centered, close-packed colloidal crystal of poly(methyl methacrylate) (PMMA)-based spheres. The metal nitrate reacts with EG to form a metal oxalate (or metal glycoxylate) solid (nitrate oxidation) in the void of the template when the metal nitrate-EG-PMMA composite is heated. Further heating converts metal oxalate to metal oxide and removes PMMA to form 3DOM materials. We investigated the effect of T(g) of PMMA templates and obtained clear evidence that the solidification temperature of the metal precursor solution (i.e., nitration oxidation temperature) should be lower than the T(g) of the polymer spheres to obtain a well-ordered 3DOM structure.

Effects of pore size on the mechanical properties of three-dimensionally ordered macroporous nickel

The mechanical properties of three-dimensionally ordered macroporous (3DOM) nickel with pore sizes between 312 and 1200nm are explored under nanoindentation and microhardness tester. This paper demonstrates that the hardness and elastic modulus of 3DOM Ni increase as the pore size decreases. The phenomenon that “smaller is stronger” is mainly due to the combined effects of sharing the load with more and smaller pore cells, the decrease of the moment upon the small pore wall and larger surface area to volume ratio. The deformation process of 3DOM Ni is pore wall “fracture-dominated” under nanoindentation while “bending-dominated” under microhardness tester. The results demonstrate how pore size control at the microstructural scale can tailor hardness and elastic modulus and hold great potential for the design and application of new 3DOM materials and devices.

Maintaining the Structure of Templated Porous Materials for Reactive and High-Temperature Applications

Nanoporous and nanostructured materials are becoming increasingly important for advanced applications involving, for example, bioactive materials, catalytic materials, energy storage and conversion materials, photonic crystals, membranes, and more. As such, they are exposed to a variety of harsh environments and often experience detrimental morphological changes as a result. This article highlights material limitations and recent advances in porous materials--three-dimensionally ordered macroporous (3DOM) materials in particular--under reactive or high-temperature conditions. Examples include systems where morphological changes are desired and systems that require an increased retention of structure, surface area, and overall material integrity during synthesis and processing. Structural modifications, changes in composition, and alternate synthesis routes are explored and discussed. Improvements in thermal or structural stability have been achieved by the isolation of nanoparticles in porous structures through spatial separation, by confinement in a more thermally stable host, by the application of a protective surface or an adhesive interlayer, by alloy or solid solution formation, and by doping to induce solute drag.

Immobilization of Glucose Oxidase on Ordered Macroporous Silicas Functionalized with Amino Group

AbstractA novel glucose oxidase immobilized on three‐dimensionally ordered macroporous (3DOM) material has been prepared by firstly preparation of hybrid 3DOM SiO2‐NH2 materials using colloidal crystal method, and following covalent immobilization of glucose oxidase on the pore walls of the 3DOM materials. The materials were characterized by SEM, FTIR, DSC and BET techniques. SEM observation shows that the macropores are highly ordered and are interconnected by small windows. FTIR measurement shows that there are amino and organic groups in the pore walls. The surface area of the 3DOM SiO2‐NH2 material is about 10.2 m2/g. The loaded amount of enzyme is increased with amino content in the materials. The immobilized enzyme has high activity, thermal stability and can be reused.

Studies on late formation of 3D ordered macroporous materials through colloidal crystal templates

Three-dimensional ordered macroporous (3DOM) materials are anticipated to exhibit improved performance in lots of applications due to their special structure. This paper presents the formation mechanism of 3DOM structure during the removal process of templates, which has not been systematically studied yet. Using polymer colloidal crystal template, 3DOM metallic materials were prepared by electrochemical deposition and dissolution. The results indicate that windows in inverse opals are formed because of the associated breaking of thin wall materials. There seems to be a critical thickness for the same wall materials. The existence of windows improved the formation of 3DOM structures during the removal process of templates.

Construction and characterization of three-dimensionally ordered macroporous polystyrene equipped with pH-responsive switchable windows

Three-dimensionally ordered macroporous (3DOM) materials have a large pore volume and a uniformly distributed pore size. The macropores are interconnected with each other via “window” channels. A novel pH-responsive carrier system based on 3DOM material has been constructed by grafting pH-responsive polymeric chains from the pore wall of 3DOM cross-linked polystyrene (3DOM CLPS) via surface-initiated atom transfer radical polymerization to control the on–off action of the “window” channels. The grafted amounts can be controlled by variation of the solvent and the graft polymerization time. The functionalized 3DOM CLPS has a high pore volume and can store more guest molecules. Guest molecules such as vancomycin can be stored and released from the macropores of the functionalized 3DOM CLPS by changing pH values at will. The on–off action of “windows” at different pH values was confirmed by the storage–release experiments, which demonstrate that the level of vancomycin release from the functionalized 3DOM CLPS is strongly dependent on the pH value. The storage–release experiments of 3DOM CLPS-g-PAA with different grafted amounts and the 3DOM CLPS without grafting a polymer chain indicate that the introduced pH-responsive polymer chains act as a permeation valve on the connected windows. We envision that the new 3DOM material equipped with pH-responsive switchable windows can play a significant role in developing new generations of intelligent delivery materials, intelligent chromatographic sampling, and other molecular machines.

Three-dimensional ordered macroporous IrO2 as electrocatalyst for oxygen evolution reaction in acidic medium

Three-dimensional ordered macroporous (3-DOM) IrO2 was synthesized by using the silica colloidal crystal template method and explored as electrocatalyst for oxygen evolution reaction (OER) in acidic medium. X-Ray diffraction (XRD) patterns indicate that the prepared 3-DOM IrO2 has a rutile structure. Images of scanning and transmission electron microscopies suggest that the 3-DOM IrO2 possesses a hierarchical pore structure, in which the honeycomb array of 300 nm primary macropores were cross-linked by secondary mesopores on the walls. The presence of mesopores is also indicated by the N2 adsorption/desorption isotherms and the small-angle XRD patterns. As compared with IrO2 prepared by conventional colloidal method, the 3-DOM IrO2 exhibited much larger BET area and voltammetric charges. Accordingly, about two and half times enhancement in OER activity was achieved by using 3-DOM IrO2 as the electrode materials, showing prospect of 3-DOM materials in reducing the demand of the expensive IrO2 electrocatalyst for OER in water electrolysis.

Three‐dimensionally ordered macroporous cross‐linked polystyrene incorporating functional groups via hydrophilic spacer arms: Application for heavy metal ion adsorption

AbstractThree‐dimensionally ordered macroporous cross‐linked polystyrenes (3DOM CLPS) with 2‐mercaptobenzothiazole (MBZ) groups attached directly or via hydrophilic spacer arms to frameworks were prepared for use as heavy metal ion adsorbents. The hydrophilic spacer arms are polyethylene glycol (PEG) chains with three different lengths. The functionalized 3DOM CLPS were characterized by SEM, FTIR, and elemental analysis. The results confirm that the MBZ groups have been introduced onto the pore wall of 3DOM CLPS directly or via PEGs, and the ordered structure was well preserved after functionalization. The functionalized 3DOM CLPS are effective adsorbents for the removal of heavy metal ions from solution, with adsorption capacities ranging from 0.25 to 1.14 mmol/g for silver (I) ions and 0.28 to 0.51 mmol/g for mercury (II) ions, respectively. The introduction of hydrophilic spacer arms between the 3DOM frameworks and the heterocyclic functional groups improves the adsorption capacities and adsorption kinetics. The adsorption capacities increase with the length of spacer arm. After regeneration by washing with acidic thiourea solution, the metal ion adsorption capacities of the regenerated 3DOM materials were on around 90% of the original capacities. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Fabrication of three-dimensionally ordered macroporous Ta 2O 5 films through aqueous organic gel process

Ta 2O 5 thin films have been prepared in the forms of three-dimensionally ordered macroporous (3-DOM) materials through aqueous organic gel process guided by polystyrene (PS) colloidal templates. The structure of the films was strongly affected by the infiltration process. This suggests that the infiltration process which aims at introducing desired materials into the interstitial spaces between the PS templates is of critical importance. Dip-drawing method was adopted for infiltration in this article. However, excess precursor worked as a capping agent for films prepared from the precursor of high concentration. Spin-coating method can efficiently remove the excess precursor by high speed rotating, which makes it a promising process for the infiltration of Ta-citric precursor with concentration higher than 0.5 mol/L. X-ray diffraction (XRD) pattern showed that the products can crystallize at 600 °C and had a pure orthorhombic phase. The chemical composition of the product was also studied by X-ray photoelectron spectroscopy (XPS).

Preparation and formation mechanism of three-dimensionally ordered macroporous (3DOM) MgO, MgSO 4, CaCO 3, and SrCO 3, and photonic stop band properties of 3DOM CaCO 3

Three-dimensionally ordered macroporous (3DOM) magnesium (Mg) oxide (MgO), MgSO 4, calcium (Ca) carbonate (CaCO 3), and strontium (Sr) carbonate (SrCO 3) were prepared using a colloidal crystal of polymer spheres as a template. Ethanol or ethanol–water solution of metal salts (acetate or nitrate) and citric acid was infiltrated into the void of the colloidal crystal template of a monodispersed poly(methyl methacrylate) (PMMA) sphere. Heating of this PMMA–metal salt–citric acid composite produced the desired well-ordered 3DOM materials with a high pore fraction, which was confirmed by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ultraviolet-visible (UV–vis) diffuse reflectance spectra. The presence of citric acid is crucial for production of the 3DOM structures. Reaction of citric acid with metal salt produces metal citrate solid in the void of PMMA spheres, which is necessary to maintain the 3DOM structure during the calcination process. 3DOM CaCO 3 shows opalescent colors because of it's photonic stop band properties.

Preparation of three-dimensionally ordered macroporous perovskite materials

In this paper, we use La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 as examples to demonstrate a preparation method for three-dimensionally ordered macroporous (3DOM) perovskite thermochromic materials. Polystyrene spheres with an average diameter of 220 nm were self-assembled into a three-dimensionally ordered colloidal crystal template. A mixed metal nitrate solution prepared using La(NO3)3·6H2O, Ca(NO3)2·4H2O, Sr(NO3)2, Mn(CH3COO)2·4H2O and an ethanol precursor was used to fill the interstitial voids of the polystyrene colloidal crystal templates. 3DOM La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 materials were then obtained after the sphere templates were removed via drying and calcination. The results show that the framework of the 3DOM materials can have different thicknesses and pore shrinkage rates by varying the filling times. In addition, the Curie temperatures of the 3DOM and bulk La0.8Sr0.2MnO3 materials can be varied by altering the preparation method.

Preparation and Upconversion Luminescence of Three-Dimensionally Ordered Macroporous ZrO2: Er3+, Yb3+

The three-dimensionally ordered macroporous (3DOM) ZrO2: Er(3+), Yb(3+) materials were successfully synthesized by the sol-gel method combined with a polystyrene latex sphere templating technique, and their morphologies, surface physicochemical properties, and upconversion photoluminescence (UC-PL) properties were studied. The results indicate that the materials exhibited both porosity and strong UC-PL under the excitation of a 978 nm diode laser. In comparison with the nonporous samples, the relative intensity of the red ((4)F(9/2)-(4)I(15/2)) to the green ((4)S(3/2)/(2)H(11/2)-(4)I(15/2)) emission decreased visibly because of the decreased nonradiative relaxation in the 3DOM materials. It was also observed that the relative intensity of the green emission to the red emission increased significantly with the increasing excitation power. An indirect three-photon populating process occurred for the green emission as the excitation power and Yb(3+) concentration was high enough.