Synthesis and morphogenesis of organic polymer materials with hierarchical structures in biominerals

Synthesis and morphogenesis of polypyrrole (PPy) with hierarchical structures from nanoscopic to macroscopic scales have been achieved by using hierarchically organized architectures of biominerals. We adopted biominerals, such as a sea urchin spine and nacreous layer, having hierarchical architectures based on mesocrystals as model materials used for synthesis of an organic polymer. A sea urchin spine led to the formation of PPy macroscopic sponge structures consisting of nanosheets less than 100 nm in thickness with the mosaic interior of the nanoparticles. The morphologies of the resultant PPy hierarchical architectures can be tuned by the structural modification of the original biomineral with chemical and thermal treatments. In another case, a nacreous layer provided PPy porous nanosheets consisting of the nanoparticles. Conductive pathways were formed in these PPy hierarchical architectures. The nanoscale interspaces in the mesocrystal structures of biominerals are used for introduction and polymerization of the monomers, leading to the formation of hierarchically organized polymer architectures. These results show that functional organic materials with complex and nanoscale morphologies can be synthesized by using hierarchically organized architectures as observed in biominerals.     

Functional twin monomers and twin macro monomers as components for the synthesis of hierarchically nanostructured hybrid materials*

Internal polymeric soft templates are used for the polymerization of twin monomers (TM) to achieve nanostructured hybrid materials of desired morphology. For this purpose, oligomeric groups such as oligo(ethylene glycol) (OEG) or polymerizable ethenyl‐substituents were covalently linked to the silicon atom of TMs of the 4H‐benzo‐1,3,2‐dioxasiline type. These functionalized TMs are used in simultaneous twin polymerization in combination with the ideal TM 2,2'‐spirobi[4H‐1,3,2‐benzodioxasiline]. Nanostructure dimension can be adjusted in the range from 2 to 20 nm by the composition of the components used in hybrid material synthesis. Inorganic/organic hybrid material disks of interpenetrating networks with hierarchical nanostructures are available by polymerization in the melt which are potentially suitable as membrane devices. Physical properties such as brittleness, transparency, electrolytic stability, and barrier properties of the hybrid material could potentially be adjusted by changing both monomer composition and monomer structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2312–2320     

Co‐assembly of Patchy Polymeric Micelles and Protein Molecules

The development in the synthesis and self‐assembly of patchy nanoparticles has resulted in the creation of complex hierarchical structures. Co‐assembly of polymeric nanoparticles and protein molecules combines the advantages of polymeric materials and biomolecules, and will produce new functional materials. Co‐assembly of positively charged patchy micelles and negatively charged bovine serum albumin (BSA) molecules is investigated. The patchy micelles, which were synthesized using block copolymer brushes as templates, leads to co‐assembly with protein molecules into vesicular structures. The average size of the assembled structures can be controlled by the molar ratio of BSA to patchy micelles. The assembled structures are dissociated in the presence of trypsin. The protein–polymer hybrid vesicles could find potential applications in medicine.     

Co-assembly of Patchy Polymeric Micelles and Protein Molecules

The development in the synthesis and self-assembly of patchy nanoparticles has resulted in the creation of complex hierarchical structures. Co-assembly of polymeric nanoparticles and protein molecules combines the advantages of polymeric materials and biomolecules, and will produce new functional materials. Co-assembly of positively charged patchy micelles and negatively charged bovine serum albumin (BSA) molecules is investigated. The patchy micelles, which were synthesized using block copolymer brushes as templates, leads to co-assembly with protein molecules into vesicular structures. The average size of the assembled structures can be controlled by the molar ratio of BSA to patchy micelles. The assembled structures are dissociated in the presence of trypsin. The protein–polymer hybrid vesicles could find potential applications in medicine.     

Reactive Template Synthesis of Polypyrrole Nanotubes for Fabricating Metal/Conducting Polymer Nanocomposites

Unique nanocomposites of polypyrrole/Au and polypyrrole/Pt hybrid nanotubes are synthesized employing polypyrrole (PPy) nanotubes as an advanced support by solution reduction. The conducting polymer PPy nanotubes are fabricated by using pre‐prepared MnO₂ nanowires as the reactive templates. MnO₂ nanowires induce the 1D polymerization of pyrrole monomers and the simultaneous dissolution of the templates affords the hollow tube‐like structure. The loading content of metal nanoparticles in the nanocomposites could be adjusted by simply changing the amount of metal precursors. This work provides an efficient approach to fabricate an important kind of metal/conducting polymer hybrid nanotubes that are potentially useful for electrocatalyst and sensor materials.     

An Asymmetric Anion‐Pillared Metal–Organic Framework as a Multisite Adsorbent Enables Simultaneous Removal of Propyne and Propadiene from Propylene

The one‐step removal of multi‐component gases based on a single material will significantly improve the efficiency of separation processes but it is challenging, owing to the difficulty to precisely fabricate porous materials with multiple binding sites tailored for different guest molecules. Now a niobium oxide–fluoride anion‐pillared interpenetrated material ZU‐62 (NbOFFIVE‐2‐Cu‐i, NbOFFIVE=NbOF₅^2?) is presented. It features asymmetric O/F node coordination for the simultaneous removal of trace propyne and propadiene from propylene. The narrow distribution nanospace (aperture of Site I 6.75 Å, Site II 6.94 Å, Site III 7.20 Å) derived from the special coordination geometry within ZU‐62 customized the corresponding energy‐favorable binding sites for the propyne and propadiene that enable propadiene uptake (1.74 mmol g^?1) as well as excellent propyne uptake (1.87 mmol g^?1) under ultra‐low pressure (5000 ppm). The multisite capture mechanism was revealed by modeling studies.     

双模板法制备介孔／大孔复合孔结构硅胶独石

采用双模板法,向正硅酸甲酯的水解体系中同时引入聚乙二醇和三嵌段共聚物,成功制备出具有双连续大孔、同时孔壁中分布着有序介孔的复合孔结构硅胶独石材料. 产物的比表面积高达880 m2/g, 大孔孔径为0.2～5 μm, 介孔高度集中地分布在 5 nm. 结合物理吸附、扫描电镜、粉末X射线衍射和透射电镜等表征手段,发现合成条件如原料组成、反应温度和pH值等对反应体系中凝胶化转变和相分离发生的相对速度有重要影响,进而影响产物复合孔结构的生成. 此外,通过对合成条件的优化,一方面增强了无机骨架的强度,另一方面降低了湿凝胶干燥过程中的毛细管压力降,有效缓和了凝胶结构在干燥过程中的开裂和变形,使复合孔结构硅胶独石在厘米尺度内具有良好的整体性能.     

Synthesis and characterization of ultraviolet‐curable hyperbranched poly(siloxysilane)s

Two UV‐curable hyperbranched poly(siloxysilane)s ( I and III ) containing vinyl and allyl end groups were synthesized via polyhydrosilylation with methylbis(methylethylvinylsiloxy)silane and methylbis(dimethylallylsiloxy)silane monomers. A cationic UV‐curable hyperbranched polymer ( II‐Ep ) with epoxy end groups was prepared via the hydrosilylation of hyperbranched polymer II with Si? H terminated groups and glycidyl methacrylate, and II was also obtained via the polyhydrosilylation of AB₂‐type monomer methylvinylbis(methylethylsiloxy)silane. All hydrosilylation reactions were catalyzed by Pt/C or chloroplatinic acid. Three AB₂‐type monomers were synthesized via the hydrolysis of functional chlorosilane, which was prepared with Grignard reagents and dichlorosilane. The molecular structures of the polymers were characterized with ¹H NMR, Fourier transform infrared, and gel permeation chromatography, and the UV‐curing behaviors of the polymers under different atmospheres and with different photoaccelerators were also investigated. The thermostability of uncured and cured polymers was examined with thermogravimetric analysis, and the data indicated that the orders of the onset decomposition temperatures for the cured polymers and the residue weights were as follows: III (380 °C) > I (320 °C) > II‐Ep (280 °C) and I (70.4%) > III (64.1%) > II‐Ep (60.9%), respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1883–1894, 2005     

掺杂聚合物对溶致液晶结构的影响

利用聚合物大分子作构建组分,将其掺杂到不同类型表面活性剂构成的溶致液晶中,考察对液晶相结构的影响．利用小角X射线散射及偏光显微镜对聚合物掺杂前后液晶的结构进行表征,并讨论了聚合物与液晶模板间的相互作用．对阴离子型表面活性剂琥珀酸二异辛酯磺酸钠(AOT)／水液晶体系,聚合物的嵌入使层间距d增大;而对非离子表面活性剂十二烷基聚氧乙烯醚(C12EO4)／水体系,除小分子量的聚乙二醇PEG400外,其它聚合物嵌入使d减小,表明聚合物分子类型、大小及浓度对溶致液晶的结构参数甚至组装方式有不同的影响机制．     

Synthesis of Carbon–Nitrogen–Phosphorous Materials with an Unprecedented High Amount of Phosphorous toward an Efficient Fire‐Retardant Material

Phosphorus incorporation into carbon can greatly modify its chemical, electronic, and thermal stability properties. To date this has been limited to low levels of phosphorus. Now a simple, large‐scale synthesis of carbon–nitrogen–phosphorus (CNP) materials is reported with tunable elemental composition, leading to excellent thermal stability to oxidation and fire‐retardant properties. The synthesis consists of using monomers that are liquid at high temperatures as the reaction precursors. The molten‐state stage leads to good monomer miscibility and enhanced reactivity at high temperatures and formation of CNP materials with up to 32 wt % phosphorus incorporation. The CNP composition and fire‐retardant properties can be tuned by modifying the starting monomers ratio and the final calcination temperature. The CNP materials demonstrate great resistance to oxidation and excellent fire‐retardant properties, with up to 90 % of the materials preserved upon heating to 800 °C in air.     

受生物启发模拟合成生物矿物材料及其机理研究进展

自然界中存在大量复杂、高度功能化的生物矿物材料如贝壳、珍珠、牙齿、骨骼等,其中很多是非常普通的无机矿物材料。运用仿生合成的思路来制备形貌可控、结构特殊且具有独特性质的材料一直是交叉学科研究的热点,如何模拟生物矿化方法合成功能化材料,正逐渐引起科学界的关注。碳酸钙等生物矿物材料广泛存在于生物和地质体系中,对生物体的特异功能起着极其重要的作用。本文将重点回顾有关碳酸钙等生物矿物材料的生物模拟合成研究的进展。生物矿物合成的微环境主要包括模板和溶液相。本文即从这两方面着手,评述了近年来利用软、硬模板法模拟合成生物矿物的研究进展。     

Sequence‐Defined Oligomers from Hydroxyproline Building Blocks for Parallel Synthesis Applications

The functionality of natural biopolymers has inspired significant effort to develop sequence‐defined synthetic polymers for applications including molecular recognition, self‐assembly, and catalysis. Conjugation of synthetic materials to biomacromolecules has played an increasingly important role in drug delivery and biomaterials. We developed a controlled synthesis of novel oligomers from hydroxyproline‐based building blocks and conjugated these materials to siRNA. Hydroxyproline‐based monomers enable the incorporation of broad structural diversity into defined polymer chains. Using a perfluorocarbon purification handle, we were able to purify diverse oligomers through a single solid‐phase extraction method. The efficiency of synthesis was demonstrated by building 14 unique trimers and 4 hexamers from 6 diverse building blocks. We then adapted this method to the parallel synthesis of hundreds of materials in 96‐well plates. This strategy provides a platform for the screening of libraries of modified biomolecules.     

Synthesis and Characterization of Gold Nanoparticle‐Functionalized Ordered Mesoporous Materials

We report the synthesis and characterization of three different ordered mesoporous materials, labeled MCM‐48, SBA‐155, and SBA‐16 type materials, which were functionalized with gold nanoparticles using three different strategies. The functionalization strategies can be categorized as (i) in situ growth of gold nanoparticles, (ii) template loading, and (iii) diffusion loading of prefabricated gold nanoparticles. Two different particle sizes were employed in the latter two strategies, 5 nm and 10 nm. For all mesoporous structures, functionalization strategies, and particle sizes attempted, the materials retained their long‐range order upon incorporation of nanoparticles. From the adsorption isotherms, incorporation of gold nanoparticles altered the pore structure of the mesoporous support of some of the SBA‐15 and SBA‐16 type materials, with the effect on incorporation on the pore structure being particle size dependent in most cases. The majority of gold nanoparticles were found to reside on the external surface of the materials regardless of substrate and functionalization strategy; however, for the in situ synthesis and the template loading strategies, a significant fraction of the particles was determined to reside within the pore system of the material. In situ growth resulted in the highest content of gold nanoparticles in the solid phase. The relative effectiveness in retaining gold nanoparticles in the solid phase for each functionalization strategy was determined to be, in descending order, in situ synthesis, template loading, and diffusion loading.     

Synthesis and photoproperties of Eu(III)‐bearing star polymers as luminescent materials

Water‐soluble luminescent material was developed by introducing europium (Eu(III)) ions into the core of a star polymer. Living radical polymerization was used to obtain the star polymer. The strategy to introduce Eu(III) ions into the star polymer was studied using poly(methyl methacrylate) as an arm. The best Eu(III) ion introduction was obtained by simultaneous introduction, resulting in about 30 µmol/g‐polymer, which needed only one step for synthesis. The utilization of a hydrophilic polymer such as poly(ethylene oxide) (PEO) as an arm produced a water‐soluble star polymer. The Eu(III)‐bearing PEO star polymer obtained in this study was water soluble and showed fluorescence. In addition, it was stable in water after 1 month. The Eu(III)‐bearing star polymer exhibited luminescent properties under UV light irradiation with relatively high quantum yields of 60% in organic solution and 19% in aqueous solution. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2527–2535     

Synthesis and physical properties of highly branched perfluorinated polymers from AB and AB2 monomers

Highly branched perfluorinated aromatic polyether copolymers were prepared from the polycondensation of the AB₂ monomer, 3,5‐bis[(pentafluorobenzyl)oxy]benzyl alcohol with a variety of fluoroaryl and alkyl bromide AB comonomers. The structures and comonomer distribution of the resulting polymers were characterized in detail. ¹H NMR data from kinetic trials illustrated that perfluoroaryl AB comonomer distribution correlated to AB comonomer sterics. ¹⁹F NMR data revealed that fluorinated AB monomers and 3‐bromo‐1‐propanol AB monomers were distributed within the AB₂ polymer backbone, while longer alkyl bromide AB monomers, 6‐bromo‐1‐hexanol, were mostly distributed along hyperbranched polymer chain ends. In general, as AB comonomer incorporation increased for nonsterically hindered copolymers, thermal decomposition onset increased and glass transition temperatures decreased. The combined data demonstrated the effect of comonomer distribution and sterics on physical properties of AB₂‐based polymer systems. The resulting materials were used to cast thin polymer films for measurement of contact angle, which were shown to be directly related to comonomer content. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1880–1894     

Monodisperse polystyrene microspheres used as porogenes in the synthesis of polymer monoliths

Formation of a porous structure with the use of monodisperse polymer particles as templates is exemplified by the synthesis of two types of solid macroporous polymer materials featuring different hydrophobic-hydrophilic properties. The materials are prepared via the photo-induced free-radical copolymerization of monomers in the presence of pore-forming agents: strictly spherical polystyrene microspheres with various diameters and natures of the surface. Copolymer samples are analyzed via scanning-electron and atomic-force microscopy, mercury intrusion porosimetry (MIP), porosimetry based on the intraporous adsorption and desorption of gases (BET analysis), IR measurements, and solid-state NMR spectroscopy.     

Precision replication of hierarchical biological structures by metal oxides using a sonochemical method

A novel method for duplicating the hierarchical structures of biological substances at nanometer resolution in manganese oxides has been developed. This innovation uses natural biomorphic specimens, such as butterfly wing, cotton, and wood as templates. The biotemplates were first treated with either HCl/NaOH or HCl/H2O2/NaOH and then mixed with an aqueous solution of KMnO4. The treated biological materials were then ultrasonically irradiated, and finally, the biological templates were removed by calcination in air at temperatures between 500 and 800 degrees C. The structures of the resulting manganese oxides were characterized by a combination of XRD, FE-SEM, TEM and EDS. It was found that the fine hierarchical structures of the biological templates down to the nanometer scale were faithfully duplicated, and the duplication was positive. A mechanism for the positive replication is proposed and discussed in terms of the effects of the sonochemical reaction as well as the surface modification prior to the sonochemical reaction. The same sonochemical method can be extended to the duplication of intricate hierarchical structures of other biological forms in a large range of metal oxides.     

Structural colored gels for tunable soft photonic crystals

A periodically ordered interconnecting porous structure can be embodied in chemical gels by using closest‐packed colloidal crystals as templates. The interconnecting porosity not only provides a quick response but also endows the porous gels with structural color arising from coherent Bragg optical diffraction. The structural colors revealed by porous gels can be regulated by several techniques, and thus, it is feasible to obtain desirable, smart, soft materials. A well‐known thermosensitive monomer, N‐isopropylacrylamide (NIPA), and other minor monomers were used to fabricate various structural colored gels. The selection of minor monomers depended on the targeted properties. This review focuses on the synthesis of templates, structural colored porous gels, and the applications of structural colored gel as smart soft materials for tunable photonic crystals. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 87–105; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20169     

Anion Responsive Imidazolium‐Based Polymers

Stimuli responsiveness in polymer design is providing basis for diversely new and advanced materials that exhibit switchable porosity in membranes and coatings, switchable particle formation and thermodynamically stable nanoparticle dispersions, polymers that provide directed mechanical stress in response to intensive fields, and switchable compatibility of nanomaterials in changing environments. The incorporation of ionic liquid monomers has resulted in many new polymers based on the imidazolium group. These polymers exhibit all of the above‐articulated material properties. Some insight into how these anion responsive polymers function has become empirically available. Much opportunity remains for extending our understanding as well as for designing more refined stimuli‐responsive materials.     

Topochemical polymerization of diphenyldiacetylene-based materials and the relevant application in photocatalysis

Diphenyldiacetylene can be preorganized by self-assembly or external-templating, followed by topochemical polymerization under UV irradiation to form polydiphenyldiacetylene. Such a resulting polymer is a promising photocatalyst for organic pollutant degradation under visible light.