掺铒联吡啶钌为探针分子压敏漆的制备及氧猝灭特性

以2,2′-联吡啶,三氯化钌(RuCl3),氯化铒(ErCl3)为原料合成了铒掺杂的探针分子。将探针分子加入到铕掺杂的硅溶胶基质中获得了铕、铒共掺杂的压敏漆样品。采用IR,SEM,EDS及荧光发射光谱对探针分子和压敏漆进行了表征。红外光谱结果表明,探针分子中联吡啶的结构没有被破坏。扫描电镜观察发现探针分子呈片状,EDS测试发现探针分子表面含有Er,Ru等元素。紫外吸收光谱表明压敏漆的最佳吸收波段位于200~500 nm处,选择410 nm作为激发光源,压敏漆在590 nm处有很强的荧光发射,并且随着空气压力的增大(即氧分子浓度的增加),压敏漆的荧光发射强度降低,说明压敏漆具有较好的氧猝灭特性。     

Development of solvent-free acrylic pressure-sensitive adhesives

The present publication describes a problem to develop solvent-free acrylic pressure-sensitive adhesives (PSA). Solvent-free PSA are established materials for the manufacturing of various self-adhesive products. Only by means of these acrylic PSA was it possible to succeed in drafting the present surprisingly efficient generation of double-sided pressure-sensitive adhesive tapes, medical products, protective masking films, films for the graphics market, and various specialty products. New applications and technical specifications stimulate the continuous development of new methods of polymerization of solvent-free acrylates. New syntheses of solvent-free acrylic PSA include polymerization in the reactor with removal of the solvent and polymerization on the carrier. The polymerization process is connected with UV-crosslinking.     

镧、铒共掺杂压敏漆的制备及荧光特性

以联吡啶,氯化钌,氯化镧,氯化铒为原料合成了镧、铒共掺杂的探针分子.将探针分子加入到硅溶胶基质中获得了镧、铒共掺杂的压敏漆样品.采用IR,SEM,XPS及荧光发射光谱对探针分子和压敏漆进行了测试分析.红外光谱测试结果表明,探针分子中联吡啶的结构没有被破坏.扫描电镜观察发现探针分子呈花瓣状,XPS测试发现压敏漆中含有Er,La,Ru等元素,说明稀土元素确实被掺入到压敏漆中.紫外吸收光谱表明压敏漆的最佳吸收波段位于200 ～ 500 nm处,选择410 nm作为激发光源,压敏漆在590 nm处有很强的荧光发射,并且随着空气压力的增大即氧分子浓度的增加,压敏漆的荧光强度降低,说明压敏漆具有较好的氧猝灭特性.     

A reversible water-based electrostatic adhesive

Commercial adhesives typically fall into two categories: structural or pressure sensitive. Structural glues rely on covalent bonds formed during curing and provide high tensile strength whilst pressure-sensitive adhesives use physical bonding to provide weaker adhesion, but with considerable convenience for the user. Here, a new class of adhesive is presented that is also reversible, with a bond strength intermediate between those of pressure-sensitive and structural adhesives. Complementary water-based formulations incorporating oppositely charged polyelectrolytes form electrostatic bonds that may be reversed through immersion in a low or high pH aqueous environment. This electrostatic adhesive has the advantageous property that it exhibits good adhesion to low-energy surfaces such as polypropylene. Furthermore, it is produced by the emulsion copolymerization of commodity materials, styrene and butyl acrylate, which makes it inexpensive and opens the possibility of industrial production. Bio-based materials have been also integrated into the formulations to further increase sustainability. Moreover, unlike other water-based glues, adhesion does not significantly degrade in humid environments. Because such electrostatic adhesives do not require mechanical detachment, they are appropriate for the large-scale recycling of, e.g., bottle labels or food packaging. The adhesive is also suitable for dismantling components in areas as varied as automotive parts and electronics.     

Electrodeposition and physicomechanical properties of coatings and foil of copper reinforced with nanosize aluminum oxide

Method of electrosynthesis of composite coatings and foil composed of copper reinforced with nanosize aluminum oxide is described. A method for chemical dispersion of aluminum oxide by the top-down principle and an electrolyte composition are suggested, which provide synthesis of composite materials with varied content of the modifying phase. The results of mechanical tests indicate that the plasticity, strength, and a number of other physicomechanical properties of thus synthesized composite materials are improved.     

The future of aluminum chemistry

This article represents a survey of current aluminum chemistry and some predictions regarding what type of aluminum chemistry will be conducted in the year 2000 and after. Because of the abundance and availability of aluminum in the earth, research incorporating this element will always be of importance to applications that impact on daily life. Indeed, applied chemistry is the primary goal of most aluminum research. It is likely that three broad areas of aluminum chemistry, catalysis, materials synthesis, and biological studies, will see substantial activity in the future. The use of aluminum in materials will continue in step with the growth of materials science, in general. In contrast, the use of aluminum compounds in catalysis and in effecting synthetic transformations will see a spectacular increase. This is a result of an increased understanding of the chemistry of aluminum, and the availability of a wide range of compounds containing aluminum which was been achieved over the past few decades during a period of increased attention to Main Group chemistry. In the coming years a clear understanding of the influence of aluminum on biological systems will almost certainly be obtained based upon the quality and amount of effort that has focused on this area in recent times.     

高效液相色谱-质谱法测定压敏胶及其制品中9种邻苯二甲酸酯

采用高效液相色谱-质谱( HPLC - MS)法,对压敏胶及其制品中的9种邻苯二甲酸酯进行同时测定.以乙酸乙酯为溶剂溶解压敏胶,甲醇沉淀高聚物,以3 000 r/min离心5min,清液定容后,用HPLC -MS分析检测.采用Xterra-Phenyl色谱柱,流动相为乙腈-水,流速为1 mL/min,选择离子监测.在优...     

Contribution of relaxation processes to adhesive-joint strength of viscoelastic polymers

Relaxation processes accompany all stages of the lifetime of viscoelastic pressure-sensitive polymer adhesives, which can form strong adhesive joints with substrates of various chemical natures under application of a slight external pressure to the adhesive film for a few seconds. This review deals with comparison of the adhesion and relaxation properties of a number of typical pressure-sensitive adhesives based on polyisobutylene, butyl rubber, styrene-isoprene-styrene triblock copolymers, alkyl acrylate copolymers, and silicone adhesives as well as pressure-sensitive adhesives based on blends of high-molecular-mass polyvinylpyrrolidone with oligomeric poly(ethylene glycol). Within all three stages of the lifetime of adhesive joints (under adhesive-bond-forming pressure, upon withdrawal of contact pressure in the course of relaxation of the adhesive material, and under the force detaching an adhesive film from the substrate surface), the strength of adhesive joints has been shown to be controlled by large-scale relaxation processes, which are characterized by long relaxation times in the range 150–800 s. All examined pressure-sensitive adhesives can be arbitrarily divided into two groups. The first group is composed of fluid adhesives that relax comparatively fast and exhibit no residual (unrelaxed) stress. The second group includes elastic adhesives capable storing mechanical energy in the course of deformation that are characterized by appreciably longer relaxation times and display residual stress after relaxation. Conditions of adhesive debonding (e.g., strain amplitude and deformation velocity) significantly affect the relaxation process.     

Unique thermal behavior of acrylic PSAs bearing long alkyl side groups and crosslinked by aluminum chelate

An acrylic pressure-sensitive adhesive (PSA), bearing octadecyl acrylate, methyl acrylate and acrylic acid groups, and crosslinked by aluminum acetylacetonate (AlACA), displayed behavior unique among acrylic PSAs in that its adhesion, which decreases with an increase in temperature, began to increase again from around 150 °C. In order to understand this behavior, the structure and thermal properties of the PSA were investigated in detail, along with another PSA crosslinked by a covalent crosslinking agent (Az). From thermal mechanical analysis, the PSA with ionic crosslinks (AlACA) showed three softening points at 20, 60, and 160 °C. In comparison, the PSA covalently crosslinked by Az only exhibited two softening points (at 20 and 60 °C). The softening point at 160 °C is clearly related to ionic chelate crosslinking. DSC measurements indicated that the softening point at 20 °C resulted from melting of the ordered octadecyl group, and the softening point at 60 °C was due to an increase in the mobility of the main chain. The temperature dependence of viscoelastic measurements revealed that the viscosity of the PSA crosslinked by AlACA increased at around 160 °C. From these results, we considered that the distinctive adhesion of the PSA crosslinked by AlACA could be due to ligand exchange at the aluminum crosslinking points, which are chelated by carboxy groups built in the main chain.     

Preparation and physical properties of flame retardant acrylic resin containing nano-sized aluminum hydroxide

Poly(methylmethacrylate) (PMMA) shows high strength and transparency but is a flammable material. In this study, the surface of aluminum hydroxide was modified with methacrylate containing phosphoric acid moieties before dispersion in MMA, and organic-inorganic nano-hybrid materials were obtained by bulk polymerization in the presence of the surface-modified aluminum hydroxide. The resulting hybrid materials retained the high transparency of PMMA, with transparency values similar to that of pure PMMA. Moreover, the flame resistance of the hybrid materials was improved in comparison with that of pure PMMA, with depression of the horizontal burning rate becoming a maximum at an inorganic content of 3 wt%. These results suggest that the use of aluminum hydroxide surface-modified with phosphoric acid groups is an efficient method for obtaining good performance fire-resistant polymer materials.     

Photoreactive UV-crosslinkable solvent-free acrylic pressure-sensitive adhesives containing copolymerizable photoinitiators based on benzophenones

The design and development of new, tailor-made, novel photoreactive acrylic pressure-sensitive adhesives, which can cope with both the technical and ecological demands, is therefore a continuing challenge for industrial research and development. Progress in the coating technology and the development of improved photoreactive acrylic adhesive will open the door for new applications and an extended market penetration of UV-crosslinkable acrylic adhesive raw materials containing unsaturated copolymerizable photoinitiators incorporated into the polymer backbone. They are characterized by good tack, good adhesion, excellent cohesion and very high shrinkage resistance. In this paper it is shown the application of H-abstractor such as 4-acryloyloxy benzophenone to obtain of the UV-crosslinked acrylic PSA.The presented novel UV-crosslinkable acrylic hotmelt PSA combines the economic advantages of the hotmelt coating technology with the high performance characteristics of the acrylic chemistry, including an excellent aging resistance, optical transparency and heat resistance.     

Tailoring the porous hierarchy and the tetrahedral aluminum content by using carboxylate ligands: hierarchically structured macro-mesoporous aluminosilicates from a single molecular source

A novel yet facile synthesis pathway has been developed for the design of hierarchically structured macro-mesoporous aluminosilicates with high aluminum content at tetrahedral sites using a single molecular bifunctional alkoxide (sec-BuO)(2)-Al-O-Si(OEt)(3) precursor. The use of carboxylate ligands and a highly alkaline media slow down the polymerization rate of the aluminum alkoxide functionality, thus permitting the preservation of the intrinsic Al-O-Si linkage. The hierarchically structured porous aluminosilicate materials present an unprecedented low Si/Al ratio close to 1. Heat treatment applied to the synthesized material seems to favor the incorporation of aluminum into tetrahedral position (intraframework aluminum species). The macro-mesoporosity was spontaneously generated, without the use of any external templating agent, by the hydrodynamic flow of the solvents released during the rapid hydrolysis and condensation processes of this double alkoxide. This method results in materials with an open array of interconnected macrochannels. The synthesized aluminosilicate materials with tailorable macro-mesoporous hierarchy and very high Al content at tetrahedral position hold huge promise in various applications as catalysts, catalysts supports, or adsorbents.     

Analytical characterization of polymers used in conservation and restoration by ATR-FTIR spectroscopy

In the last few decades many new polymers have been synthesized that are now being used in cultural heritage conservation. The physical and chemical properties and the long-term behaviors of these new polymers are determined by the chemical composition of the starting materials used in their synthesis along with the nature of the substances added to facilitate their production. The practical applications of these polymers depend on their composition and form (foam, film, sheets, pressure-sensitive adhesives, heat-seal adhesives, etc.). Some materials are used in restoration works and others for the exhibition, storage and transport of works of art. In all cases, it is absolutely necessary to know their compositions. Furthermore, many different materials that are manufactured for other objectives are also used for conservation and restoration. The technical information about the materials provided by the manufacturer is usually incomplete, so it is necessary to analytically characterize such materials. FTIR spectrometry is widely used for polymer identification, and, more recently, ATR–FTIR has been shown to give excellent results. This paper reports the ATR-FTIR analysis of samples of polymeric materials used in the conservation of artworks. These samples were examined directly in the solid material without sample preparation.     

Flexible,high sensitive and radiation-resistant pressure-sensing hydrogel

Excellent radiation resistance is a prerequisite for pressure-sensitive hydrogels to be used in high-energy radiation environments. In this work, tannic acid-modified boron nitride nanosheet（BNNS-TA） is first prepared as the radiation-resistant additive by a facile one-step ball milling of hexagonal boron nitride and tannic acid. Then, polyacrylamide（PAAm）-based pressure-sensitive hydrogel doped with BNNS-TA and Fe³⁺ions is fabricated. The ternary BNNS-TA/Fe³⁺/PAAm hydrogel...     

Dispersity of materials obtained by mechanical activation and laser sintering of Al-C systems and used for production of electrochemical capacitors

Characteristics of materials designed for electrodes of electrochemical capacitors based on mechanically activated Al-C composites applied onto aluminum foil by laser sintering are considered. The methods of X-ray diffraction, X-ray photoelectron spectroscopy, and transmission and scanning electron microscopy are used to study the structure and composition of synthesized layers. It is established that mechanical activation of aluminum in the presence of graphite followed by high-speed laser sintering of the obtained material on an aluminum foil substrate noticeably increases material dispersity with a rise in its specific surface area from an initial value of 4 m²/g to a value on the order of 1000 m²/g, as estimated from the data on the capacity of the electrical double layer.     

Properties and structural features of nanodisperse powder fillers

Comparative characteristics of polymer materials based on epoxy binder reinforced by disperse and fiber fillers are given. The structural features of nanopowders of aluminum oxide and copper are considered with the aim to use them as nanofillers of polymer materials. The dependence of structures of nanopowders under investigation on the change of their specific surface is shown. The fractional composition of aluminum oxide is analyzed, and particle sizes of fine and coarse fractions are found.     

Synthesis, characterization, and growth rates of aluminum- and Ge,Al-substituted silicalite-1 materials grown from clear solutions

The synthesis, characterization, and growth rates of aluminum- and germanium,aluminum-substituted silicalite-1 (Al-silicalite-1, Ge,Al-silicalite-1) materials grown from clear solutions are reported. In the case of aluminum substitution, the crystallinity of the materials as determined by powder X-ray diffraction (PXRD) decreases with increasing aluminum content, as does the micropore volume determined by nitrogen adsorption and the growth rate determined by in situ small-angle X-ray scattering (SAXS). The final materials possess slightly lower Si/Al ratios than the initial synthesis mixtures based on X-ray fluorescence analysis. In the case of simultaneous incorporation of germanium and aluminum, the final materials have a slightly lower Si/Al ratio than the synthesis mixture but a much higher Si/Ge ratio, indicating the aluminum is more readily incorporated in the zeolite as compared to germanium. This result is consistent with studies of individual heteroatom substitution behavior. Germanium incorporation in the final material increases at higher heteroatom contents (Si/(Ge+Al) = 50 and 25). The promoting effect of germanium on the growth rate of silicalite-1 dominates at low heteroatom content (Si/(Ge+Al) = 100), leading to enhanced zeolite growth rates as compared to pure silicalite-1. This promoting effect is insensitive to the Ge/Al ratio at a Si/(Ge+Al) = 100. The influence of aluminum on the growth rate, as well as the crystallinity of final materials, becomes observable when the heteroatom content is increased (Si/(Ge+Al) = 50 and 25). This is the first study we are aware of that reports the synthesis of Ge,Al-substituted silicalite-1 phases formed in hydroxide media or from clear solutions and has implications for the synthesis of nanoparticulate zeolitic materials for catalysis.     

Thermal degradation of butyl acrylate-methyl acrylate-acrylic acid-copolymers

The thermal degradation of copolymers based on butyl acrylate-methyl acrylate-acrylic acid used as acrylic pressure-sensitive adhesives, especially for bonding of plasticizer containing materials, has been investigated using thermogravimetry and pyrolysis-gas chromatography at 250°C. It was observed that during the pyrolysis of butyl acrylate-methyl acrylate-acrylic acid copolymers unsaturated monomers as methyl acrylate, methyl methacrylate, butyl acrylate and butyl methacrylate were formed. During the side-chain butyl acrylate-methyl-acrylate-acrylic acid-copolymer degradation the presence of methyl alcohol and butyl alcohol was observed.     

An All‐Solid‐State Fiber‐Shaped Aluminum–Air Battery with Flexibility,Stretchability, and High Electrochemical Performance

Owing to the high theoretical energy density of metal–air batteries, the aluminum–air battery has been proposed as a promising long‐term power supply for electronics. However, the available energy density from the aluminum–air battery is far from that anticipated and is limited by current electrode materials. Herein we described the creation of a new family of all‐solid‐state fiber‐shaped aluminum–air batteries with a specific capacity of 935 mAh g⁻¹ and an energy density of 1168 Wh kg⁻¹. The synthesis of an electrode composed of cross‐stacked aligned carbon‐nanotube/silver‐nanoparticle sheets contributes to the remarkable electrochemical performance. The fiber shape also provides the aluminum–air batteries with unique advantages; for example, they are flexible and stretchable and can be woven into a variety of textiles for large‐scale applications.     

An All‐Solid‐State Fiber‐Shaped Aluminum–Air Battery with Flexibility,Stretchability, and High Electrochemical Performance

Owing to the high theoretical energy density of metal–air batteries, the aluminum–air battery has been proposed as a promising long‐term power supply for electronics. However, the available energy density from the aluminum–air battery is far from that anticipated and is limited by current electrode materials. Herein we described the creation of a new family of all‐solid‐state fiber‐shaped aluminum–air batteries with a specific capacity of 935 mAh g^?1 and an energy density of 1168 Wh kg^?1. The synthesis of an electrode composed of cross‐stacked aligned carbon‐nanotube/silver‐nanoparticle sheets contributes to the remarkable electrochemical performance. The fiber shape also provides the aluminum–air batteries with unique advantages; for example, they are flexible and stretchable and can be woven into a variety of textiles for large‐scale applications.