Dual reaction capacity of hydrogenated nanodiamond

High temperature hydrogen stream treatment of nanodiamond was shown to produce nanodiamond with bifunctional surface. OH- and different CH-groups were shown to be the main functional groups on the surface. In this article we proposed two main strategies for further chemical modification of hydrogenated nanodiamond. OH-groups were shown to react with different types of acylating agents: anhydrides and chloranhydrides. Chlorination of hydrogenated nanodiamond with molecular chlorine and its subsequent treatment with alkyllithium reagents resulted in formation of alkyl-nanodiamonds. Chlorination was shown to reduce the size of nanodiamonds aggregates. We have also applied suspension-state NMR-H1 spectroscopy to study suspensions of alkyl-nanodiamonds for the first time.     

Suface grafting of polymers onto nanodiamond by ligand-exchange reaction of ferrocene moieties of polymers with polycondensed aromatic rings of the surface

To improve the dispersibility of nanodiamond (ND) in solvents and polymer matrices, the grafting of copolymers containing vinyl ferrocene (Vf) onto the surface by a ligand-exchange reaction with ferrocene moieties of the copolymer and polycondensed aromatic rings of ND surface was investigated. The copolymer containing Vf was prepared by the radical copolymerization of Vf with vinyl monomers, such as methyl methacrylate (MMA), styrene (St), and N-isopropylacrylamide (NIPAM), using 2, 2′-azobisisobutyronitrile as an initiator. It was found that by heating of ND with poly(Vf-co-MMA), poly(Vf-co-St), and poly(Vf-co-NIPAN) in the presence of AlCl₃ and Al powder as catalysts, the corresponding copolymer was successfully grafted onto the surface. On the contrary, in the absence of AlCl₃, no grafting of these copolymers was observed. The grafting of polymers onto the ND surface was confirmed by FT-IR. These polymer-grafted NDs were found to give stable dispersions in solvents for the grafted polymer. In addition, the dispersibility of poly(Vf-co-NIPAM)-grafted ND uniformly dispersed in water below 32 °C but precipitated above the temperature. Therefore, it was concluded that the dispersibility of ND in water could be controlled by the temperature of water.     

Surface functionalization of nanodiamond particles via atom transfer radical polymerization

Ultradispersed diamond (UDD)/polymer brushes having excellent solution dispersibilities are prepared by atom transfer radical polymerization (ATRP) using the “grafting-from” synthesis strategy. ATRP initiators, covalently attached to oxidized surface carbon atoms of UDD aggregates using esterification chemistry, initiate polymerization of methacrylate monomers to form hydrophobic UDD/poly(iso-butyl methacrylate) and UDD/poly(tert-butyl methacrylate) polymer brushes. Acid hydrolysis of a UDD/poly(tert-butyl methacrylate) polymer brush affords a hydrophilic UDD/poly(methacrylic acid) polymer brush. Based on surface area measurements and GPC data, the calculated surface density of a representative UDD/polymer brush material is ca. five polymer chains/100 nm². A wide variety of UDD/polymer brush materials having controlled dispersibility and functional group reactivity are now potentially available using this synthesis strategy.     

State of C-atoms on the modified nanodiamond surface

XPS, EEL, Auger and FTIR spectroscopies were used to testify the influence of chemical treatment upon the state of C-atoms in the core and on the surface of nanodiamond particles. The study was carried out with ND (JSC “Diamond Centre”). The different kinds of treatments were done ex-situ: with air (5 h) at 200 and 400 °C; with hydrogen (5 h) at 800, 850 and 900 °C; with fluorine (48 h) at 20 °C and 0.5 atm. Noticeable change was not found in the state of C-atoms both on the surface and up to 10 monolayers after these treatments. The concentration of F in the sample is equal to  9 at.%. The binding energy of the F 1s differs from the one in functional groups— –CF₂, –CF. Nevertheless FTIR spectra show bands that can be related to С–О, С–F bonds.     

Surface functionalization by smart coatings: Stimuli-responsive binary polymer brushes

Heterogeneous binary polymer brushes consist of an assembly of polymer chains of two incompatible polymers that are attached by one end to the surface with sufficient grafting density. They have been investigated experimentally only for a short time. Those brushes can be used in the form of ultrathin polymeric layers as a versatile tool for surface engineering to tune physico-chemical surface characteristics as wettability, surface charge, chemical composition or morphology, and furthermore to create switchable and responsive surface properties. For the fabrication of these layers “grafting-from” (as radical polymerization at the interface) and “grafting-to” (as tethering of the polymer chains from solution) methods were developed and investigated in detail.     

Surface layer formation on Sn anode: ATR FTIR spectroscopic characterization

Surface layer formed on Sn thin film electrode in 1 M LiPF₆/EC:DMC electrolyte was characterized using ex situ FTIR spectroscopy with the attenuated total reflection technique. IR spectral analyses showed that the immersion of Sn film in the electrolyte resulted in a chemical interfacial reaction leading to the passivation of Sn surface with primarily PF-containing inorganic surface species and small amount of organics. When constant current cycling was conducted with lithium cells with Sn film electrode at 0.1-1.0 V vs. Li/Li⁺, the interfacial reaction between Sn and electrolyte appeared significantly intensified that the features of PF-containing species became enhanced and new IR features of organic species (e.g. alkyl carbonate/carboxylate metal salts and ester functionalities) were observed. The surface layer continued to form with cycling, partly due to non-effective surface passivation as well as particle pulverization accompanied by enlargement of active surface area. Comparative IR spectral analyses indicated that the interfacial reaction between Sn and PF₆⁻ anion played a leading role in forming the surface layer, which is different from lithiated graphite that had mainly organic surface species. The data contribute to a better understanding of the interfacial processes occurring on Sn-based anode materials in lithium-ion batteries.     

TATB粒子表面改性研究

利用物理（微波和紫外光辐照）方法处理TATB炸药的表面,使TATB粉末表面被部分活化,达到TATB粒子表面改性的目的。研究表明：经过微波处理和UV光辐照对TATB粒子进行改性,TATB的表面性能被改善,吸附、润湿性能增强,与粘结剂的作用力提高。微波处理是通过高能粒子对TATB的表面“刻蚀”作用,使表面粗糙度增大,新生表面积扩大;UV光辐照是使TATB的表面活性中心偏移,TATB分子中－NO2的部分空轨道被电子填充,使－NO2与粘结剂间的作用有所增强;但在H2O2存在的条件下进行UV光辐射后,又经超声波处理的效果最好。     

纳米氧化锌表面包覆二氧化硅的性能研究

采用直接沉淀法制备了纳米ZnO,以ZnSO4·7H2O和Na2CO3为原料,并用硅酸钠水解生成的SiO2对其进行了表面包覆改性。通过采用红外吸收光谱（FT-IR）,X射线衍射（XRD）对改性前后的ZnO进行表征。结果表明,ZnO表面形成的包覆物是以非晶态形式存在的,改性后纳米ZnO对紫外光的屏蔽性能有所下降,光催化活性明显下降,进一步证明了纳米ZnO颗粒表面存在二氧化硅包覆层,使纳米ZnO稳定化。     

滑石粉表面改性填充PP复合体系研究

采用钛酸酯、铝酸酯、硼酸酯及硅烷偶联剂,对滑石粉进行表面改性处理,通过接触角、活化率、吸油量和红外谱图等试验方法对改性效果进行了评定;检测滑石粉填充PP复合体系的力学性能,进一步说明了偶联剂种类和填料粒径对复合材料力学性能的影响。结果表明:活化改性后,填料表面的极性和官能团均发生了变化;硅烷和钛酸酯偶联剂改性滑石粉效果较好,1250目滑石粉填充体系的综合力学性能最优。     

Hydrophilic surface formation on polymers by ion-assisted reaction

The wettability and adhesion of various polymers were improved using ion-assisted reaction (IAR) method, in which the polymer surfaces were irradiated by energetic ions in a reactive gas environment. The addition of new polar groups on polymer surfaces and permanent wettable polymer surfaces (water contact angle below 30° and surface free energy 60–70 mJ/m²) have been accomplished by IAR treatment. The changes in wettability and surface free energy were critically dependent on the ion dose, the ion beam energy and the flow rate of the reactive gas. Improvements in wettability and surface free energy are primarily attributed to the increase of polar components due to the formation of polar groups such as –(C=O)–, –(C=O)–O–, –(C–O)–, etc. The characteristics of the IAR treatment have been reviewed, with outstanding results regarding the wettability and adhesion of various polymers from polyolefin to fluoropolymers.     

Acrylonitrile-based copolymer membranes containing reactive groups: Surface modification by the immobilization of biomacromolecules

Asymmetric membranes fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) were immobilized with heparin and/or insulin to improve their surface properties. These biomacromolecule-immobilized PANCMA membranes were prepared by the amination of the membrane surface with ethylenediamine, followed by the reaction of the amino groups with heparin and/or insulin in the presence of 1-ethyl-3-(3-dimethyl amidopropyl) carbodiimide. The surface-modified membranes were analyzed by X-ray photoelectron spectroscopy to confirm the immobilization of the biomacromolecules. Morphological changes on the membrane surface and in the cross section were characterized by scanning electron microscopy. The surface hydrophilicity and hemocompatibility of the studied membranes were evaluated on the basis of water contact angle, platelets adhesion and cell attachment measurements. It was found that, after the immobilization of the biomacromolecules, the water contact angle and the amount of adhered platelets and macrophages on the membrane decreased significantly when compared with the nascent ones, indicating the improvement of surface hydrophilicity. Furthermore, the heparin immobilized membrane showed the best hemocompatibility among the corresponding membranes studied.     

纳米氧化镁粉体表面改性技术的研究进展

简述了纳米氧化镁表面改性的原因,并对纳米氧化镁的表面改性方法(物理改性和化学改性法):即表面包覆改性法、表面化学改性法、机械力化学改性法、沉淀反应改性法、外膜层改性(胶囊)法、和高能表面改性法进行了概述.着重介绍了表面活性剂、偶联剂在纳米氧化镁表面改性方面的应用,并对纳米氧化镁改性方面的研究提出了建议.     

Surface grafting polymerization and modification on poly(tetrafluoroethylene) films by means of ozone treatment

Surface modification on polytetrafluoroethylene (PTFE) films was performed with sequential hydrogen plasma/ozone treatments and surface-initiated polymerization. C-H groups were introduced to the surface of PTFE films through defluorination and hydrogenation reactions under hydrogen plasma treatment. The C-H groups then served as ozone accessible sites to form peroxide groups under ozone treatment. Grafting polymerization initiating from the peroxide groups was performed on the PTFE film surface with using acrylamide, acrylic acid, glycidyl methacrylate and 2-(2-bromoisobutyryloxy)ethyl acrylate (BIEA) as monomers. With utilizing the isobutylbromide groups on the surface of PTFE-g-PBIEA film as initiators, sodium 4-styrenesulfonate (NaSS) was polymerized onto the PTFE film surface via atom transfer radical polymerization, to bring arborescent macromolecular structure to PTFE film surface. The chemical structures of the macromolecules on PTFE film surfaces were characterized with FTIR-ATR, SEM-EDX and XPS. The surface hydrophilicities of modified PTFE films were significantly enhanced with the modification.     

Chemical modification of diamond surface with linoleic acid by using benzoyl peroxide

In this study, the introduction of the C=C bond, which is known to be chemically active, on diamond surface was attempted using a reaction with unsaturated fatty acid. The chemical reactivity of a hydrogenated diamond surface with linoleic acid, which was most effective for introducing of the C=C bond, using benzoyl peroxide was investigated in detail. The diamond surface modified with the C=C bond was used as the substrate for the surface-modified diamond. Different radical source such as NCS, NBS, AIBN, and TEMPO were allowed to react with the diamond surface treated with linoleic acid. After the reaction with NCS, NBS, or AIBN, IR peaks at 3011 cm^− 1, which correspond to the C-H bond on the C=C bond, significantly decreased in size, and XPS spectra showed that the elements that derived from the reacted radical source, that is Cl, Br, or N, existed on the diamond surface. On the other hand, after the reaction with TEMPO no XPS peak of the N atoms appeared although the IR peak at 3011 cm^− 1 slightly decreased. These experimental results indicate that the C=C bond introduced on diamond surface can participate in chemical reaction. The method used in this study could become a very useful technique if the coverage factor of the C=C bond is improved by optimization of the reaction condition.     

Nano-ATH的表面改性及其在ABS中的应用

选用钛酸酯偶联剂对纳米氢氧化铝(nano-ATH)进行表面改性,以改善其在丙烯腈-丁二烯-苯乙烯共聚物(ABS)中的分散性。利用透射电镜(TEM)表征了nano-ATH的改性效果,研究了改性条件对nano-ATH/ABS复合材料性能的影响。结果表明:在偶联剂用量2.5%,改性时间25min,改性温度80℃的条件下,nano-ATH/ABS复合材料的综合性能较好,改性后nano-ATH的分散性得到改善。     

纳米TiO2表面改性及表征研究

采用不同种类的钛酸酯偶联剂和硅烷偶联剂对纳米TiO2进行表面改性试验,利用FTIR红外光谱仪等分析手段,研究发现改性后的纳米TiO2粒子表面已引入有机基团,使纳米TiO2的亲油化度和活化指数分别达到54.34％和99.51％,有效地改善了纳米TiO2与有机介质的相容性,使其在有机相中均匀分散.实验结果表明,在以甲苯为溶剂的体系中,最佳反应条件为:偶联剂用量5％,反应时间120 min,反应温度120℃.     

Facile functionalization of soybean oil by thiol-ene photo-click reaction for the synthesis of polyfunctional acrylate

Nowadays biosource-based materials have received revitalized interest for their ability to substitute for petrochemical-based materials. In this paper, we report a facile synthetic method of soybean oil-based polyfunctional acrylate (PFA) for UV-curable materials. Specifically, rapid and highly efficient side-chain functionalization of soybean oil was achieved via photoclick thiol-ene reaction, soybean oil-based polycarboxylic acid (PCA) was thus obtained. Next, by DCC (N,N′-dicyclohexylcarbodiimide) catalyzed esterification reaction with hydroxypropyl acrylate, polyfunctional acrylate (PFA) was synthesized at room temperature. Real-FTIR result indicated that almost 100% conversion of double-bond within vegetable oil was observed within 16.7 min, yielding the soybean oil-based polycarboxylic acid quantitatively. Furthermore, the structure of PFA was confirmed by ¹H NMR and FTIR. Finally, the excellent UV-curing rate of PFA was revealed by real-FTIR.     

钠钙硅玻璃表面改性的ESCA研究

本文通过处理液浸渍钠钙硅系统玻璃对其表面进行改性，采用ＥＳＣＡ研究了钠钙硅系统玻璃在表面改性前后其表面结构的变化。研究表明：钠钙硅系统玻璃在表面改性后其表面形成了一层有机物多分子层，由此探讨了钠钙硅系统玻璃表面改性的机理。     

Surface modification of halogenated polymers. 4. Functionalisation of poly(tetrafluoroethylene) surfaces by diazonium salts

Reduced PTFE can be grafted by nitro and bromo-phenyl diazonium tetrafluoroborate salts in a manner similar to that used for carbon, except that no application of a reductive potential during grafting was required. Grafting was evidenced by cyclic voltammetry, X-ray fluorescence or ToF-SIMS. Nitro- and bromo-phenyl moieties were covalently linked to the PTFE material and could be eliminated only by abrasion.     

Surface Modification of Inorganic Oxide Particles with a Carbene Complex of Palladium: A Recyclable Catalyst for the Suzuki Reaction

The reaction of 1-(2,4,6-trimethylbenzyl)-3-(propyltriethoxysilane)imidazolidinium chloride, with the Pd(OAc)₂ complex proceeded smoothly in DMSO to give the bis[1-(2,4,6-trimethylbenzyl)-3-(propyltriethoxysilane)imidazolidin-2-ylidene]dichloropalladium(II) complex that was grafted onto the surface of amorphous silica. The effects of various factors, such as reaction temperature and time, on the grafting efficiency was evaluated. Inorganic oxide particles that were modified with a carbene complex of palladium(II) were tested for catalytic activity in the Suzuki coupling reaction between phenylboronic acid and several aryl halides.