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Showing papers on "Surface modification published in 2010"


Journal ArticleDOI
TL;DR: This work aims to review different strategies of surface modification and functionalization of inorganic colloidal nanoparticles with a special focus on the material systems gold and semiconductor nanoparticles, such as CdSe/ZnS.
Abstract: Inorganic colloidal nanoparticles are very small, nanoscale objects with inorganic cores that are dispersed in a solvent. Depending on the material they consist of, nanoparticles can possess a number of different properties such as high electron density and strong optical absorption (e.g. metal particles, in particular Au), photoluminescence in the form of fluorescence (semiconductor quantum dots, e.g. CdSe or CdTe) or phosphorescence (doped oxide materials, e.g. Y(2)O(3)), or magnetic moment (e.g. iron oxide or cobalt nanoparticles). Prerequisite for every possible application is the proper surface functionalization of such nanoparticles, which determines their interaction with the environment. These interactions ultimately affect the colloidal stability of the particles, and may yield to a controlled assembly or to the delivery of nanoparticles to a target, e.g. by appropriate functional molecules on the particle surface. This work aims to review different strategies of surface modification and functionalization of inorganic colloidal nanoparticles with a special focus on the material systems gold and semiconductor nanoparticles, such as CdSe/ZnS. However, the discussed strategies are often of general nature and apply in the same way to nanoparticles of other materials.

1,477 citations


Journal ArticleDOI
TL;DR: The influence of surface modification of activated carbon with gaseous ammonia on adsorption properties toward carbon dioxide (CO2) was reviewed in this paper, where two different methods, heat treatment and ammonia treatment (amination) for producing activated carbon had been compared and amination was found to be suitable modification technique for obtaining efficient CO2 adsorbents.

853 citations


Journal ArticleDOI
Qiang Wei1, Fulong Zhang1, Jie Li1, Beijia Li1, Changsheng Zhao1 
TL;DR: Polydopamine-coating can be prepared in acidic, neutral and alkaline aqueous media by oxidant-induced polymerization, which is material-independent and multifunctional for surface modification as mentioned in this paper.

648 citations


Journal ArticleDOI
TL;DR: In this article, the authors highlight the recent advances on the chemical synthesis, surface modification and applications of rare earth fluoride nano-/microcrysals, with special emphasis on β-NaY(Gd)F4, F4, Yb3, Er3+ upconversion nanopaticles (UCNPs).
Abstract: This feature article highlights the recent advances on the chemical synthesis, surface modification and applications of rare earth fluoride nano-/microcrysals. In the past decade, great progress in the size and shape control of rare earth fluoride nano-/microcrystals has been made by developing solution phase-based methods such as thermal decomposition, hydro(solvo)thermal reaction, hydrothermal in situ conversion route, and ionic liquids-based synthesis. The main challenge of fluoride nanocrystals for biological applications is that it is hard to obtain ideal nanocrystals with smaller size (sub-50 nm), higher luminescence yield, better dispersity and stability in aqueous solvents, and superior biocompatibility. In order to overcome these shortcomings, a series of strategies of surface modification have been outlined in this review. Finally, we introduce the application of rare earth fluorides, with special emphasis on β-NaY(Gd)F4 : Yb3+, Er3+ upconversion nanopaticles (UCNPs) in biomedical applications including biological labels, multimodal bioimaging, photodynamic therapy and drug delivery.

630 citations


Journal ArticleDOI
Sook Hee Ku1, Jungki Ryu1, Seonki Hong1, Haeshin Lee1, Chan Beum Park1 
TL;DR: It is found that the poly(dopamine) coating can promote cell adhesion on any type of material surfaces including the well-known anti-adhesive substrate, poly(tetrafluoroethylene).

619 citations


Journal ArticleDOI
TL;DR: In this article, surface coating of cathode materials has been widely investigated to enhance the life and rate capability of lithium-ion batteries and the surface coating discussed here was divided into three different configurations which are rough coating, core shell structure coating and ultra thin film coating.
Abstract: Surface coating of cathode materials has been widely investigated to enhance the life and rate capability of lithium-ion batteries. The surface coating discussed here was divided into three different configurations which are rough coating, core shell structure coating and ultra thin film coating. The mechanism of surface coating in achieving improved cathode performance and strategies to carry out this surface modification is discussed. An outlook on atomic layer deposition for lithium ion battery is also presented.

572 citations


Journal ArticleDOI
TL;DR: The functionalization procedure presented in this work allows high versatility and flexibility in tailoring the surface chemistry of nanocarbon material to specific needs in catalysis as well as electronic device materials.
Abstract: The surface chemical properties and the electronic properties of vapor grown carbon nanofibers (VGCNFs) have been modified by treatment of the oxidized CNFs with NH3. The effect of treatment temperature on the types of nitrogen functionalities introduced was evaluated by synchrotron based X-ray photoelectron spectroscopy (XPS), while the impact of the preparation methods on the surface acid−base properties was investigated by potentiometric titration, microcalorimetry, and zeta potential measurements. The impact of the N-functionalization on the electronic properties was measured by THz-Time Domain spectroscopy. The samples functionalized via amination are characterized by the coexistence of acidic and basic O and N sites. The population of O and N species is temperature dependent. In particular, at 873 K nitrogen is stabilized in substitutional positions within the graphitic structure, as heterocyclic-like moieties. The surface presents heterogeneously distributed and energetically different basic sites....

556 citations


Journal ArticleDOI
Eun-Young Choi1, Tae Hee Han1, Jihyun Hong1, Ji-Eun Kim1, Sun Hwa Lee1, Hyun Wook Kim1, Sang Ouk Kim1 
TL;DR: In this article, a stable dispersion of reduced graphene in various organic solvents was achieved via noncovalent functionalization with amine-terminated polymers, which was obtained by chemical reduction of graphene oxide in aqueous media and was vacuum filtered to generate reduced graphene sheets.
Abstract: Stable dispersion of reduced graphene in various organic solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aqueous dispersion of reduced graphene was prepared by chemical reduction of graphene oxide in aqueous media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a solubility test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polystyrene was noncovalently functionalized to the graphene, while graphene sheets were phase transferred via sonication from aqueous phase to the organic nonsolvent phase, including the amine-terminated polymers. Thorough FTIR and Raman spectroscopy investigation verified that the protonated amine terminal group of polystyrene underwent noncovalent functionalization to the carboxylate groups at the graphene surface, providing the high dispersibility in various organic media.

539 citations


Journal ArticleDOI
01 May 2010-Carbon
TL;DR: In this paper, the surface, interfacial and dispersion properties of carbon nanotubes (CNTs), and the mechanical properties of the CNT/epoxy composites affected by CNT functionalization are investigated.

512 citations


Journal ArticleDOI
18 Mar 2010-Langmuir
TL;DR: It is demonstrated that the enzyme immobilization on the GO sheets could take place readily without using any cross-linking reagents and additional surface modification.
Abstract: Graphene oxide (GO), having a large specific surface area and abundant functional groups, provides an ideal substrate for study enzyme immobilization. We demonstrated that the enzyme immobilization on the GO sheets could take place readily without using any cross-linking reagents and additional surface modification. The atomically flat surface enabled us to observe the immobilized enzyme in the native state directly using atomic force microscopy (AFM). Combining the AFM imaging results of the immobilized enzyme molecules and their catalytic activity, we illustrated that the conformation of the immobilized enzyme is mainly determined by interactions of enzyme molecules with the functional groups of GO.

492 citations


Journal ArticleDOI
TL;DR: There has been considerable interest in the application of photochromism to photo-responsive systems which has led to the development of new tailored smart materials for photonics and biomedical fields as discussed by the authors, and the underlying principles behind photoresponsive behavior, subsequent applications and relevant examples.

Journal ArticleDOI
TL;DR: In this paper, the surface of the PMMA grafted graphene oxide (GPMMA) was characterized by AFM, HRTEM, Raman, FTIR and contact angle.
Abstract: Graphene is a two-dimensional new allotrope of carbon, which is stimulating great curiosity due to its superior mechanical, electrical, thermal and optical properties. Particularly attractive is the availability of bulk quantities of graphene (G) which can be easily processed by chemical exfoliation, yielding graphene oxide (GO). The resultant oxygenated graphene sheets covered with hydroxyl, epoxy and carboxyl groups offer tremendous opportunities for further functionalization opening plenty of opportunities for the preparation of advanced composite materials. In this work poly(methyl methacrylate) (PMMA) chains have been grafted from the GO surface via atom transfer radical polymerization (ATRP), yielding a nanocomposite which was soluble in chloroform. The surface of the PMMA grafted GO (GPMMA) was characterized by AFM, HRTEM, Raman, FTIR and contact angle. The interest of these novel nanocomposites lies in their potential to be homogenously dispersed in polymeric dense matrices and to promote good interfacial adhesion, of particular relevance in stress transfer to the fillers. PMMA composite films were prepared using different percentages of GPMMA and pristine GO. Mechanical analysis of the resulting films showed that loadings as low as 1% (w/w) of GPMMA are effective reinforcing agents, yielding tougher films than pure PMMA films and even than composite films of PMMA prepared with GO. In fact, addition of 1% (w/w) of GPMMA fillers led to a significant improvement of the elongation at break, yielding a much more ductile and therefore tougher material. Thermal analysis showed an increase of the thermal stability properties of these films providing evidence that strong interfacial interactions between PMMA and GPMMA are achieved. In addition, AFM analysis, in friction force mode, is demonstrated to be an effective tool to analyse the surface filler distribution on polymer matrices.

Journal ArticleDOI
23 Aug 2010-Langmuir
TL;DR: A simple surface modification method results in strong covalent bonds between α-Al(2)O(3) supports and imidazolate ligands, which promote the heterogeneous nucleation and growth of ZIF crystals.
Abstract: Zeolitic imidazolate frameworks (ZIFs) are hybrid organic-inorganic microporous materials that exhibit zeolite-like structures and can be synthesized with a wide range of pore sizes and chemical functionality. ZIFs as thin films and membranes are of interest for their applications in sensors and gas separation. Here, we report a method for ZIF film and membrane fabrication, based on support surface modification and in situ solvothermal growth, which has potential for general application to other ZIF membranes. Our simple surface modification method results in strong covalent bonds between α-Al(2)O(3) supports and imidazolate ligands, which promote the heterogeneous nucleation and growth of ZIF crystals. The microstructure of ZIF-8 films can be controlled by controlling the pH of the growth solution. ZIF-7 films were fabricated to demonstrate the potential for general applicability of our method. Finally, the separation performance of several ZIF-8 membranes was evaluated, revealing molecular sieving behavior with an ideal selectivity for H(2)/CH(4) of 13.

Journal ArticleDOI
TL;DR: A bio-inspired approach for superhydrophobic surface modification was investigated, and the superHydrophobic-hydrophilic alternating surface was generated by the method combined with soft-lithography.
Abstract: A bio-inspired approach for superhydrophobic surface modification was investigated. Hydrophilic conversion of the superhydrophobic surface was easily achieved through this method, and the superhydrophobic-hydrophilic alternating surface was generated by the method combined with soft-lithography. The resulting patterned surface showed high water adhesion property in addition to superhydrophobic property.

Journal ArticleDOI
TL;DR: In this article, surface functionalization of multi-walled carbon nanotubes (MWCNTs) by ethylenediamine, via chemical modification of carboxyl groups, using O-(7-azabenzotriazol-1-yl)-N,N, N′,N′-tetramethyluronium hexafluorophosphate, was performed.

01 Jan 2010
TL;DR: In this paper, a method of simultaneous reduction and surface funcionalization of graphene oxide by a one-step poly(norepinephrine) funcionalisation was presented, which can be a useful platform for graphene-based ano-composites.
Abstract: his study presents a method of simultaneous reduction and surface funcionalization of graphene oxide by a one-step poly(norepinephrine) funcionalization. The pH-induced aqueous functionalization of graphene oxide y poly(norepinephrine), a catecholamine polymer inspired by the robust dhesion of marine mussels, chemically reduced and functionalized graphene xide. Moreover, the polymerized norepinephrine (pNor) layer provided mulifunctionality on the reduced graphene oxide that includes surface-initiated olymerization and spontaneous metallic nanoparticle formation. This facile urface modifi cation strategy can be a useful platform for graphene-based ano-composites.

Journal ArticleDOI
TL;DR: Thermogravmetric analysis (TGA) shows that the nondestroyed graphene structure provides greater thermal stability not only for the grafted molecules but also, more importantly, for the graphene itself, compared to the free-radical grafting method.
Abstract: When fabricated by thermal exfoliation, graphene can be covalently functionalized more easily by applying a direct ring-opening reaction between the residual epoxide functional groups on the graphene and the amine-bearing molecules. Investigation by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM) all confirm that these molecules were covalently grafted to the surface of graphene. The resulting dispersion in an organic solvent demonstrated a long-term homogeneous stability of the products. Furthermore, comparison with traditional free radical functionalization shows the extent of the defects characterized by TEM and Raman spectroscopy and reveals that direct functionalization enables graphene to be covalently functionalized on the surface without causing any further damage to the surface structure. Thermogravmetric analysis (TGA) shows that the nondestroyed graphene structure provides greater thermal stability not only for the grafted molecules but als...

Journal ArticleDOI
TL;DR: This critical review looks at how the functionalization of solid substrates by self-assembly processes provides the possibility to tailor their surface properties in a controllable fashion.
Abstract: In this critical review, we look at how the functionalization of solid substrates by self-assembly processes provides the possibility to tailor their surface properties in a controllable fashion. One class of molecules, which attracted significant attention during the past decades, are silanes self-assembled on hydroxyl terminated substrates, e.g. silicon and glass. These systems are physically and chemically robust and can be applied in various fields of technology, e.g., electronics, sensors, and others. The introduction of chemical functionalities in such monolayers can be generally obtained via two methods. This involves either the use of pre-functionalized molecules, which can be synthesized by different synthetic routes and subsequent self-assembly of these moieties on the surface. The second method utilizes chemical surface reactions for the modification of the monolayer. The latter method offers the possibility to apply a large variety of different organic reaction pathways on surfaces, which allows the introduction of a wide range of terminal end groups on well-defined base monolayers. In contrast to the first approach an important advantage is that the optimization of the reaction conditions for suitable precursor molecules is circumvented. The following review highlights a selection of chemical surface reactions, i.e., nucleophilic substitution, click chemistry and supramolecular modification, which have been used for the functionalization of solid substrates (80 references).

Journal ArticleDOI
Hyehyeon Kim1, Saehee Kim1, Chiyoung Park1, Hyemi Lee1, Heon Joo Park1, Chulhee Kim1 
TL;DR: Mesoporous silica nanoparticles have been demonstrated to be excellent hosts for molecules of various sizes, shapes, and functionalities and to provide Si-MPs with unique properties for stimuli-responsive controlled delivery applications.
Abstract: Mesoporous silica nanoparticles (Si-MPs) have been demonstrated to be excellent hosts for molecules of various sizes, shapes, and functionalities. [ 5 ] The organically functionalized Si-MPs have unique structural features such as environmentally stable mesoporous structures, large surface area, tunable pore size, and well-defi ned surface properties. [ 3 ] In particular, the facile surface functionalization of Si-MPs and their effi cient internalization into cells provided Si-MPs with unique properties for stimuli-responsive controlled delivery applications. [ 2 , 4 ]

Book ChapterDOI
01 Jan 2010
TL;DR: In this article, the fundamental principles governing laser propagation and absorption as well as the resulting material responses are discussed, and two case studies of improving efficiency in photovoltaic and optoelectronic devices are presented.
Abstract: Lasers provide the ability to accurately deliver large amounts of energy into confined regions of a material in order to achieve a desired response. For opaque materials, this energy is absorbed near the surface, modifying surface chemistry, crystal structure, and/or multiscale morphology without altering the bulk. This chapter covers a brief introduction to the fundamental principles governing laser propagation and absorption as well as the resulting material responses. We then highlight two case studies of improving efficiency in photovoltaic and optoelectronic devices as well as optimizing cell-surface interactions in biological interfaces.

Journal ArticleDOI
Jinhong Jiang1, Liping Zhu1, Xiao-Lin Li1, You-Yi Xu1, Bao-Ku Zhu1 
TL;DR: The results of in vitro hemocompatibility test proved that surface heparinization significantly suppressed the adhesion of platelet and enhanced the anticoagulation ability of PE membranes.

Journal ArticleDOI
TL;DR: This critical review aims to bring together the available wet-chemical routes toward the formation of silicon-organic monolayers under ambient conditions and discusses the reasons behind the need for novel chemical approaches that are straightforward, modular and of wide scope so as to allow the application of silicon electrodes in aqueous electrolytes.
Abstract: Organic functionalization of non-oxidized silicon surfaces, while allowing for robust chemical passivation of the inorganic substrate, is intended and expected to broaden the chemical, physical and electronic properties of the currently most relevant technological material. Numerous protocols are now available for the preparation of Si–C, Si–O and Si–N bound layers. In particular, the covalent attachment of 1-alkenes and 1-alkynes onto hydride-terminated Si(100) and Si(111) has seen a wealth of research activity starting from the pioneering work of Linford and Chidsey (Alkyl monolayers covalently bonded to silicon surfaces, J. Am. Chem. Soc., 1993, 115(26), 12631–12632). This critical review aims to bring together the available wet-chemical routes toward the formation of silicon–organic monolayers under ambient conditions. Particular emphasis is placed on discussing the reasons behind the need for novel chemical approaches that are straightforward, modular and of wide scope so as to allow the application of silicon electrodes in aqueous electrolytes. A general introduction to biomolecular recognition events at functionalized silicon surfaces is also presented (281 references).

Journal ArticleDOI
TL;DR: The development in the area of surface modification of polymeric synthetic membranes since 2000 is reviewed in this paper, where many patents, articles, and reviews have been written on the development of surface modifications for polymeric membranes.
Abstract: The development in the area of surface modification of polymeric synthetic membranes since 2000 is reviewed. Many patents, articles, and reviews have been written on the development in the area of surface modification of polymeric synthetic membranes subjected to RO, UF, NF, gas separation (GS), and biomedical applications, mainly since 2000, but recently more attention has been given to the modification of their surfaces to obtain desirable results. In particular, most emphasis has been given to plasma treatment, grafting of polymers on the surface, and modifying the surfaces by adding SMMs (surface-modifying molecules). New additives are synthesized to make the polymeric membrane surfaces either to be more hydrophilic or hydrophobic, aimed at improvement in selectivity and permeability of the membranes for GS, NF, and RO. Improvement in antifouling by surface modification is also a popular topic in the membrane industries. In the last 8 years, tremendous research efforts have been made on the development of antifouling membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Journal ArticleDOI
TL;DR: It is expected that suspension stability, interfacial interactions, friction, and other properties of grafted CNCs can be controlled by changes in temperature and provide a unique platform for further development of stimuli-responsive nanomaterials.

Journal ArticleDOI
22 Nov 2010
TL;DR: The fabrication, characterization, and properties of biomaterials such as ceramics, metals, and polymers with nanostructured surfaces are reviewed.
Abstract: After biomaterials are implanted into the human body, there are inevitable interactions between the biological environment and implant surfaces. Therefore, the surface of biomaterials has become one of the hottest research topics. Nanotechnology is a powerful tool in modern materials science and able to incorporate biomimicry on the nanoscale into materials engineering. Therefore, research on nanotechnology/nanostructured biomaterials has attracted much attention. A nano-functionalized surface has promising biological properties and clinical applications of biomaterials can be improved by producing a nanostructured surface. Many surface modification techniques have been adopted to produce nano-functionalized biomaterials surface, and in this paper, the fabrication, characterization, and properties of biomaterials such as ceramics, metals, and polymers with nanostructured surfaces are reviewed.

Journal ArticleDOI
TL;DR: In this article, three zwitterionic polymers including poly(N,N-dimethyl-N-(p-vinylbenyl)-N-(3-sulfopropyl) ammonium) (PDMVSA), poly(2-(methacryloyloxyethyl) ethyl-dimmethyl-(3sulfophosphorylcholine) ammonium (PDMMSA), and poly (2-methacetyl-oxyethyl phosphoryl choline) (PMPC) were successfully grafted from cellul

Journal ArticleDOI
TL;DR: Using the reactivity of polydopamine films to immobilize VEGF onto metal substrates may provide a promising approach for application in situations where revascularization around implants would be beneficial in improving bone healing and implant integration.

Journal ArticleDOI
TL;DR: In this article, ultrathin layers of Al2O3 were deposited via atomic layer deposition (ALD) on SnO2 photoanodes used in dye-sensitized solar cells featuring the I3−/I− couple as the re...
Abstract: We report here the exploitation of ultrathin layers of Al2O3 deposited via atomic layer deposition (ALD) on SnO2 photoanodes used in dye-sensitized solar cells featuring the I3−/I− couple as the re...

Journal ArticleDOI
TL;DR: In this paper, the behavior of colloidal mesoporous silica (CMS) nanoparticles was investigated in simulated biological fluid with the aim of gaining new insights about the reactivity of the CMS when brought into contact with biological media that simulate the human plasma, in view of drug delivery applications.

Journal ArticleDOI
TL;DR: The results indicate that cassava peel waste can potentially be applied as a raw material for the production of low cost-high performance activated carbon electrode materials for Electric Double Layer Capacitors (EDLCs).