Schmitt V., Ravaine V.,
Curr. Opin. Colloid Interface Sci. 2013, 18, 532–541. Review

Colloidal gel particles called microgels have shown their ability to adsorb at an oil–water interface and stabilise emulsion named Pickering emulsions. Such particles are soft, deformable, and porous, and they can swell or contract under the action of an external stimulus. These specificities make them emulsifiers of special interest as they offer a large versatility to emulsions and materials elaborated thereof. This modularity is in counterpart at the origin of an abundant and often contradictory literature. The aim of this paper is to review recent advances in the emulsion stabilisation mechanism, particularly focusing on the microgel conformation at the interface in relation with the mechanical interface behaviour and the emulsion macroscopic stability. A sum up of the unambiguous knowledge is also proposed as well as few central questions that remain to be answered to in the domain.

 

CurrOpCollInterSci2013 p532 TOC

Husken N., Taylor R. W., Zigah D., Taveau J.-C., Lambert O., Scherman O. A., Baumberg J. J., Kuhn A.,
Nano Lett. 2013, 13, 6016–6022.

One-dimensional (1D) nanoparticle chains with defined nanojunctions are of strong interest due to their plasmonic and electronic properties. A strategy is presented for the assembly of 1D gold-nanoparticle chains with fixed and rigid cucurbit[n]uril-nanojunctions of 9 Å. The process is electrokinetically accomplished using a nanoporous polycarbonate membrane and controlled by the applied voltage, the nanoparticle/CB[n] concentration ratio, time and temperature. The spatial structure and time-resolved analysis of chain plasmonics confirm a growth mechanism at the membrane nanopores.

 

NanoLett2013 p6016 TOC

Destribats M., Wolfs M., Pinaud F., Lapeyre V., Sellier E., Schmitt V., Ravaine V.,
Langmuir 2013, 29, 12367–12374.

This work reports a new evidence of the versatility of soft responsive microgels as stabilizers for Pickering emulsions. The organization of microgels at the oil–water interface is a function of the preparation pathway. The present results show that emulsification energy can be used as a trigger to modify microgel deformation at the oil–water interface and their packing density: high shear rates bring strong flattening of the microgels, whereas low shear rates lead to dense monolayers, where the microgels are laterally compressed. As a consequence, the resulting emulsions have opposite behavior in terms of flocculation, which arises from bridging between neighboring drops and is strongly dependent on their surface coverage. This strategy can be applied to any microgel which can sufficiently adsorb at low shear rates, i.e. small microgels or lightly cross-linked ones. The control of the organization of microgels at the interface does not only modify emulsion end-use properties but also constitutes a new tool for the development of Janus-type microgels, obtained by chemical modification of the adsorbed microgels.

 

Langmuir2013 p12367 TOC

Chen K., Adam C., Sojic N., Schmittel M.,
RSC Adv. 2013, 33, 24140–24145.

For remote Hg2+ detection, an array of nanotips was covalently functionalised using a versatile photochemical approach. After chemical etching of an optical fiber bundle to generate the nanotip array, a protected n-propyl amine was grafted onto the tip surface by silanisation and thereafter photodeprotected by irradiation at 365 nm. The new rhodamine-based probe 9 developed for detection of Hg2+ was linked to the liberated amino group using the HOBt/DCC protocol. The optical fiber bundles functionalised with 9 exhibited a high selectivity toward Hg2+in situ, in full analogy to its precursor 4 in solution. Titration of the functionalised optical fiber bundles using a remote detection mode showed a detection range from 10−5 to 5 × 10−3 M for mercury ions in aqueous medium.

 

RSCAdv2013 p24140 TOC

Suraniti E., Kanoufi F., Gosse C., Zhao X., Dimova R., Pouligny B., Sojic N.,
Anal. Chem. 2013, 85, 8902–8909. Editors' Highlight !

Latex micrometric beads are manipulated by optical tweezers in the vicinity of an ultramicroelectrode (UME). They are optically trapped in solution and approached the electrode surface. After the electrochemical measurement, they are optically removed from the surface. The residence time of the particle on the electrode is thus controlled by the optical tweezers. The detection is based on diffusional hindrance by the insulating objects which alters the fluxes of the redox Ru(NH3)63+ species toward the UME and thus its mass-transfer limited current. We have optically deposited successively 1, 2, and 3 beads of 3-μm radius on the UME surface, and we have recorded the variations of the current depending on their landing locations that were optically controlled. Finally we decreased the current by partially blocking the electroactive surface with a six-bead assembly. The variation of the steady-state current and the approach curves allow for the indirect electrochemical localization of the bead in the vicinity of the UME, not only when the bead is in contact but also when it is levitated at distances lower than the UME radius. These experiments show that single particles or more complex structures may be manipulated in situ in a contactless mode near the UME surface. From comparison with simulations, the electrochemical detection affords an indirect localization of the object in the UME environment. The developed approach offers a potential application for interrogating the electrochemical activity of single cells and nanoparticles.

 

AnalChem2013 p8902 TOC

Thumbnail Loget G., Kuhn A.Nature Comm. 20112, 535 Externally triggered motion of small objects shows a general promise in applications ranging from micromachines to drug delivery and self-assembly of...
Thumbnail Loget G., Kuhn A.G.I.T. Laboratory Journal 20115-6, 19-21. Bipolar electrochemistry is a concept with a quite long history, but has only very recently revealed its virtues in the field...
Thumbnail Couedelo L., Vaysse C., Guy A., Gosse I., Durant T., Pinet S., Simon N., Cansell M., Combe N.Lipid Nutri+ 2011, 12 La dernière édition des apports nutritionnels conseillés pour la population...
Thumbnail Destribats M., Lapeyre V., Sellier E., Leal-Calderon F., Schmitt V., Ravaine V.Langmuir 2011, 27(23), 14096-14107 Emulsions were prepared using poly(N-isopropylacrylamide) microgels as...
Thumbnail Peyrard L., Chierici S., Pinet S., Batat P., Jonusauskas G., Pinaud N., Meyrand P., Gosse I.Org. Biomol. Chem. 2011, 9, 8489-8494 A new strategy to obtain fluorescent cyclotriveratrylene (CTV) probes...
Thumbnail Loget G., Peyrard L., Ung V., Abadie T.L'Actualité Chimique 2011, 355, 50-51 La section Aquitaine de la Société Chimique de France inclut depuis janvier 2011 un club de jeunes chimistes qui a...
Thumbnail Bon Saint-Côme Y., Lalo H., Wang Z., Etienne M., Gajdzik J., Kohring G-W., Walcarius A., Hempelmann R., Kuhn A.Langmuir 2011, 27, 12737-12744 We describe the elaboration of a multi-scale tailored...
Thumbnail Ancla C., Lapeyre V., Gosse I., Catargi B., Ravaine V.Langmuir 2011, 27, 12693-12701 We report on the synthesis of various glucose-responsive microgels based on N-alkylacrylamide derivatives and...
Thumbnail Sojic N., Kuhn A.Annales de la Société des Experts Chimistes de France 2011975, 35-41. Les capteurs sont devenus indispensables pour de nombreux aspects de notre vie avec des exemples...
Thumbnail Segan D., Vukicevic R. D., Segan S., Sojic N., Buriez O., Manojlovic D.Electrochimica Acta 201156, 9968-9972 Cyclic voltammetry and ultramicroelectrodes were used to investigate the kinetic...
Thumbnail Loget G., Kuhn A.GIT Laborfachzeitschrift2011, 4, 236. Die bipolare Elektrochemie hat zwar schon einen ziemlich langen Werdegang hinter sich, ihre Vorteile auf dem Gebiet der Nanowissenschaft...
Thumbnail Wang Z., Etienne M., Kohring G-W., Bon Saint-Côme Y., Kuhn A., Walcarius A.Electrochim. Acta.2011, 56, 9032 We report here that the electrochemically-assisted deposition (E-AD) of silica thin...
Thumbnail Olariu C. I., Yiu H. H. P., Bouffier L., Nedjadi T., Costello E., Williams S. R., Halloran C. M., Rosseinsky M. J.J. Mater. Chem.2011, 21, 12650-12659 Amine and carboxylic acid-bifunctionalized iron...
Thumbnail Destribats M., Lapeyre V, Wolfs M., Sellier E., Leal-Calderon F., Ravaine V., Schmitt V.Soft Matter 2011, 7, 7689-7698  We synthesised soft uncharged microgels made of...
Thumbnail Loget G., Kuhn A.Techniques de l'Ingénieur2011, 7,RE208 L'électrochimie bipolaire est une technique relativement peu connue qui attire de plus en plus l'attention de la communauté scientifique....
Thumbnail Milutinovic M., Suraniti E., Studer V., Mano N., Manojlovic D., Sojic N.Chem. Comm.2011, 47, 9125-9127 Photoinitiated polymerization is efficiently and rapidly carried out to immobilize...
Thumbnail Milutinovic M., Sallard S., Manojlovic D., Mano N., Sojic N.Bioelectrochemistry2011, 82, 63-68 In this work, we report a new sensing approach based on electrogenerated chemiluminescence (ECL) in an...
Thumbnail Meunier A., Jouannot O., Fulcrand R., Fanget I., Bretou M., Karatekin E., Arbault S., Guille M., Darchen F., Lemaitre F., Amatore C. Angew. Chem. Int. Ed. 2011, 50(22), 5081-5084 A microdevice based...
Thumbnail Mertins O., Messina P., Labbé E., Arbault S., Lemaitre F., Buriez O., Amatore C. Inorganica Chimica Acta 2011, 374(1), 59-68 Transport, reactivity and interactions of anti-tumor ferrocene-based...
Thumbnail Loget G., Lapeyre V., Garrigue P., Warakulwit C., Limtrakul J., Delville M.-H., Kuhn A. Chem.Mater.2011, 23, 2595-2599 A bulk procedure based on bipolar electrochemistry is proposed for the...
Thumbnail Bouffier L., Yiu H. H. P., Rosseinsky M. J.Langmuir 2011, 27, 6185-6192. Spherical magnetite nanoparticles (MNPs, 24 nm in diameter) were sequentially functionalized with...
Thumbnail Lenz J., Trieu V., Hempelmann R., Kuhn A. Electroanalysis2011, 23, 1186-1192. We report two methods to prepare ordered macroporous ruthenium oxide electrodes based on a template approach and their...
Thumbnail Scullion L., Doneux T., Bouffier L., Fernig D. G., Higgins S. J., Bethell D., Nichols R. J.J. Phys. Chem. C2011, 115, 8361-8368.Because electron transfer is often highly sensitive to bridge...
Thumbnail Loget G., Kuhn A.Anal. Bioanal. Chem.2011, 400, 1691-1704.Bipolar electrochemistry is a technique with a rather young history in the field of analytical chemistry. Being based on the...
Thumbnail Suraniti E., Studer V., Sojic N., Mano N.Anal. Chem.2011, 83, 2824–2828 Immobilization and electrical wiring of enzymes is of particular importance for the elaboration of efficient biosensors...
Thumbnail Amatore C., Arbault S., Guille M., Lemaitre F.Actualité Chimique 2011, 348-349, 25-31 La production de radicaux libres par les êtres vivants aérobiques a certainement une très mauvaise presse,...
Thumbnail Fattah Z., Loget G., Lapeyre V., Garrigue P., Warakulwit C., Limtrakul J., Bouffier L., Kuhn A. Electrochimica Acta2011, 56, 10562-10566. Autonomous microswimmers are of enormous interest not...
Thumbnail Urbanova V., Li Y., Vytras K., Yvert B., Kuhn A.J. Electroanal. Chem. 2011, 656(1-2), 91-95. In order to understand the dynamics of large neuronal networks, one of the challenges of nowadays...
Thumbnail Reculusa S., Heim M., Gao F., Mano N., Ravaine S., Kuhn A. Adv. Funct. Mater., 2011, 21, 691-698. Porous gold structures with a well-defined pore size and thickness are obtained through...
Thumbnail Qu F., Nasraoui R., Etienne M., Bon Saint-Côme Y., Kuhn A., Lenz J., Gajdzik J., Hempelmann R., Walcarius A.Electrochem. Comm.2011, 13, 138-142.Electro-assisted generation of ultra-thin silica films...