Microporous capsules (MCs) such as polymerosomes [1,2] feature attractive properties for potential applications in materials development, optics, electronics, and delivery. [3,4] Colloidosomes are a related class of MCs whose shells consists of densely packed colloidal particles. These systems feature useful attributes including enhanced mechanical stability and controlled pore-size distribution, [5] as well as the optical, fluorescent, and magnetic properties of their precursor particles.Colloidosomes feature an identical solvent inside and out (typically water), and have been generally synthesized using micrometer-or submicrometer-sized particles. [4a,6] However, the formation of stable colloidosomes using nanoparticles (NPs) <20 nm in diameter remains a challenge. [7] The competition between the interfacial energy and the spatial fluctuation of the NPs resulting from thermal energy causes instability of the emulsions. Recent approaches to fabricate colloidosomes have included different types of NPs, as well as the use of assembly strategies. [8,9] For example, Duan et al. have used agarose to gelate water at the water-oil interface and transferred the resultant MCs into water to create stable colloidosomes. [9] In recent studies, we and others have developed various crosslinking reactions between NPs at water-oil droplet interfaces. [10] However, to the best of our knowledge there are no reports of successful transfer of these crosslinked droplets into water to synthesize colloidosomes.Herein, we report the fabrication of stable magnetic colloidosomes by crosslinking NPs at a water-oil interface using click chemistry under ambient conditions. In this strategy, alkyne-and azide-functionalized Fe 3 O 4 NPs were coassembled at the interface and covalently linked using a Cu(I)-catalyzed Huisgen click reaction. [11,12] There are two major advantages for this interfacial crosslinking method. First, click chemistry involving alkyne and azide functional groups is highly selective and essentially inert to the many functional groups and environmental conditions (e.g., pH and solvent). [13][14][15][16][17] Second, this methodology provides dense packing of NPs on the colloidosome shell, resulting in high stability of the colloidosomes.The alkyne (IO-1) and azide (IO-2) NPs used in this study were formed by place-exchange of oleic acid from Fe 3 O 4 NPs that were 11.3 AE 2 nm in diameter (see Supporting Information, Figure S1). These NPs were dissolved in an equimolar ratio in oil (a mixture of toluene and methylene chloride with a 7:1 ratio), and an aqueous solution of the Cu(I) catalyst (a mixture of CuSO 4 and sodium L-ascorbate) was added with vigorous shaking for %30 s (Scheme 1). The colloidosomes formed by this technique were 49 AE 15 mm (Figure 1a) in diameter, and required a crosslinking time of 30 min with a catalyst concentration of 0.8 mM to form stable assemblies. The catalyst concentration had little effect on the shape and size of the colloidosomes (see Supporting Information, Figure S2), however onl...

Segment block dendrimers consisting of polyester and polyaryl ether dendrons were synthesized using reagent free Diels-Alder cycloaddition reactions. Three generations of furan functionalized polyaryl ether dendrons were reacted with maleimide functionalized polyester dendrons of the same generation to obtain segment block dendrimers in good yields. The thermoreversible nature of these macromolecules was investigated by subjecting them to elevated temperatures in the presence of anthracene as a scavenger diene.

The fabrication of polymeric thin fi lms amenable to facile functionalization by reactive μ CP via a Diels-Alder reaction is described. Precursor copolymers containing FuMA, PEGMA, and TMSMA are prepared using ATRP. Surface-tethered thin fi lms of these polymers are obtained on oxidized silicon and glass substrates and patterned with maleimide-appended dye molecules by simple μ CP to demonstrate effi cient functionalization via Diels-Alder reaction. Printing of biotin-based ligands is carried out to demonstrate directed immobilization of the enzyme streptavidin. Due to the thermoreversible nature of the Diels-Alder reaction, these surfaces can be used as rewritable platforms. This is demonstrated by sequential write-erase-rewrite protocols via μ CP of a maleimide-containing fl uorescent dye.reactions have been utilized to date toward effi cient functionalization of appropriately modifi ed solid substrates. The Cu-catalyzed Huisgen [3 + 2] reaction is perhaps the most utilized one, but other "click" reactions such as the thiol-ene and Diels-Alder reactions are drawing attention due to their metal-free nature. Among the later reactions, the Diels-Alder reaction provides an attractive alternative due to the following attributes: (1) appropriate choice of diene and dienophile provides products in good yields in a highly predictable manner, (2) the reaction could be conducted in aqueous medium or neat without harsh chemical conditions, (3) most often no additional reagents or catalysts are required, and (4) reaction is thermoreversible. [ 3 ] As mentioned in the last point, this conjugationdeconjugation reaction harbors several reaction systems which could be irreversible or reversible over different temperature ranges based upon the molecular structure of the diene-dienophile pair. [ 4 ] Specifi cally, the maleimidefuran-based systems have attracted immense attention because of the "self-healing" feature that allows the fabrication of remendable materials. [ 5 ] To date, most of the efforts in the area of surface functionalization using the Diels-Alder reaction have focused on the modifi cation of self-assembled monolayers on

Asymmetric reduction of ketimines with trichlorosilane can be catalysed by the Lewis-basic N-methylvaline-derived formamide anchored to a soluble dendron () with good enantioselectivity (

Diaminopyridine dendritic scaffolds encapsulate polymeric flavin via non-covalent interactions and demonstrate isolation of the redox moiety.Scheme 1 Alkyne-functionalized flavin 1, control N-methylated flavin 2, flavin polymer 3 exhibit specific three-point hydrogen bonding interactions with complementary dendrons, control polymer 4, and a schematic representation of encapsulation of flavin polymer.