We investigate, at a density functional level, the electric characteristics of 18 complexes of cobalt phthalocyanine (CoPc) and cobalt tetraaminephthalocyanine (CoTAPc) adsorbed on graphene functionalized with CO 2 À or CO moieties. Three models of graphene molecules are used, pristine, defect, and vacancy, leading to 12 complexes with CO 2 À functionalized graphene and 6 complexes with functionalized CO graphene. The molecular structures of the optimized complexes feature covalent adsorption CoÀO lengths of ∼1.9À2.1 Å and CÀN lengths of ∼1.4 Å in parallel, perpendicular, and coplanar structures of graphene with phthalocyanine. All these conformations have a direct effect on the electronic characteristics of the complexes. Binding energies calculated for the interaction between functionalized graphene and phthalocyanine show that structures with defects and vacancies have lower energies than pristine graphene. In particular, we found that complexes having a graphene-CO linked to phthalocyanine by an amide bond are of highest stability (by ∼130 kcal/mol) and the formation of complexes with CO 2 À functionalized graphenes takes place preferably when involved with CoTAPc (by ∼20 kcal/mol). Frontier molecular orbitals (HOMO and LUMO) suggest that several of these complexes behave as charge transfer compounds with phthalocyanine as an electron donor and graphene as an electron acceptor, thus these complexes could behave as sensors because of the absorption properties of phthalocyanine in the UVÀvis region. The calculated currentÀvoltage characteristics show that electron transfer is preferably favored in complexes with parallel structure and with pristine graphene CO 2 À functionalization (∼7 μA) when both conjugates, graphene and phthalocyanine, face each other. The latter implies the transfer of charge through a πÀπ setting. However, the presence of defects and vacancies, for this face to face structure, shows lower electron transfer, having G-Def and G-Vac similar values of electron transfer. The conduction is very low for complexes with high stability (usually the coplanar structures) and with charge transfer features, i.e., those in which the HOMO and LUMO are in separated parts of the complex (usually the perpendicular and the coplanar structures). This study shows that cobalt phthalocyanine conducts electrical current toward graphene through a covalently attached CO 2 À to the graphene.

We present a theoretical study using density functional theory at the M05-2X/6-31G(d)/LANL2DZ level of theory of the structural, stability, reactivity, and electrical properties of cobalt phthalocyanine (CoPc) adsorbed on functionalized graphene (G). The functionalization, localized at the center of graphene, is based on epoxide (−O), hydroxyl (−OH), and carboxyl (−COOH) complexes. Three types of graphene molecules are used: pristine, defect (Def), and vacancy (Vac). Binding energies show large stabilities for G–O–CoPc, from ∼−43 to −65 kcal/mol, and for G–OH–CoPc, from ∼−19 to −32 kcal/mol. No adsorption of CoPc occurs on G–COOH. The HOMO–LUMO gap is shorter by ∼0.5 eV for the complexes containing epoxide and hydroxyl (except for G–Vac) than for the functionalized G, thus implying a higher reactivity of the former. All these results together with the nature of the frontier molecular orbitals, which make functionalized G electron acceptor and CoPc electron donor species, explain the charge transfer properties of the complexes. Complexes containing epoxide functionalization present a better conduction of ∼18 μA (at ∼1 V) than those complexes containing hydroxyl functionalization (∼7 μA). These results show that the adsorption of cobalt phthalocyanine on functionalized graphene is feasible; yielding a tunable hybrid material that allows sensing because of the intrinsic electrical properties provided by functionalized G and CoPc.

Utilizing synchrotron small-angle X-ray scattering (SAXS) integrated with a microfluidic device, micellization kinetics of a diblock co-polymer, poly(ethylene glycol)-b-poly(caprolactone) (PEGb-PCL) was measured in situ with millisecond temporal and micrometer spatial resolution. The evolutionary regimes of polymer micellization-nucleation, fusion, and insertion were directly observed. The five-inlet microfluidic device provided steady continuous mixing of the polymer solution and the antisolvent. Solvent replacement was mainly dominated by lateral diffusion across the hydrodynamically focused central layer, whose thickness could be precisely designed and manipulated from mass balance of the partitioning streams. Knowing the micellization kinetics of the polymers is essential for design and optimization of self-assembled polymeric nanostructures. The technique of integrating SAXS with microfluidic devices can be translatable to other systems for a breadth of applications.

The hybrid cluster complex Cd 8 S(SPh) 15 (MeQ)·CH 3 CN (1) (MeQ + = N-methyl-4,4Ј-bipyridinium) was synthesized and characterized structurally by single-crystal X-ray diffraction analysis. The MeQ + ion is coordinated to one of the cadmium atoms of the cluster by the nitrogen atom of its pyridine

We calculate the interactions of oxygen and water with the Ga-face of GaN clusters, which could be used as testbeds for the actual Ga-face on GaN crystals of importance in electronics; however, our additional goal is the analysis of the nanoclusters for several other applications in nanotechnology. Our results show that the local spin plays an important role in these interactions. It is found that the most stable interaction of O2 and the GaN clusters results in the complete dissociation of the O2 molecule to form two Ga–O–Ga bonds, while the most stable interaction between a H2O molecule and the GaN clusters is the complete dissociation of one of the O–H bonds to form a Ga–O–H bond and a Ga–H bond.

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We report a particulate cell delivery platform, toroidal spiral particles (TSPs), for continuous cell activation, expansion, and local sustained release. Biocompatible TSPs, generated by a self-assembly process of polymeric droplet sedimentation in an aqueous solution and subsequent polymer solidification, possess many engineering design flexibilities to manipulate the microenvironment of the cells to control cell proliferation, migration, and release kinetics. These millimeter-size particles with desired mechanical and physicochemical properties may be potentially used for adoptive cellular therapy (ACT) delivery by a minimally invasive procedure to the tumor mass.

We calculate the interactions of two atomic layer deposition (ALD) reactants, trimethylaluminium (TMA) and tetrakis(ethylmethylamino) hafnium (TEMAH) with the hydroxylated Ga-face of GaN clusters when aluminum oxide and hafnium oxide, respectively, are being deposited. The GaN clusters are suitable as testbeds for the actual Ga-face on practical GaN nanocrystals of importance not only in electronics but for several other applications in nanotechnology. We find that TMA spontaneously interacts with hydroxylated GaN; however it does not follow the atomic layer deposition reaction path unless there is an excess in potential energy introduced in the clusters at the beginning of the optimization, for instance, using larger bond lengths of various bonds in the initial structures. TEMAH also does not interact with hydroxylated GaN, unless there is an excess in potential energy. The formation of a Ga-N(CH3)(CH2CH3) bond during the ALD of HfO2 using TEMAH as the reactant without breaking the Hf-N bond could be the key part of the mechanism behind the formation of an interface layer at the HfO2/GaN interface.