A Tetraphenylethene Luminogen-Functionalized Gemini Surfactant for Simple and Controllable Fabrication of Hollow Mesoporous Silica Nanorods with Enhanced Fluorescence.

Nanoparticles that possess unique structures and properties are highly desired in the production of multifunctional materials because of their combinational performance. In this study, a facile and effective fabricating strategy is developed to controllably prepare fluorescent hollow mesoporous silica nanorods via the cetyltrimethylammonium bromide (CTAB) and tetraphenylethene (TPE) luminogen-functionalized gemini surfactant (CTPE-C6-CTPE) guided dual-templating approach. Because of its unique chemical structure, water solubility, surface activity, and fluorescent properties, the designed CTPE-C6-CTPE will not only provide an anchored fluorophore for silica nanoparticles but also serve as an intimate partner of CTAB to regulate their construction in the structure-directing process. By properly tuning the molar ratio of CTAB/CTPE-C6-CTPE, the shape-controlled aggregation-induced emission hollow mesoporous silica nanoparticles (AIE-MSNs) can be prepared directly, producing two kinds of silica nanorods (AIE-MSNs-15 and AIE-MSNs-7). In particular, the incorporated bulky TPE luminogens will not only endow AIE-MSNs-7 with enhanced fluorescence intensity (2.3-fold) after the removal of CTAB but also bring about high accessible surface area (606.6 m2/g) and larger pore size (3.2 nm) and pore volume (0.634 cm3/g) for effective loading and sustained release of the hydrophobic anticancer drug camptothecin. CTPE-C6-CTPE enriches the family of gemini surfactants and provides important insights into the convenient fabrication of advanced fluorescent mesoporous materials.

Rational Design and Synthesis of Carboxylate Gemini Surfactants with an Excellent Aggregate Behavior for Nano-La2O3 Morphology-Controllable Preparation.

A series of carboxylate gemini surfactants (CGS, Cn-Φ-Cn, n = 12, 14, 16, 18) with diphenyl ketone as a spacer group were prepared using a simple and feasible synthetic method. These CGS exhibited an excellent surface activity with extremely low critical micelle concentration (CMC) value (approximately 10-5 mol/L), good performance in reducing surface tension (nearly 30 mN/m), and the ability of molecular self-assembly into different aggregate morphologies via adjusting the concentrations, which is attributed to the introduction of diphenyl ketone and carboxylic acid ammonium salt in the molecular structure. Moreover, the surface activity and self-assembly ability of CGS were further optimized by tuning the length of the tail chain. These excellent properties imply that CGS can be a soft template to prepare nanomaterials, especially in morphology-controllable synthesis. By adjusting the concentration of one of CGS (C12-Φ-C12), nano-La2O3 particles with diverse morphologies were obtained, including spherical shape, bead-chain shape, rod shape, velvet-antler shape, cedar shape, and bowknot shape. This work offers a vital insight into the rational design of template agents for the development of morphology-controllable nanomaterials.

Triple Acceptors in a Polymeric Architecture for Balanced Ambipolar Transistors and High-Gain Inverters.

The exploration of novel molecular architectures is crucial for the design of high-performance ambipolar polymer semiconductors. Here, a "triple-acceptors architecture" strategy to design the ambipolar polymer DPP-2T-DPP-TBT is introduced. The utilization of this architecture enables DPP-2T-DPP-TBT to achieve deep-lying highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) levels of -5.38/-4.19 eV, and strong intermolecular interactions, which are favorable for hole/electron injection and intermolecular hopping through π-stacking. All these factors result in excellent ambipolar transport characteristics and promising applications in complementary-like circuits for DPP-2T-DPP-TBT under ambient conditions with high hole/electron mobilities and a gain value of up to 3.01/3.84 cm2 V-1 s-1 and 171, respectively, which are among the best performances in ambipolar polymer organic thin-film transistors and associated complementary-like circuits, especially in top-gate device configuration with low-cost glass as substrates. These results demonstrate that the "triple-acceptors architecture" strategy is an effective way for designing high-performance ambipolar polymer semiconductors.

Spectrofluorimetric study of the interaction of copper(II) and bis-heterocyclictriazene reagent in the presence of beta-cyclodextrin.

A new reagent, 1,3-bis(2-benzothiazolyl-diazoamino)benzene (BBTAB), was first synthesized and characterized by elemental analysis, 1H NMR and IR spectra. The inclusion complex of BBTAB with beta-cyclodextrin (beta-CD) was formed. BBTAB in the inclusion complex or alone reacts with copper(II) to form chelate complex in a slight basic medium, which results in drastic or slight fluorescence enhancement, respectively. The spectrofluorimetric method of trace amount of copper(II) based on the enhancement of inclusion complex by binding with copper(II) was established. The excitation and emission wavelengths of the BBTAB/beta-CD/Cu system are 389 and 480 nm, respectively. Under optimal conditions, a linear response of BBTAB/beta-CD to copper(II) is obtained in the range of 3.0 x 10(-7) to 1.0 x 10(-5) mol L(-1), and the detection limit is determined to be 1.2 x10(-8) mol L(-1). The method is selective, sensitive and simple, and has been used for the determination of trace copper(II) in water samples with satisfactory results. The possible response mechanism of BBTAB/beta-CD or BBTAB to copper(II) and the role of beta-CD in the drastic enhancement of fluorescence of BBTAB/beta-CD/Cu system have been discussed.