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Full-Text Articles in Engineering
Structural Color Change Following Hydration And Dehydration Of Iridescent Mourning Dove, Matthew Shawkey, Liliana D'Alba, Chad Eliason, Jennifer Koop, Li Jia
Structural Color Change Following Hydration And Dehydration Of Iridescent Mourning Dove, Matthew Shawkey, Liliana D'Alba, Chad Eliason, Jennifer Koop, Li Jia
Li Jia
Dynamic changes in integumentary color occur in cases as diverse as the neurologically controlled iridiphores of cephalopod skin and the humidity-responsive cuticles of longhorn beetles. By contrast, feather colors are generally assumed to be relatively static, changing by small amounts only over periods of months. However, this assumption has rarely been tested even though structural colors of feathers are produced by ordered nanostructures that are analogous to those in the aforementioned dynamic systems. Feathers are neither innervated nor vascularized and therefore any color change must be caused by external stimuli. Thus, we here explore how feathers of iridescent mourning doves …
Method Of Transferring Patterned Non-Densely Packed Interfacial Particle Films Onto Substrates, Li Jia, Matthew Ray
Method Of Transferring Patterned Non-Densely Packed Interfacial Particle Films Onto Substrates, Li Jia, Matthew Ray
Li Jia
A process for transferring patterned non-densely packed interfacial particle films onto substrates by providing a substrate, modifying the substrate so that it is non-water wetting, providing an interfacial film of charged particles, applying a surface modifying procedure to said particles, and applying the interfacial particle film to the modified substrate to thereby form a patterned non-densely packed film on the substrate.
Development Of A Colloidal Lithography Method For Patterning Nonplanar Surfaces, Sarang Bhawalkar, Jun Qing, Michael Heiber, Li Jia
Development Of A Colloidal Lithography Method For Patterning Nonplanar Surfaces, Sarang Bhawalkar, Jun Qing, Michael Heiber, Li Jia
Li Jia
A colloidal lithography method has been developed for patterning nonplanar surfaces. Hexagonal noncontiguously packed (HNCP) colloidal particles 127 nm−2.7 μm in diameter were first formed at the air−water interface and then adsorbed onto a substrate coated with a layer of polymer adhesive 17 nm thick. The adhesive layer plays the critical role of securing the order of the particles against the destructive lateral capillary force generated by a thin film of water after the initial transfer of the particles from the air−water interface. The soft lithography method is robust and very simple to carry out. It is applicable to a …
N-Type Conjugated Polymers Containing Diborylene Units, Methods Of Making, And A Device Comprising The Compound, Li Jia
Li Jia
N-type conjugated compounds are disclosed which include at least one conjugated electron-acceptor unit The conjugated electron-acceptor unit includes a diborylene unit The compounds find application in an electron acceptor layer of an electronic device.
Regioregular Poly(3-Alkanoylthiophene): Synthesis And Electrochemical, Photophysical, Charge Transport, And Photovoltaic Properties, Chao Wang, Felix Kim, Guoqiang Ren, Yongqian Xu, Yi Pang, Samson Jenekhe, Li Jia
Regioregular Poly(3-Alkanoylthiophene): Synthesis And Electrochemical, Photophysical, Charge Transport, And Photovoltaic Properties, Chao Wang, Felix Kim, Guoqiang Ren, Yongqian Xu, Yi Pang, Samson Jenekhe, Li Jia
Li Jia
Head-to-tail regioregular poly(3-heptanoylthiophene) (PHOT) was synthesized by Ni-catalyzed polycondensation of the 2,2-dimethyl-1,3-propanediol-protected Grignard monomer followed by deprotection. Cyclic voltammetric (CV) study demonstrates that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of PHOT are 0.5 eV lower in energy than those of the head-to-tail poly(3-hexylthiophene) (HT-P3HT). Their optical band gaps are essentially the same. Incomplete photoluminescence (PL) quenching was observed in thin films of the 1:1 blend of PHOT and HT-P3HT. PHOT displayed a glass transition at ∼269 °C and decomposed at ∼300 °C according to differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Wide-angle X-ray …
Antifouling Poly(B-Peptoid)S, Shaohui Lin, Bo Zhang, Michael Skoumal, Brian Ramunno, Xiaopeng Li, Chrys Wesdemiotis, Lingyun Liu, Li Jia
Antifouling Poly(B-Peptoid)S, Shaohui Lin, Bo Zhang, Michael Skoumal, Brian Ramunno, Xiaopeng Li, Chrys Wesdemiotis, Lingyun Liu, Li Jia
Li Jia
A new type of polymer highly resistant to nonspecific protein adsorption is reported. Poly(N-methyl-β-alanine) (PMeA) and poly(N-ethyl-β-alanine) (PEtA) synthesized via cobalt-catalyzed carbonylative polymerization of N-methylaziridine and N-ethylaziridine were end-functionalized with thiol groups and grafted onto Au surfaces. Protein adsorption was studied by the surface plasmon resonance (SPR) method. The amounts of representative single proteins adsorbed onto the PMeA- and PEtA-grafted surfaces were below the detection limit of SPR at the pg/mm(2) level. After exposure to full blood plasma and serum for 10 min, protein adsorption was at the level of ∼ 100 pg/mm(2), similar to the level of protein adsorption …
Synthesis And Electrochemical Properties Of A New Class Of Boron-Containing N-Type Conjugated Polymers, Jianfang Chai, Chao Wang, Li Jia, Yi Pang, Matthew Graham, Stephen Cheng
Synthesis And Electrochemical Properties Of A New Class Of Boron-Containing N-Type Conjugated Polymers, Jianfang Chai, Chao Wang, Li Jia, Yi Pang, Matthew Graham, Stephen Cheng
Li Jia
Several electron-deficient polymers containing the 9,10-diboroanthracene unit have been synthesized and characterized. Electrochemical study shows that they have high electron affinities. Photoluminescence of rr-P3HT is quenched in the presence of one of the polymers in the solid state, demonstrating the potential utility of this class of polymer as powerful n-type materials in organic photovoltaic devices.
Cobalt-Catalyzed Carbonylative Polymerization Of Azetidines, Jianfang Chai, Guosheng Liu, Kittisak Chaicharoen, Chrys Wesdemiotis, Li Jia
Cobalt-Catalyzed Carbonylative Polymerization Of Azetidines, Jianfang Chai, Guosheng Liu, Kittisak Chaicharoen, Chrys Wesdemiotis, Li Jia
Li Jia
We provide a full account on our study of the cobalt-catalyzed carbonylative polymerization of N-alkylazetidines involving three representative monomers. The individual N-alkylazetidine monomers display different characteristics in the polymerization, allowing the incorporation of amine and ester units into the amide-based polymers. We will first present the synthesis and characterization of poly(amide-co-amine) with a gradient amine distribution. Then, we will describe how to control the ester distribution in poly(amide-co-ester)s. Poly(amide-co-ester)s containing multiple segments, within which the ester units distribute in a gradient fashion, will be compared with multiblock poly(amide-co-ester)s. Finally, we report our discovery of a novel chain transfer pathway via …
Novel Use Of Polymer Brush In Colloidal Lithography To Overcome Lateral Capillary Force, Jun Qian, Sarang Bhawalkar, Yongshen Xu, Li Jia
Novel Use Of Polymer Brush In Colloidal Lithography To Overcome Lateral Capillary Force, Jun Qian, Sarang Bhawalkar, Yongshen Xu, Li Jia
Li Jia
A general method has been developed for transferring interfacially trapped, submonolayer hexagonal arrays of silica particles for nano- and mesoscopic surface patterning. Poly(n-butyl acrylate) and poly(n-butyl acrylate-random-N,N-diethylaminoethyl acrylate) brushes were grafted on the substrates via the "graft-from" method using atom transfer radical polymerization. The polymer brush served as an adhesive promoter between the particles and the substrate and proved to be effective for locking the particles in the hexagonal lattice against the lateral capillary force arising from a thin layer of water attached to the surface of the substrate. Several parameters that influence preservation of the order of the particle …
Synthesis Of Oligo-B-Alanine-Based Surfactant Via Cobalt-Catalyzed Carbonylation And Surface Activity Study, Li Jia, Stephen Moylan, Yi-Lang Liang, Eric Daniels, Andrew Klein
Synthesis Of Oligo-B-Alanine-Based Surfactant Via Cobalt-Catalyzed Carbonylation And Surface Activity Study, Li Jia, Stephen Moylan, Yi-Lang Liang, Eric Daniels, Andrew Klein
Li Jia
Synthesis of a novel surfactant with an oligo-β -alanine hydrophilic headgroup was achieved via the carbonylative oligomerization of aziridine followed by coupling with n-octylamine in one pot. The chemical structure of the surfactant was confirmed by NMR and MALDI MS. Preliminary studies on its surface properties, including surface tension measurement and its adsorption on polystyrene latex particles, are reported.
Poly(Beta-Alanoid-Block-Beta-Alanine)S: Synthesis Via Cobalt-Catalyzed Carbonylative Polymerization And Self-Assembly, Shaohui Lin, Xinfei Yu, Yingfeng Tu, Hongyu Xu, Stephen Cheng, Li Jia
Poly(Beta-Alanoid-Block-Beta-Alanine)S: Synthesis Via Cobalt-Catalyzed Carbonylative Polymerization And Self-Assembly, Shaohui Lin, Xinfei Yu, Yingfeng Tu, Hongyu Xu, Stephen Cheng, Li Jia
Li Jia
The titled diblock copolymers are synthesized via cobalt-catalyzed living carbonylative polymerization of N-alkylaziridines under moderate pressures followed by a deprotection step. The poly(beta-alanine) block is solubilized by the poly(beta-alanoid) block in chloroform and remains fully hydrogen-bonded in the form of a sheet-like assembly.