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1.
Adv Mater ; : e2104747, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34558121

RESUMO

In order to apply polymer semiconductors to stretchable electronics, they need to be easily deformed under strain without being damaged. A small number of conjugated polymers, typically with semicrystalline packing structures, have been reported to exhibit mechanical stretchability. Herein, a method is reported to modify polymer semiconductor packing-structure using a molecular additive, dioctyl phthalate (DOP), which is found to act as a molecular spacer, to be inserted between the amorphous chain networks and disrupt the crystalline packing. As a result, large-crystal growth is suppressed while short-range aggregations of conjugated polymers are promoted, which leads to an improved mechanical stretchability without affecting charge-carrier transport. Due to the reduced conjugated polymer intermolecular interactions, strain-induced chain alignment and crystallization are observed. By adding DOP to a well-known conjugated polymer, poly[2,5-bis(4-decyltetradecyl)pyrrolo[3,4-c]pyrrole-1,4-(2H,5H)-dione-(E)-1,2-di(2,2'-bithiophen-5-yl)ethene] (DPPTVT), stretchable transistors are obtained with anisotropic charge-carrier mobilities under strain, and stable current output under strain up to 100%.

2.
Bioresour Technol ; 342: 125935, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34571329

RESUMO

At present, sustainable and stable partial nitrification has not been widely achieved in the mainstream PN/ANAMMOX process. Here, the feasibility of sustainable and stable partial nitrification was demonstrated in automatic recycling PN/ANAMMOX reactor under mainstream conditions using both simulation and experimental methods. Stable nitrite accumulation in the aerobic zone could be achieved via regulating dissolved oxygen (DO) concentrations and sludge retention time (SRT). The DO concentrations required for the repression of nitrite-oxidizing bacteria (NOB) were lower at longer SRTs. The DO concentrations and SRTs required for NOB repression were lower at lower temperatures. However, NOB repression was diminished by a persistent low DO and short SRT under mainstream conditions. With the introduction of automatic recycling, sustainable and stable partial nitrification was achieved. Effluent recycling could limit the nitrite-nitrogen required for NOB growth. Collectively, effluent recycling may serve as a feasible and useful strategy for NOB inhibition during the PN/ANAMMOX process.

3.
Nat Commun ; 12(1): 4880, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385444

RESUMO

Accurate and imperceptible monitoring of electrophysiological signals is of primary importance for wearable healthcare. Stiff and bulky pregelled electrodes are now commonly used in clinical diagnosis, causing severe discomfort to users for long-time using as well as artifact signals in motion. Here, we report a ~100 nm ultra-thin dry epidermal electrode that is able to conformably adhere to skin and accurately measure electrophysiological signals. It showed low sheet resistance (~24 Ω/sq, 4142 S/cm), high transparency, and mechano-electrical stability. The enhanced optoelectronic performance was due to the synergistic effect between graphene and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which induced a high degree of molecular ordering on PEDOT and charge transfer on graphene by strong π-π interaction. Together with ultra-thin nature, this dry epidermal electrode is able to accurately monitor electrophysiological signals such as facial skin and brain activity with low-motion artifact, enabling human-machine interfacing and long-time mental/physical health monitoring.


Assuntos
Eletrodos , Eletrofisiologia/métodos , Epiderme/fisiologia , Desenho de Equipamento/métodos , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Artefatos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Condutividade Elétrica , Eletrofisiologia/instrumentação , Eletrofisiologia/normas , Desenho de Equipamento/normas , Grafite/química , Humanos , Estrutura Molecular , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/normas , Movimento (Física) , Polímeros/química , Poliestirenos/química , Pele
4.
Artigo em Inglês | MEDLINE | ID: mdl-34006092

RESUMO

Semiconducting polymers are at the forefront of next-generation organic electronics due to their robust mechanical and optoelectronic properties. However, their extended π-conjugation often leads to materials with low solubilities in common organic solvents, thus requiring processing in high-boiling-point and toxic halogenated solvents to generate thin-film devices. To address this environmental concern, a natural product-inspired side-chain engineering approach was used to incorporate galactose-containing moieties into semiconducting polymers toward improved processability in greener solvents. Novel isoindigo-based polymers with different ratios of galactose-containing side chains were synthesized to improve the solubilities of the organic semiconductors in alcohol-based solvents. The addition of carbohydrate-containing side chains to π-conjugated polymers was found to considerably impact the intermolecular aggregation of the materials and their microstructures in the solid state as confirmed by atomic force microscopy and grazing-incidence wide-angle X-ray scattering. The charge transport characteristics of the new semiconductors were evaluated by the fabrication of organic field-effect transistors prepared from both toxic halogenated and greener alcohol-based solvents. Importantly, the incorporation of carbohydrate-containing side chains was shown to have very little detrimental impact on the electronic properties of the polymer when processed from green solvents.

5.
Nano Lett ; 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34037405

RESUMO

Solid-electrolyte interphase (SEI) plays a pivotal role in stabilizing lithium (Li) metal anode for rechargeable batteries. However, electrolyte-derived SEI often suffers from poor stability, leading to Li dendrite growth, consumption of electrolyte, and short cycle life. Here, we report a porous lithiophilic polymer coating induced by phase separation of polyvinylidenefluoride-polyacrylonitrile (PVDF-PAN) blends for stabilizing Li metal anode. Different from single polymer coating, PVDF-PAN blends protective layer with porous structures caused by phase separation can provide effective Li+ transport channels and regulate uniform Li+ flux. The lithiophilic functional groups of C≡N and C-F can promote uniform Li deposition and accelerate Li+ diffusion at the same time during plating/stripping process. As a result, Li||NCM811 full cells using PVDF-PAN coated Li present an apparently improved cycling stability and higher Coulombic efficiency with lean electrolyte (7.5 µL mA h-1), limited Li supply (N/P ratio = 2.4), and high areal capacity (4.0 mA h cm-2).

6.
Adv Ther ; 38(5): 2315-2322, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33740216

RESUMO

INTRODUCTION: To evaluate the efficacy and safety of sublingual immunotherapy (SLIT) with standardized Dermatophagoides farinae (Df) drops in monosensitized and polysensitized patients with allergic rhinitis (AR) and to analyze the adverse events (AEs). METHODS: A retrospective analysis was performed using data for 68 patients with AR who received SLIT. The patients were divided into a monosensitized group (36 cases) and a polysensitized group (32 cases) based on serum-specific IgE test results. In the two groups of patients, total nasal symptoms score (TNSS), total medication score (TMS), visual analog scale (VAS) score, and AEs before treatment and at 1, 3, 6, and 12 months of treatment were evaluated. RESULTS: Compared with that before treatment, the TNSS, TMS, and VAS score in the monosensitized and polysensitized groups all decreased significantly at 3, 6, and 12 months of SLIT (all P < 0.05). There were no significant differences in treatment efficacy indicators between the two groups at all treatment time points (all P > 0.05). In terms of safety, compared with 1 month after initiating SLIT, the incidence of AEs in the monosensitized and polysensitized groups at 6 and 12 months of treatment significantly decreased (all P < 0.05). There was a statistically significant decrease in the incidence of AEs in both groups at 6 months compared with 3 months of treatment (χ2 = 1.92 and 5.85, respectively, all P < 0.05). The difference in incidence of AEs between the monosensitized and polysensitized groups was not statistically significant at any treatment time point (all P > 0.05). AEs in all patients were local mild reactions; no serious AEs were found. CONCLUSION: SLIT with standardized Df drops has similar efficacy and safety for monosensitized and polysensitized patients with AR. AEs mostly occurred during the first 3 months of SLIT in both the monosensitized and polysensitized groups, and the incidence of AEs gradually decreased as the course of treatment extended.


Assuntos
Rinite Alérgica , Imunoterapia Sublingual , Animais , Antígenos de Dermatophagoides , Dermatophagoides farinae , Humanos , Estudos Retrospectivos , Rinite Alérgica/terapia , Resultado do Tratamento
7.
PLoS One ; 16(2): e0247248, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33600459

RESUMO

The conversion of cellular prion protein (PrPC) to disease-provoking conformer (PrPSc) is crucial in the pathogenesis of prion diseases. Heparin has been shown to enhance mammalian prion protein misfolding. As spontaneous prion disease has not been reported in non-mammalian species, such as chicken, it is interesting to explore the influence of heparin on the conversion of chicken prion protein (ChPrP). Herein, we investigated the influences of heparin on biochemical properties of full-length recombinant ChPrP, with murine prion protein (MoPrP) as control. The results showed that at low heparin concentration (10 µg/mL), a great loss of solubility was observed for both MoPrP and ChPrP using solubility assays. In contrast, when the concentration of heparin was high (30 µg/mL), the solubility of MoPrP and ChPrP both decreased slightly. Using circular dichroism, PK digestion and transmission electron microscopy, significantly increased ß-sheet content, PK resistance and size of aggregates were observed for MoPrP interacted with 30 µg/mL heparin, whereas 30 µg/mL heparin-treated ChPrP showed less PK resistance and slight increase of ß-sheet structure. Therefore, heparin can induce conformational changes in both MoPrP and ChPrP and the biochemical properties of the aggregates induced by heparin could be modified by heparin concentration. These results highlight the importance of concentration of cofactors affecting PrP misfolding.


Assuntos
Endopeptidase K/metabolismo , Heparina/farmacologia , Proteínas Priônicas/química , Proteínas Priônicas/genética , Animais , Galinhas , Dicroísmo Circular , Camundongos , Microscopia Eletrônica de Transmissão , Modelos Moleculares , Proteínas Priônicas/metabolismo , Conformação Proteica , Conformação Proteica em Folha beta , Proteólise , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Solubilidade
8.
Angew Chem Int Ed Engl ; 60(15): 8189-8197, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33403799

RESUMO

Doping of polymeric semiconductors limits the miscibility between polymers and dopants. Although significant efforts have been devoted to enhancing miscibility through chemical modification, the electrical conductivities of n-doped polymeric semiconductors are usually below 10 S cm-1 . We report a different approach to overcome the miscibility issue by modulating the solution-state aggregates of conjugated polymers. We found that the solution-state aggregates of conjugated polymers not only changed with solvent and temperature but also changed with solution aging time. Modulating the solution-state polymer aggregates can directly influence their solid-state microstructures and miscibility with dopants. As a result, both high doping efficiency and high charge-carrier mobility were simultaneously obtained. The n-doped electrical conductivity of P(PzDPP-CT2) can be tuned up to 32.1 S cm-1 . This method can also be used to improve the doping efficiency of other polymer systems (e.g. N2200) with different aggregation tendencies and behaviors.

9.
Sensors (Basel) ; 20(16)2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32824509

RESUMO

Wi-Fi network has an open nature so that it needs to face greater security risks compared to wired network. The MAC address represents the unique identifier of the device, and is easily obtained by an attacker. Therefore MAC address randomization is proposed to protect the privacy of devices in a Wi-Fi network. However, implicit identifiers are used by attackers to identify user's device, which can cause the leakage of user's privacy. We propose device identification based on 802.11ac probe request frames. Here, a detailed analysis on the effectiveness of 802.11ac fields is given and a novel device identification method based on deep learning whose average f1-score exceeds 99% is presented. With a purpose of preventing attackers from obtaining relevant information by the device identification method above, we design a novel defense mechanism based on stream cipher. In that case, the original content of probe request frame is hidden by encrypting probe request frames and construction of probe request is reserved to avoid the finding of attackers. This defense mechanism can effectively reduce the performance of the proposed device identification method whose average f1-score is below 30%. In general, our research on attack and defense mechanism can preserve device privacy better.

10.
J Environ Manage ; 270: 110887, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721325

RESUMO

The long-term effect of nitrate recycling ratios (R = 100%-500%) on the denitrifying phosphorus removal (DPR) characteristics was studied in a novel two-sludge system, which coupled Anaerobic Anoxic Oxic (A2/O) with Moving Bed Biofilm Reactor (MBBR) for simultaneous nitrogen (N) and phosphorus (P) removals. During the 220 days' operation, effluent COD (30.87-45.15 mg/L) can meet the discharge standard completely, but N and P removals were significantly affected by the R-value, including CODintra removal efficiency (CODintra-Re: 56.09-85.98%), TN removal (TN-Re: 52.06-80.50%), anaerobic PO43- release (PO43--An: 10.66-29.02 mg/L) and oxic PO43- absorption (PO43--O: 2.22-6.26 mg/L). Meanwhile, N and P displayed close correlation with the ΔPO43-/ΔNO3- ratio of 4.20-4.41 at R = 300%-400%, resulting in the high-efficient anoxic poly-ß-hydroxyalkanoates (PHA) utilization (ΔPHAA: 64.88 mgCOD/gVSS). Based on the stoichiometry methodology, at R of 300%-400%, the percentages of phosphorus accumulation organisms (PAOs) and glycogen accumulating organisms (GAOs) contributed to ΔPHAAn (ΔGlyAn) were 71.7%, 28.3% (61.3%, 38.7%) in the anaerobic stage, respectively, while N denitrification rate (NDRA: 3.91-3.93 mg N/(gVSS·h)) and P uptake rate (PURA: 3.76-3.90 mg P/(gVSS·h)) reached the peak, suggesting superior DPR performance with higher contribution of denitrifying PAOs (DPAOs) (70%) than denitrifying GAOs (DGAOs) (30%) in the anoxic stage. Microbial community analysis showed that Accumulibacter (27.66-30.01%) was more enriched than Competibacter (13.41-14.34%) and was responsible for the improved C, N, P removals and DPR characteristics. For optimizing operation, the combined effect of nitrate recycling ratio with other process parameters especially economic evaluation should be considered.


Assuntos
Fósforo , Águas Residuárias , Biofilmes , Reatores Biológicos , Desnitrificação , Nitrogênio , Nutrientes , Esgotos , Eliminação de Resíduos Líquidos
11.
J Environ Manage ; 262: 110391, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250835

RESUMO

Granule formation has been recognized as a promising biotechnology in denitrifying phosphorus removal (DPR) systems by facilitating phosphorus accumulation organisms (PAOs) especially denitrifying PAOs (DPAOs), and hydraulic selection made this a more difficult task in continuous operation. This study aimed at exploring the microscopic mechanism and putting forward an effective strategy for DPR granulation under the impact of hydraulic retention time (HRT) (12 h, 10 h, 8 h) in a novel Anaerobic Anoxic Oxic - Moving Bed Biofilm Reactor (A2/O - MBBR) system. With the reduction of intracellular carbon storage (CODintra) efficiency (88.58%-78.53%), nitrogen (N) (85.45%-79.11%) and phosphorus (P) (96.55%-92.47%) removals both dropped, but it exhibited a growth of anoxic phosphorus uptake rate (PURA) (3.79-5.68 mg P/(gMLVSS·h)). The batch tests associating with substrate transformation of poly-ß-hydroxyalkanoates (PHA), glycogen (Gly) agreed well with the corresponding stoichiometry of phosphorus release rate (PRR) (4.83-7.53 mg P/(gMLVSS·h)), PURA (3.55-5.43 mg P/(gMLVSS·h)), oxic phosphorus uptake rate (PURO) (6.08-6.21 mg P/(gMLVSS·h)), and DPAOs/PAOs ratios (57.17%-89.31%), indicating a shift of microbial community. DPR granules gradually stabilized with low sludge volume index (SVI5/SVI30 ratio = 1.1-1.2), dense and compact structure, higher P content (11.63%), more extracted extracellular polymeric substances (EPS) (111.40-160.31 mg/gMLVSS) as proteins/polysaccharides (PN/PS) ratios (1.70-3.47) increased, leading to better sludge settleability and cell hydrophobicity. Fluorescence in situ hybridization (FISH) results showed that PAOs (mainly Cluster I: 20.20%) were the dominant bacteria in the A2/O reactor although a small amount of Defluviicoccus (3.18-3.48%) was responsible for nitrite accumulation, while ammonium-oxidizing bacteria (AOB) (mainly Nitrosomonas: 10.75%) and nitrite-oxidizing bacteria (NOB) (mainly Nitrospira: 15.06%) were enriched in the MBBR.


Assuntos
Fósforo , Esgotos , Biofilmes , Reatores Biológicos , Hibridização in Situ Fluorescente , Nitrogênio , Eliminação de Resíduos Líquidos
12.
ACS Appl Mater Interfaces ; 12(14): 16531-16540, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32192336

RESUMO

Nonfullerene acceptors (NFAs) have contributed significantly to the progress of organic solar cells (OSCs). However, most NFAs feature a large fused-ring backbone, which usually requires a tedious multiple-step synthesis, and are not applicable to commercial applications. An alternative strategy is to develop nonfused NFAs, which possess synthetic simplicity and facile tunability in optoelectronic properties and solid-state microstructures. In this work, we report two nonfused NFAs, BTCIC and BTCIC-4Cl, based on an A-D-A'-D-A architecture, which possess the same electron-deficient benzothiadiazole central core but different electron-withdrawing terminal groups. The optical properties, energy levels, and molecular crystallinities were finely tuned by changing the terminal groups. Moreover, a decent power conversion efficiency of 9.3 and 10.5% has been achieved by BTCIC and BTCIC-4Cl, respectively, by blending them with an appropriate polymer donor. These results demonstrate the potential of A-D-A'-D-A type nonfused NFAs for high-performance OSCs. Further development of nonfused NFAs will be very fruitful by employing appropriate building blocks and via side-chain optimizations.

13.
Allergy Rhinol (Providence) ; 11: 2152656720902142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32201632

RESUMO

Purpose: To investigate the effect of biospray dressing on the extent of eosinophil infiltration in the nasal mucosa and the level of serum IgE in experimental allergic rhinitis with nasal provocation. Method: Twenty-four BALB/c mice were randomly divided into the normal control group, allergic rhinitis (AR) group, dexamethasone (DEX) treatment group, and biospray dressing (BD) group. The mice in the latter 3 groups were prepared for animal models of AR according to standard protocols. Mice in the BD group were administered a nasal spray before the nasal provocation, and those in the DEX group were administered an intraperitoneal injection of DEX. The nasal mucosa and serum were collected from each group. Nasal mucosa eosinophil infiltration was evaluated using hematoxylin and eosin staining, and enzyme-linked immunosorbent assay (ELISA) was performed to analyze the serum IgE expression. Results: Eosinophil infiltration (AR vs BD P = .009) in the nasal mucosa and serum IgE expression (AR vs BD P = .001) were significantly lower in the BD group than in the AR group. There were no significant differences in the extent of eosinophil infiltration in the nasal mucosa or serum IgE expression between the BD and DEX groups. Conclusion: Biospray dressings can significantly reduce allergen provocation in the nasal cavity and have a protective effect on the nasal mucosa. They can be used for the prevention and treatment of AR.

14.
J Am Chem Soc ; 141(51): 20215-20221, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31774667

RESUMO

n-Doped conjugated polymers usually show low electrical conductivities and low thermoelectric power factors, limiting their applications in n-type organic thermoelectrics. Here, we report the synthesis of a new diketopyrrolopyrrole (DPP) derivative, pyrazine-flanked DPP (PzDPP), with the deepest LUMO level in all the reported DPP derivatives. Based on PzDPP, a donor-acceptor copolymer, P(PzDPP-CT2), is synthesized. The polymer displays a deep LUMO energy level and strong interchain interaction with a short π-π stacking distance of 3.38 Å. When doped with n-dopant N-DMBI, P(PzDPP-CT2) exhibits high n-type electrical conductivities of up to 8.4 S cm-1 and power factors of up to 57.3 µW m-1 K-2. These values are much higher than previously reported n-doped DPP polymers, and the power factor also ranks the highest in solution-processable n-doped conjugated polymers. These results suggest that PzDPP is a promising high-performance building block for n-type organic thermoelectrics and also highlight that, without sacrificing polymer interchain interactions, efficient n-doping can be realized in conjugated polymers with careful molecular engineering.

15.
Sci Adv ; 5(11): eaav3097, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31723597

RESUMO

Skin-like sensory devices should be stretchable and self-healable to meet the demands for future electronic skin applications. Despite recent notable advances in skin-inspired electronic materials, it remains challenging to confer these desired functionalities to an active semiconductor. Here, we report a strain-sensitive, stretchable, and autonomously self-healable semiconducting film achieved through blending of a polymer semiconductor and a self-healable elastomer, both of which are dynamically cross-linked by metal coordination. We observed that by controlling the percolation threshold of the polymer semiconductor, the blend film became strain sensitive, with a gauge factor of 5.75 × 105 at 100% strain in a stretchable transistor. The blend film is also highly stretchable (fracture strain, >1300%) and autonomously self-healable at room temperature. We proceed to demonstrate a fully integrated 5 × 5 stretchable active-matrix transistor sensor array capable of detecting strain distribution through surface deformation.

16.
Adv Mater ; 31(41): e1902899, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31456271

RESUMO

All-polymer solar cells (all-PSCs) exhibit excellent stability and readily tunable ink viscosity, and are therefore especially suitable for printing preparation of large-scale devices. At present, the efficiency of state-of-the-art all-PSCs fabricated by the spin-coating method has exceeded 11%, laying the foundation for the preparation and practical utilization of printed devices. A high power conversion efficiency (PCE) of 11.76% is achieved based on PTzBI-Si:N2200 all-PSCs processing with 2-methyltetrahydrofuran (MTHF, an environmentally friendly solvent) and preparation of active layers by slot die printing, which is the top efficient for all-PSCs. Conversely, the PCE of devices processed by high-boiling point chlorobenzene is less than 2%. Through the study of film formation kinetics, volatile solvents can freeze the morphology in a short time, and a more rigid conformation with strong intermolecular interaction combined with the solubility limit of PTzBI-Si and N2200 in MTHF results in the formation of a fibril network in the bulk heterojunction. The multilength scaled morphology ensures fast transfer of carriers and facilitates exciton separation, which boosts carrier mobility and current density, thus improving the device performance. These results are of great significance for large-scale printing fabrication of high-efficiency all-PSCs in the future.

17.
Biosens Bioelectron ; 140: 111353, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31150982

RESUMO

Ultrasensitive detection of cancer biomarkers has shown great promise for precision medicine. Here, a triple signal amplification strategy was developed for analysis of carcinoembryonic antigen (CEA) by using MoS2-based nanocomposites. Gold nanoparticles-decorated molybdenum disulfide nanocomposite (MoS2-AuNPs) was used to construct the modified electrode and nanoprobe, which could efficiently amplify electrochemical signal due to its large surface area and high catalytic ability. Horseradish peroxidase (HRP)-labelled carcinoembryonic monoclonal antibody (anti-CEA) and HRP were used to co-construct the MoS2-based nanoprobe, which could further amplify the electrochemical signal by catalyzing o-phenylenediamine (o-PD) in the presence of hydrogen peroxide (H2O2). Expectedly, an excellent analytical performance for CEA detection was obtained, such as wide detection range (10 fg mL-1-1 ng mL-1), ultralow detection limit (1.2 fg mL-1), high selectivity and good stability, suggesting this immunosensor could detect CEA in real samples.


Assuntos
Técnicas Biossensoriais/métodos , Antígeno Carcinoembrionário/sangue , Dissulfetos/química , Ouro/química , Nanopartículas Metálicas/química , Molibdênio/química , Anticorpos Imobilizados/química , Técnicas Eletroquímicas/métodos , Humanos , Técnicas Imunoenzimáticas/métodos , Limite de Detecção
18.
Nat Mater ; 18(6): 594-601, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30988452

RESUMO

Stretchable semiconducting polymers have been developed as a key component to enable skin-like wearable electronics, but their electrical performance must be improved to enable more advanced functionalities. Here, we report a solution processing approach that can achieve multi-scale ordering and alignment of conjugated polymers in stretchable semiconductors to substantially improve their charge carrier mobility. Using solution shearing with a patterned microtrench coating blade, macroscale alignment of conjugated-polymer nanostructures was achieved along the charge transport direction. In conjunction, the nanoscale spatial confinement aligns chain conformation and promotes short-range π-π ordering, substantially reducing the energetic barrier for charge carrier transport. As a result, the mobilities of stretchable conjugated-polymer films have been enhanced up to threefold and maintained under a strain up to 100%. This method may also serve as the basis for large-area manufacturing of stretchable semiconducting films, as demonstrated by the roll-to-roll coating of metre-scale films.

19.
ACS Nano ; 13(4): 4018-4027, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30917283

RESUMO

Biological systems are able to control the assembly and positioning of proteins with nanoscale precision, as exemplified by the intricate molecular structures within cell membranes, virus capsids, and collagen matrices. Controlling the assembly of biomolecules is critical for the use of biomaterials in artificial systems such as antibacterial coatings, engineered tissue samples, and implanted medical devices. Furthermore, understanding the dynamics of protein assembly on heterogeneous templates will ultimately enable the control of protein crystallization in general. Here, we show a biomimetic, hierarchical bottom-up approach to direct the self-assembly of crystalline S-layers through nonspecific interactions with nanostructured block copolymer (BCP) thin-film templates. A comparison between physically and chemically patterned BCP substrates shows that chemical heterogeneity is required to confine the adhesion and self-assembly of S-layers to specific BCP domains. Furthermore, we show that this mechanism can be extended to direct the formation of collagen fibers along the principal direction of the underlying BCP substrate. The dynamics of protein self-assembly at the solid-liquid interface are followed using in situ high-resolution atomic force microscopy under continuous flow conditions, allowing the determination of the rate constants of the self-assembly. A pattern of alternating, chemically distinct nanoscale domains drastically increases the rate of self-assembly compared to non-patterned chemically homogeneous substrates.


Assuntos
Colágeno/química , Nanoestruturas/química , Polietilenoglicóis/química , Poliestirenos/química , Polivinil/química , Adsorção , Materiais Biomiméticos/química , Cristalização , Microscopia de Força Atômica , Propriedades de Superfície
20.
Adv Mater ; 31(7): e1806747, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30549332

RESUMO

Wafer-scale fabrication of high-performance uniform organic electronic materials is of great challenge and has rarely been realized before. Previous large-scale fabrication methods always lead to different layer thickness and thereby poor film and device uniformity. Herein, the first demonstration of 4 in. wafer-scale, uniform, and high-performance n-type polymer monolayer films is reported, enabled by controlling the multi-level self-assembly process of conjugated polymers in solution. Since the self-assembly process happened in solution, the uniform 2D polymer monolayers can be facilely deposited on various substrates, and theoretically without size limitations. Polymer monolayer transistors exhibit high electron mobilities of up to 1.88 cm2 V-1 s-1 , which is among the highest in n-type monolayer organic transistors. This method allows to easily fabricate n-type conjugated polymers with wafer-scale, high uniformity, low contact resistance, and excellent transistor performance (better than the traditional spin-coating method). This work provides an effective strategy to prepare large-scale and uniform 2D polymer monolayers, which could enable the application of conjugated polymers for wafer-scale sophisticated electronics.

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