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1.
Small ; 20(4): e2305460, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37726244

RESUMO

Polymer elastomers with reversible shape-changing capability have led to significant development of artificial muscles, functional devices, and soft robots. By contrast, reversible shape transformation of inorganic nanoparticles is notoriously challenging due to their relatively rigid lattice structure. Here, the authors demonstrate the synthesis of shape-changing nanoparticles via an asymmetrical surface functionalization process. Various ligands are investigated, revealing the essential role of steric hindrance from the functional groups. By controlling the unbalanced structural hindrance on the surface, the as-prepared clay nanoparticles can transform their shape in a fast, facile, and reversible manner. In addition, such flexible morphology-controlled mechanism provides a platform for developing self-propelled shape-shifting nanocollectors. Owing to the ion-exchanging capability of clay, these self-propelled nanoswimmers (NS) are able to autonomously adsorb rare earth elements with ultralow concentration, indicating the feasibility of using naturally occurring materials for self-powered nanomachine.

2.
Proc Natl Acad Sci U S A ; 116(37): 18322-18327, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31444300

RESUMO

Photonic materials with positionally ordered structure can interact strongly with light to produce brilliant structural colors. Here, we found that the nonperiodic nematic liquid crystals of nanoplates can also display structural color with only significant orientational order. Owing to the loose stacking of the nematic nanodiscs, such colloidal dispersion is able to reflect a broad-spectrum wavelength, of which the reflection color can be further enhanced by adding carbon nanoparticles to reduce background scattering. Upon the addition of electrolytes, such vivid colors of nematic dispersion can be fine-tuned via electrostatic forces. Furthermore, we took advantage of the fluidity of the nematic structure to create a variety of colorful arts. It was expected that the concept of implanting nematic features in photonic structure of lyotropic nanoparticles may open opportunities for developing advanced photonic materials for display, sensing, and art applications.

3.
J Environ Manage ; 238: 257-262, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30852402

RESUMO

A facile one-step microwave-assisted method was proposed for kaolinite intercalation and grafting. The structure, morphology, composition, and size distribution of kaolinite sheets were investigated using various methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis. The potential application of the modified kaolinite as an oil/water emulsion stabilizer was studied. The results verified that intact kaolinite sheets were obtained. The dodecane/water emulsion stabilized by the modified kaolinite remained stable for more than 60 days. The effective performance suggests that the effectiveness of the proposed kaolinite modification method may be useful for Pickering emulsion stabilization in oil recovery applications.


Assuntos
Caulim , Micro-Ondas , Emulsões , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Ecotoxicol Environ Saf ; 154: 27-35, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29454268

RESUMO

The occurrence, distribution, bioconcentration and diet safety via seafood consumption of 19 antibiotics were investigated in eight closed mariculture ponds, four estuaries, two nearshore areas and one offshore area from the Beibu Gulf. Seventeen, 16, 15 and 7 antibiotics were detected at total concentrations of 43.2 - 885 ng L-1, 22.4 - 118 ng L-1, 22.7 - 24.5 ng L-1, and 1.81-3.23 ng L-1 in the water of the above different areas, respectively. This indicates that the mariculture ponds are important sources of antibiotic pollution on the coast of the Beibu Gulf. Ten antibiotics were detected in feed samples with concentrations ranging from 0.03 to 95.4 ng g-1, demonstrating the presence of antibiotics in the feed and/or residual antibiotics in the raw material of the feed. The field bioconcentration factors (BCFs) of the antibiotics calculated in different culture organisms ranged from 0.55 to 10,774 L kg-1. The estimated daily intakes (EDIs) of sulphonamides, fluoroquinolones, macrolides and chloramphenicols via aquatic products were 19.8-105, 33.7-178, 34.9-186 and 6.9-37.1 ng d-1, respectively. According to the acceptable daily intakes (ADIs) and maximum residue limits (MRLs) proposed by different organisations, these aquatic products (shrimp, crab and oyster) reached the standard of safe consumption and could not pose a health risk to humans. However, a potential elevated risk to humans may remain because of the occurrence of multiple antibiotics in the cultured organisms, particularly for sensitive populations, such as pregnant women, the elderly and children.


Assuntos
Antibacterianos/análise , Aquicultura , Monitoramento Ambiental/métodos , Estuários , Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Criança , China , Exposição Dietética/análise , Inocuidade dos Alimentos , Humanos , Alimentos Marinhos/normas
5.
Angew Chem Int Ed Engl ; 57(36): 11752-11757, 2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-29987910

RESUMO

Dynamically engineering the interfacial interaction of nanoparticles has emerged as a new approach for bottom-up fabrication of smart systems to tailor molecular diffusion and controlled release. Janus zwitterionic nanoplates are reported that can be switched between a locked and unlocked state at interfaces upon changing surface charge, allowing manipulation of interfacial properties in a fast, flexible, and switchable manner. Combining experimental and modeling studies, an unambiguous correlation is established among the electrostatic energy, the interface geometry, and the interfacial jamming states. As a proof-of-concept, the well-controlled interfacial jamming of nanoplates enabled the switchable molecular diffusion through liquid-liquid interfaces, confirming the feasibility of using nanoparticle-based surfactants for advanced controlled release.

6.
Pediatr Blood Cancer ; 62(5): 759-65, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25464386

RESUMO

BACKGROUND: A growing collection of retrospective studies have suggested that TP53 mutations and/or CDKN2A deletions have prognostic significance in Ewing sarcoma. We sought to evaluate these variables in patients with localized disease treated prospectively on a single Children's Oncology Group protocol. PROCEDURE: Of the 568 patients enrolled on Children's Oncology Group protocol AEWS0031 (NCT00006734), 112 had tumor specimens of sufficient quality and quantity to allow for analysis of TP53 mutations status by DNA sequencing, and CDKN2A deletion by dual color fluorescent in situ hybridization. RESULTS: Eight of 93 cases (8.6%) were found to have TP53 point mutations and 12 of 107 cases (11.2%) demonstrated homozygous CDKN2A deletion. Two cases were found to have an alteration in both genes. There was no significant difference in event-free survival of patients with TP53 mutations and/or CDKN2A deletions compared to patients with normal TP53/CDKN2A gene status, as demonstrated by log rank test (p = 0.58). CONCLUSIONS: Although previous retrospective studies suggest their significance, TP53 mutation and/or CDKN2A deletion are not reliable prognostic biomarkers in localized Ewing sarcoma.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Ósseas/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Deleção de Genes , Mutação/genética , Sarcoma de Ewing/genética , Proteína Supressora de Tumor p53/genética , Adolescente , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/patologia , Criança , Feminino , Seguimentos , Humanos , Hibridização in Situ Fluorescente , Masculino , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Prognóstico , Estudos Prospectivos , Sarcoma de Ewing/mortalidade , Sarcoma de Ewing/patologia , Taxa de Sobrevida
7.
Polymers (Basel) ; 16(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891428

RESUMO

Carbon dots (CDs) have aroused colossal attention in the fabrication of nanocomposite membranes ascribed to their ultra-small size, good dispersibility, biocompatibility, excellent fluorescence, facile synthesis, and ease of functionalization. Their unique properties could significantly improve membrane performance, including permeance, selectivity, and antifouling ability. In this review, we summarized the recent development of CDs-based nanocomposite membranes in many application areas. Specifically, we paid attention to the structural regulation and functionalization of CDs-based nanocomposite membranes by CDs. Thus, a detailed discussion about the relationship between the CDs' properties and microstructures and the separation performance of the prepared membranes was presented, highlighting the advantages of CDs in designing high-performance separation membranes. In addition, the excellent optical and electric properties of CDs enable the nanocomposite membranes with multiple functions, which was also presented in this review.

9.
Front Neurol ; 13: 945439, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212661

RESUMO

[This corrects the article DOI: 10.3389/fneur.2020.543013.].

10.
ACS Appl Mater Interfaces ; 14(5): 7486-7492, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35080854

RESUMO

Graphene quantum dots (GQDs) are a subset of the nanocarbon material family, which promise a wide spectrum of applications. Herein, we describe amphiphilic graphene quantum dots with zwitterionic features (ZGQDs), which are able to stabilize the oil/water interface. ZGQDs were fabricated by modifying GQDs with tertiary amine groups and alkyl groups. Moreover, the blocking and unblocking behavior of ZGQDs at the oil/water interface could be tuned by adjusting pH values in the aqueous phase. It would provide a flexible and adjustable method to manipulate interfacial properties of ZGQDs, which enabled a switchable molecular diffusion through a fluid-fluid interface. ZGQDs have shown well-controlled interfacial behavior under different pH conditions, indicating great potential for applications in controlled molecular diffusion based on nanoparticles demonstrated in this work.

11.
AACE Clin Case Rep ; 8(6): 259-263, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36447829

RESUMO

Background: Adrenal Cushing syndrome (CS) is usually benign in etiology; however, although rarely, it can be due to adrenocortical carcinoma (ACC); in which case, diagnosis and management are quite complicated. Case Report: A 34-year-old woman presented with worsening confusion, weight gain, new-onset diabetes, and hypertension. Her history was significant for a 7.4-cm left adrenal mass and CS, which were treated with left adrenalectomy 2 years ago. She received hydrocortisone replacement therapy after the surgery, which was discontinued on admission when evaluation showed hypokalemia, hypercortisolemia, and undetectable adrenocorticotropic hormone. Subsequent testing included 1-mg and 8-mg dexamethasone suppression tests, which did not suppress cortisol; late-night salivary cortisol measurement, which yielded a very high salivary cortisol level; and 24-hour urinary cortisol measurement. The level of 11-deoxycortisol was elevated. A computed tomography scan revealed multiple hepatic lesions, which were fluorodeoxyglucose avid, and a biopsy confirmed metastatic ACC. She received treatment with mitotane, metyrapone (later changed to mifepristone), doxorubicin, cisplatin, and etoposide. Over 8 weeks, mitotane levels became therapeutic at 20 mcg/mL, the hepatic masses decreased in size, and she transitioned to adrenal insufficiency and improved glycemic control. Next-generation sequencing of liver biopsy and germline testing revealed a frameshift loss-of-function allelic variant in the FH gene that encodes the protein fumarate hydratase. Discussion: We report a case of recurrent CS due to metastatic ACC in a patient with a previously resected adrenal adenoma and FH allelic variant. Conclusion: Metastatic ACC presenting with severe CS presents a diagnostic and management challenge where combination therapy guided by a multidisciplinary team is essential. FH allelic variant may contribute to ACC progression.

12.
Mod Pathol ; 24(3): 430-42, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21076462

RESUMO

Renal cell carcinoma represents a model for contemporary classification of solid tumors; however, unusual and unclassifiable cases exist and are not rare in children and young adults. The anaplastic lymphoma kinase (ALK) gene has recently been implicated in subsets of pulmonary, esophageal, breast, and colon cancers. These findings strengthen the importance of molecular classification of carcinomas across different organ sites, especially considering the evolving targeted anticancer therapies with ALK inhibitors. In the current study of six pediatric renal cell carcinomas, two cases exhibited structural karyotypic abnormalities involving the ALK locus on chromosomal band 2p23. Fluorescence in situ hybridization (FISH) studies were positive for an ALK rearrangement in one case, and subsequent 5' rapid amplification of cDNA ends analysis of this tumor revealed that the 3' portion of the ALK transcript encoding for the kinase domain was fused in frame to the 5' portion of vinculin (VCL, NM_003373). The new fusion gene is predicted to have an open reading frame of 4122 bp encoding for a 1374-aa oncoprotein; its expression was shown by immunoblotting with anti-VCL and anti-ALK antibodies in tumor tissue lysates. Immunohistochemistry with the same antibodies demonstrated cytoplasmic and subplasmalemmal localization of the oncoprotein determined by its N-terminal VCL portion. FISH with a custom-designed VCL-ALK dual-fusion probe set confirmed the presence of the fusion in neoplastic cells and demonstrated the potential clinical utility of this approach for detecting VCL-ALK in routinely processed tissue. The five remaining pediatric renal cell carcinomas did not show ALK rearrangement by FISH or ALK expression by immunohistochemistry. The data identify the kidney as a new organ site for ALK-associated carcinomas and VCL as a novel ALK fusion partner. The results should prompt further studies to advance the molecular classification of renal cell carcinoma and help to select patients who would benefit from appropriate targeted therapies.


Assuntos
Carcinoma de Células Renais/genética , Fusão Gênica , Neoplasias Renais/genética , Receptores Proteína Tirosina Quinases/genética , Vinculina/genética , Adolescente , Quinase do Linfoma Anaplásico , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Criança , Aberrações Cromossômicas , Bandeamento Cromossômico , Cromossomos Humanos Par 2 , Feminino , Humanos , Hibridização in Situ Fluorescente , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Masculino , Receptores Proteína Tirosina Quinases/metabolismo , Vinculina/metabolismo
13.
Genes Chromosomes Cancer ; 49(9): 810-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20607705

RESUMO

Chondroid lipoma, a rare benign adipose tissue tumor, may histologically resemble myxoid liposarcoma or extraskeletal myxoid chondrosarcoma, but is genetically distinct. In this study, an identical reciprocal translocation, t(11;16)(q13;p13), was identified in three chondroid lipomas, a finding consistent with previously isolated reports. A fluorescence in situ hybridization (FISH)-based positional cloning strategy using a series of bacterial artificial chromosome (BAC) probe combinations designed to narrow the 16p13 breakpoint revealed MKL2 as the candidate gene. Subsequent 5' RACE studies demonstrated C11orf95 as the MKL2 fusion gene partner. MKL/myocardin-like 2 (MKL2) encodes myocardin-related transcription factor B in a megakaryoblastic leukemia gene family, and C11orf95 (chromosome 11 open reading frame 95) is a hypothetical protein. Sequencing analysis of reverse transcription-polymerse chain reaction (RT-PCR) generated transcripts from all three chondroid lipomas defined the fusion as occurring between exons 5 and 9 of C11orf95 and MKL2, respectively. Dual-color breakpoint spanning probe sets custom-designed for recognition of the translocation event in interphase cells confirmed the anticipated rearrangements of the C11orf95 and MKL2 loci in all cases. The FISH and RT-PCR assays developed in this study can serve as diagnostic adjuncts for the identification of this novel C11orf95-MKL2 fusion oncogene in chondroid lipoma.


Assuntos
Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 16/genética , Lipoma/genética , Fusão Oncogênica/genética , Fatores de Transcrição/genética , Translocação Genética/genética , Adulto , Idoso , Feminino , Humanos , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Pessoa de Meia-Idade , Fases de Leitura Aberta , RNA Mensageiro/genética , RNA Neoplásico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
14.
J Colloid Interface Sci ; 601: 106-113, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34058546

RESUMO

HYPOTHESIS: Stimuli-responsive Pickering emulsions have attracted considerable interest due to their widespread potential applications. Especially pH-responsive behavior could be easily implemented. In this work, we reported a pH-responsive Pickering emulsion based on amphiphilic graphene quantum dots at a low concentration which shows a great potential from the environmental and economic perspective. The stimuli responsive properties would make the smart Pickering emulsifiers recyclable and reusable. EXPERIMENTS: The amphiphilic-adaptable graphene quantum dots functionalized by alkyl groups (C-GQDs) were synthesized by a facile one-step pyrolysis method. The pH-responsive emulsion performances were investigated, and the mechanism of pH-responsive of C-GQDs was studied by dynamic light scattering. FINDINGS: The amphiphilicity of C-GQDs could be acquired controllably and effectively by this facile one-step pyrolysis method, which are able to stabilize Pickering emulsion at a very low concentration (0.001%). The amphiphilicity of C-GQDs are capable of changing in response to environmental stimuli. When the pH value of aqueous solution adjusts to 2, these C-GQDs aggregate in contrast to their stability in neutral condition due to the alternation of surface charges. The pH-responsive aggregation/ dispersion behavior of C-GQDs allows us to tune the interactions between oil-in-water emulsion droplets without introduction of destabilization agents. This will provide huge economic benefits in industrial applications in the future.


Assuntos
Grafite , Pontos Quânticos , Emulsões , Concentração de Íons de Hidrogênio , Tamanho da Partícula
15.
Mater Horiz ; 8(3): 758-802, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34821315

RESUMO

Water scarcity has become an increasingly complex challenge with the growth of the global population, economic expansion, and climate change, highlighting the demand for advanced water treatment technologies that can provide clean water in a scalable, reliable, affordable, and sustainable manner. Recent advancements on 2D nanomaterials (2DM) open a new pathway for addressing the grand challenge of water treatment owing to their unique structures and superior properties. Emerging 2D nanostructures such as graphene, MoS2, MXene, h-BN, g-C3N4, and black phosphorus have demonstrated an unprecedented surface-to-volume ratio, which promises ultralow material use, ultrafast processing time, and ultrahigh treatment efficiency for water cleaning/monitoring. In this review, we provide a state-of-the-art account on engineered 2D nanomaterials and their applications in emerging water technologies, involving separation, adsorption, photocatalysis, and pollutant detection. The fundamental design strategies of 2DM are discussed with emphasis on their physicochemical properties, underlying mechanism and targeted applications in different scenarios. This review concludes with a perspective on the pressing challenges and emerging opportunities in 2DM-enabled wastewater treatment and water-quality monitoring. This review can help to elaborate the structure-processing-property relationship of 2DM, and aims to guide the design of next-generation 2DM systems for the development of selective, multifunctional, programmable, and even intelligent water technologies. The global significance of clean water for future generations sheds new light and much inspiration in this rising field to enhance the efficiency and affordability of water treatment and secure a global water supply in a growing portion of the world.


Assuntos
Grafite , Nanoestruturas , Purificação da Água , Fósforo , Abastecimento de Água
16.
Int J Cancer ; 126(2): 315-27, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19676054

RESUMO

Uridine diphosphate (UDP)-glucose dehydrogenase (UGDH) catalyzes the oxidation of UDP-glucose to yield UDP-glucuronic acid, a precursor for synthesis of glycosaminoglycans and proteoglycans that promote aggressive prostate cancer (PC) progression. The purpose of our study was to determine if the UGDH expression in normal appearing acini (NAA) from cancerous glands is a candidate biomarker for PC field disease/effect assayed by quantitative fluorescence imaging analysis (QFIA). A polyclonal antibody to UGDH was titrated to saturation binding and fluorescent microscopic images acquired from fixed, paraffin-embedded tissue slices were quantitatively analyzed. Specificity of the assay was confirmed by Western blot analysis and competitive inhibition of tissue labeling with the recombinant UGDH. Reproducibility of the UGDH measurements was high within and across analytical runs. Quantification of UGDH by QFIA and Reverse-Phase Protein Array analysis were strongly correlated (r = 0.97), validating the QFIA measurements. Analysis of cancerous acini (CA) and NAA from PC patients vs. normal acini (NA) from noncancerous controls (32 matched pairs) revealed significant (p < 0.01) differences, with CA (increased) vs. NA, NAA (decreased) vs. NA and CA (increased) vs. NAA. Areas under the Receiver Operating Characteristic curves were 0.68 (95% CI: 0.59-0.83) for NAA and 0.71 (95% CI: 0.59-0.83) for CA (both vs. NA). These results support the UGDH content in prostatic acini as a novel candidate biomarker that may complement the development of a multi-biomarker panel for detecting PC within the tumor adjacent field on a histologically normal biopsy specimen.


Assuntos
Biomarcadores Tumorais/metabolismo , Próstata/enzimologia , Neoplasias da Próstata/enzimologia , Uridina Difosfato Glucose Desidrogenase/metabolismo , Idoso , Biópsia , Western Blotting , Linhagem Celular Tumoral , Humanos , Masculino , Microscopia de Fluorescência , Pessoa de Meia-Idade , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Análise Serial de Proteínas/métodos , Sensibilidade e Especificidade
17.
Front Neurol ; 11: 543013, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33281697

RESUMO

Objective: To explore the clinical related factors of neonatal hand-foot-mouth disease (HFMD) complicated with encephalitis. Method: The neonatal HFMD complicated with encephalitis treated in our hospital from July 2015 to July 2020 was taken as the object of study. According to the NBNA score at discharge, the patients were divided into normal group and abnormal group. The clinical symptoms, auxiliary examination and prognosis of the two groups were compared. Result: (1) General condition: there was no significant difference in sex, age, duration of fever, treatment time and etiological test between the two groups (P > 0.05). (2) Clinical symptoms and signs: there was significant difference in abnormal consciousness between the two groups (P < 0.05). However, there was no significant difference in skin rash, respiratory system symptoms, digestive system symptoms, signs of high intracranial pressure, increased muscle tone and weakening of primitive reflex (P > 0.05). (3) Auxiliary examination: the number of white blood cells and the level of cytokines (CK-BB, UCH-L1) in cerebrospinal fluid (CSF) in the group with abnormal NBNA score were significantly higher than those in the group with normal NBNA score (P < 0.05). The serum IgM level in the abnormal NBNA score group was higher than that in the normal NBNA score group, and the serum IgG level in the abnormal NBNA score group was lower than that in the normal NBNA score group, and the difference was statistically significant (P < 0.05). The abnormal rate of Craniocerebral MRI in abnormal NBNA score group was higher than that in normal NBNA score group, and there was significant difference between the two groups (P < 0.05). There was no significant difference in the levels of protein, sugar, chloride, lactate dehydrogenase, and MMP-9 in CSF and the abnormal rate of amplitude integrated EEG (aEEG) between the two groups (P > 0.05). (4) The prognoses of patients with normal and abnormal NBNA score are good, and there are not significantly differences in the prognosis between the two groups (P > 0.05). Conclusion: (1) Neonatal HFMD complicated with encephalitis occurs more than 10 days after birth, there is no obvious abnormality in male and female, the vast majority of newborns have febrile symptoms, rash is not its specific manifestation, and most of them are atypical. (2) The positive rate of HFMD-related virus detected in CSF of neonatal HFMD is high. For newborns with abnormal consciousness, CSF examination should be accomplished in time, which has certain clinical significance for early diagnosis and treatment of severe newborns. (3) The increase of white blood cell count and cytokines (CK-BB, UCH-L1) in CSF of neonatal HFMD complicated with encephalitis has a certain clinical reference value for early diagnosis and identification of severe newborns. (4) There is a certain humoral immune disorder in newborns with HFMD complicated with encephalitis, but the overall prognosis is better due to the protective effect of maternal IgG.

18.
Adv Mater ; 32(39): e2003081, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32851710

RESUMO

Printing techniques using nanomaterials have emerged as a versatile tool for fast prototyping and potentially large-scale manufacturing of functional devices. Surfactants play a significant role in many printing processes due to their ability to reduce interfacial tension between ink solvents and nanoparticles and thus improve ink colloidal stability. Here, a colloidal graphene quantum dot (GQD)-based nanosurfactant is reported to stabilize various types of 2D materials in aqueous inks. In particular, a graphene ink with superior colloidal stability is demonstrated by GQD nanosurfactants via the π-π stacking interaction, leading to the printing of multiple high-resolution patterns on various substrates using a single printing pass. It is found that nanosurfactants can significantly improve the mechanical stability of the printed graphene films compared with those of conventional molecular surfactant, as evidenced by 100 taping, 100 scratching, and 1000 bending cycles. Additionally, the printed composite film exhibits improved photoconductance using UV light with 400 nm wavelength, arising from excitation across the nanosurfactant bandgap. Taking advantage of the 3D conformal aerosol jet printing technique, a series of UV sensors of heterogeneous structures are directly printed on 2D flat and 3D spherical substrates, demonstrating the potential of manufacturing geometrically versatile devices based on nanosurfactant inks.

19.
ACS Appl Mater Interfaces ; 11(43): 40099-40106, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31589395

RESUMO

The ability of self-propelled nanoparticles to convert environmental energy into locomotion has led to several nanomotor prototypes that are promising in numerous real-world applications. However, the vast variety of nanoparticle designs prevents rapid identification of the optimal composition for a given application. In this study, we applied machine learning methods to predict the self-propulsion speed and water-cleaning efficiency of micro/nanomotors (MNMs), where the quality of machine learning predictions was evaluated based on the statistical values. The average absolute error of predicted velocity and predicted efficiency are determined to be as low as 0.10 and 0.12, respectively. In addition, by comparing the prediction results based on 13 features using four different machine learning algorithms, we are able to identify several key features that are important to effectively environmental decontamination, such as particle size, catalyst type, and aspect ratio. Following the guidelines deduced from these models, a high-efficiency Pt-coated nanomotor was designed and synthesized, of which the experimental results were compared with the machine learning predictions, showing an accurate prediction with a less than 15% of prediction error. In the range of our theoretical/experimental conditions, we showed that a gradient boosting algorithm is the most promising method for predicting the environmental decontamination behavior of MNMs, a machine-learning algorithm rarely used in the nanomaterial field in current practice.

20.
Sci Rep ; 9(1): 163, 2019 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-30655562

RESUMO

Janus colloidal surfactants with opposing wettabilities are receiving attention for their practical application in industry. Combining the advantages of molecular surfactants and particle-stabilized Pickering emulsions, Janus colloidal surfactants generate remarkably stable emulsions. Here we report a straightforward and cost-efficient strategy to develop Janus nanoplate surfactants (JNPS) from an aluminosilicate nanoclay, halloysite, by stepwise surface modification, including an innovative selective surface modification step. Such colloidal surfactants are found to be able to stabilize Pickering emulsions of different oil/water systems. The microstructural characterization of solidified polystyrene emulsions indicates that the emulsion interface is evenly covered by JNPS. The phase behaviors of water/oil emulsion generated by these novel platelet surfactants were also investigated. Furthermore, we demonstrate the application of JNPS for enhanced oil recovery with a microfluidic flooding test, showing a dramatic increase of oil recovery ratio. This research provides important insights for the design and synthesis of two-dimensional Janus colloidal surfactants, which could be utilized in biomedical, food and mining industries, especially for circumstances where high salinity and high temperature are involved.

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