Manufacture of Binary Nanofeatured Polymeric Films Using Nanosphere Lithography and Ultraviolet Roller Imprinting

This paper describes the manufacture of binary nanostructured films utilizing nanosphere lithography and ultraviolet (UV) roller imprinting. To manufacture the binary nanofeatured template, polystyrene nanocolloids of two distinct dimensions (900 and 300 nm) were primarily self-assembly spun coated on a silicon substrate. A roller imprinting facility equipped with polydimethylsiloxane molds and ultraviolet radiation was employed. During the imprinting procedure, the roller was steered by a motor and compressed the ultraviolet-curable polymeric layer against the glass substrate, where the nanofeatured layer was cured by the UV light source. Binary nanofeatured films were thus obtained. The influence of distinct processing variables on the imprinting of nanofeatured films was investigated. The empirical data suggested that with appropriate processing conditions, binary nanofeatured plastic films can be satisfactorily manufactured. It also demonstrated that roller imprinting combined with ultraviolet radiation can offer an easy yet effective method to prepare binary nanofeatured films, with a miniatured processing time and enhanced part quality.

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Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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Fast Fabrication of Nanostructured Films Using Nanocolloid Lithography and UV Soft Mold Roller Embossing: Effects of Processing Parameters

Polymers ◽

10.3390/polym13030405 ◽

2021 ◽

Vol 13 (3) ◽

pp. 405

Author(s):

Demei Lee ◽

Ya-Ling Tang ◽

Shih-Jung Liu

Keyword(s):

Uv Light ◽

Processing Parameters ◽

Polymeric Films ◽

Step Motor ◽

Silicon Substrates ◽

Casting Method ◽

Uv Curable ◽

Soft Mold ◽

Uv Curable Resin ◽

Spin Coater

We report the fabrication of nanofeatured polymeric films using nanosphere lithography and ultraviolet (UV) soft-mold roller embossing and show an illuminative example of their application to solar cells. To prepare the nanofeatured template, polystyrene nanocolloids of two distinct sizes (900 and 300 nm) were overlaid on silicon substrates using a spin coater. A lab-made soft-mold roller embossing device equipped with a UV light source was adopted. A casting method was employed to replicate the nanofeatured template onto polydimethylsiloxane, which was used as the soft mold. During the embossing procedure, the roller was driven by a step motor and compressed the UV-curable resin against the glass substrate to form the nanofeatured layer, which was subsequently cured by UV radiation. Polymer films with nanoscaled features were thus obtained. The influence of distinct processing variables on the reproducibility of the nanofeatured films was explored. The empirical outcomes demonstrate that UV soft-mold roller embossing offers a simple yet potent way of producing nanofeatured films.

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Binary Self-Assembly of Nanocolloidal Arrays using Concurrent and Sequential Spin Coating Techniques

Materials ◽

10.3390/ma14020274 ◽

2021 ◽

Vol 14 (2) ◽

pp. 274

Author(s):

Shih-Jyun Shen ◽

Demei Lee ◽

Yu-Chen Wu ◽

Shih-Jung Liu

Keyword(s):

Silicon Substrate ◽

Self Assembly ◽

Spin Coating ◽

Processing Parameters ◽

The Self ◽

Silicon Substrates ◽

Processing Conditions ◽

Polystyrene Spheres ◽

Optimal Processing ◽

Spin Coater

This paper reports the binary colloid assembly of nanospheres using spin coating techniques. Polystyrene spheres with sizes of 900 and 100 nm were assembled on top of silicon substrates utilizing a spin coater. Two different spin coating processes, namely concurrent and sequential coatings, were employed. For the concurrent spin coating, 900 and 100 nm colloidal nanospheres of latex were first mixed and then simultaneously spin coated onto the silicon substrate. On the other hand, the sequential coating process first created a monolayer of a 900 nm nanosphere array on the silicon substrate, followed by the spin coating of another layer of a 100 nm colloidal array on top of the 900 nm array. The influence of the processing parameters, including the type of surfactant, spin speed, and spin time, on the self-assembly of the binary colloidal array were explored. The empirical outcomes show that by employing the optimal processing conditions, binary colloidal arrays can be achieved by both the concurrent and sequential spin coating processes.

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Self-Assembly of Monolayers of Submicron Sized Particles on Thin Liquid Films

Volume 7A: Fluids Engineering Systems and Technologies ◽

10.1115/imece2013-65324 ◽

2013 ◽

Author(s):

Shriram Pillapakkam ◽

N. A. Musunuri ◽

P. Singh

Keyword(s):

Electric Field ◽

Self Assembly ◽

Uv Light ◽

Capillary Forces ◽

Liquid Films ◽

Thin Liquid Films ◽

Liquid Interfaces ◽

Uv Curable ◽

Particle Monolayer ◽

Uv Curable Resin

In this paper, we present a technique for freezing monolayers of micron and sub-micron sized particles onto the surface of a flexible thin film after the self-assembly of a particle monolayer on fluid-liquid interfaces has been improved by the process we have developed where an electric field is applied in the direction normal to the interface. Particles smaller than about 10 microns do not self-assemble under the action of lateral capillary forces alone since capillary forces amongst them are small compared to Brownian forces. We have overcome this problem by applying an electric field in the direction normal to the interface which gives rise to dipoledipole and capillary forces which cause the particles to arrange in a triangular pattern. The technique involves assembling the monolayer on the interface between a UV-curable resin and another liquid by applying an electric field, and then curing the resin by applying UV light. The monolayer becomes embedded on the surface of the solidified resin film.

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Ultraviolet Transparency of Plastic Films Determines the Quality of Lettuce (Lactuca sativa L.) Grown in a Greenhouse

Agronomy ◽

10.3390/agronomy11020358 ◽

2021 ◽

Vol 11 (2) ◽

pp. 358

Author(s):

Deissy Giovanna Quintero-Arias ◽

John Fabio Acuña-Caita ◽

Carlos Asensio ◽

Juan Luis Valenzuela

Keyword(s):

Ultraviolet Radiation ◽

High Altitude ◽

Dry Weight ◽

Yield Component ◽

Plastic Film ◽

Area Index ◽

Plastic Films ◽

High Solar Radiation ◽

Cycle Growth

The quality of red lettuce is based on the content of anthocyanin pigments, and the content of these pigments increases when the plant receives ultraviolet radiation. Lettuce crops are increasingly being grown in greenhouses to provide better quality fresh lettuce; however, both quality and productivity are affected by the type of cover used. The effects of UV-transparent and UV-blocking plastic films on the growth and quality of three lettuce cultivars (‘Casabella’ and ‘Vera’, which are both green leaf, and ‘Lollo Rosso’, which is red leaf) were investigated. The crop was cultivated at an altitude of 2576 m a.s.l. to naturally expose it to high ultraviolet radiation. The height and diameter of plants, fresh and dry weight, leaf area index, chlorophyll fluorescence, and leaf colour were determined throughout the crop cycle. Growth characteristics were not significantly influenced by the plastic film in all cultivars, probably due to the high altitude and the high solar radiation received. The UV-transparent film could increase the red colour in ‘Lollo Rosso’, and a higher commercial quality was achieved. No effect of the plastic film on the yield component was observed in the ‘Casabella’ and ‘Vera’ cultivars. The findings of this study provide guidance on what cultivar and plastic film must be used in high-altitude areas where the solar and UV radiation is high.

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Electron, Proton, and Ultraviolet Radiation Effects on Thermophysical Properties of Polymeric Films

Journal of Spacecraft and Rockets ◽

10.2514/2.3904 ◽

2002 ◽

Vol 39 (6) ◽

pp. 833-838 ◽

Cited By ~ 15

Author(s):

Dennis A. Russell ◽

John W. Connell ◽

Lawrence B. Fogdall

Keyword(s):

Ultraviolet Radiation ◽

Thermophysical Properties ◽

Radiation Effects ◽

Polymeric Films

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Inhibition of Salmonella typhimurium on Agar Medium and Poultry Skin by Ultraviolet Energy

Journal of Food Protection ◽

10.4315/0362-028x-59.3.319 ◽

1996 ◽

Vol 59 (3) ◽

pp. 319-321 ◽

Cited By ~ 32

Author(s):

SUSAN S. SUMNER ◽

EVA A. WALLNER-PENDLETON ◽

GLENN W. FRONING ◽

LA VERNE E. STETSON

Keyword(s):

Ultraviolet Radiation ◽

Salmonella Typhimurium ◽

Agar Medium ◽

Uv Light ◽

Light Treatment ◽

Complete Elimination ◽

Bacterial Reduction ◽

Colony Forming Units ◽

Ultraviolet Energy ◽

Different Doses

Ultraviolet radiation (UV) was effective in destroying Salmonella typhimurium on agar plates and poultry skin. Agar plates inoculated with varying numbers of colony-forming units (CFU) of S. typhimurium (1.2 × 102 to 1.7 × 109) were subjected to different doses of UV light to determine optimal killing. Poultry skin was also inoculated with varying CFU of S. typhimurium per 2 cm2 of skin and subjected to UV light. UV light treatment of inoculated agar plates revealed almost complete elimination (99.9%) of S. typhimurium at 2,000 μW · s · cm−2. Bacterial reduction was less effective on the surface of poultry skin when a 80.5% reduction in S. typhimurium was obtained at 2,000 μW · s · cm−2.

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PhotoATRP Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

10.26434/chemrxiv.12988559 ◽

2020 ◽

Author(s):

Ali Shahrokhinia ◽

Randall Scanga ◽

Priyanka Biswas ◽

James Reuther

Keyword(s):

Self Assembly ◽

Glycidyl Methacrylate ◽

Uv Light ◽

Copper Catalyst ◽

Crosslinking Agent ◽

Polymer Nanoparticles ◽

One Pot ◽

Responsive Polymer ◽

Catalyst Systems ◽

First Time

ABSTRACT: Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using ppm levels (ca. < 20 ppm) of copper catalyst at ambient temperature. Using CuIIBr2/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was per-formed all in one-pot starting from synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-crosslinked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and crosslinking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multi-block copolymers with temporal control via switching the UV light on and off. Further, core-crosslinking of PISA nanoparticles was performed via the slow incorporation of the CBMA enabling one-pot crosslinking during the PISA process. Finally, the disulfide installed in the CBMA core-crosslinks allowed for the stimuli-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.

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