A Unique Combination of Microlens and Pillar on Fiber Facet using UV-Curable Resin for High Optical Coupling to Silicon Photonics

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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Preparation of alkali-resistant PVDF membranes via immobilization of sodium lauryl sulfate (SDS) on surface

Applied Water Science ◽

10.1007/s13201-021-01377-6 ◽

2021 ◽

Vol 11 (3) ◽

Author(s):

Gongpu Wen ◽

Kun Chen ◽

Yanhong Zhang ◽

Yue Zhou ◽

Jun Pan ◽

...

Keyword(s):

Sodium Lauryl Sulfate ◽

Alkali Treatment ◽

Membrane Surface ◽

Alkali Resistance ◽

Lauryl Sulfate ◽

Uv Curable ◽

Pvdf Membrane ◽

Glycol Diacrylate ◽

Polyester Acrylate ◽

Uv Curable Resin

AbstractA novel strategy was proposed to fabricate alkali-resistant PVDF membrane via sodium lauryl sulfate (SDS) attached to the surface of membrane and immobilized by UV-curable polyester acrylate and tri(propylene glycol) diacrylate (TPGDA). The attached anionic surfactant, SDS, on the membrane surface can resist the alkali corrosion by NaOH, and the curing of the resin can immobilize the SDS on the membrane firmly. Due to the unique alkali resistance of SDS and resin formed, the UV-curable resin-modified PVDF membrane showed greatly enhanced alkali-resistant ability. Characterization of SEM and FTIR showed that polyester acrylate and TPGDA were cured successfully under the action of 1-hydroxycyclohexyl phenyl ketone (184) and ultraviolet light. Whiteness, differential scanning calorimeter and X-ray photoelectron spectrometer characterization showed that the modified PVDF membrane had a lower degree of dehydrofluorination than the pristine PVDF membrane after alkali treatment. Results of the detailed alkali-resistant analysis indicated that the F/C ratio of the UV-curable resin-modified PVDF membrane decreased by 2.6% after alkali treatment compared to pristine PVDF membrane decreased by 19.28%. The alkali-resistant performance was mainly attributed to the immobilized SDS. This study provided a facile and scalable method for designing alkali-resistant PVDF membrane, which shows a promising potential in the treatment of alkaline wastewater and alkaline-cleaning PVDF membrane.

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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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