Fabrication Of Photonic Materials Research Articles

Designing and Tailoring Optical Properties: Theory and Simulation of Photonic Band Gaps in Photonic Materials

Theoretical calculations and numerical simulations play a crucial role in analyzing material properties and devising effective research strategies. In this study, the photonic band gap (PBG) of polymethyl methacrylate (PMMA) and polystyrene (PS) photonic crystals was successfully predicted using theoretical calculations and numerical simulations. The agreement between the predicted results and the actual reflection peaks reached an impressive level of 99%. Utilizing SEM images, the prediction of reflection peaks in acrylamide (AM)—based photonic hydrogels was conducted using theoretical formulas and Rsoft 2019–Bandsolve software v2019.09. The relationship between the actual reflection peaks and compressive strains in AM-based photonic hydrogels featuring 251 nm PMMA PCs exhibited a remarkable similarity of over 96% with the theoretical and simulated results. In conclusion, an exploration was conducted into the relationship between reflection peaks and compressive strains for AM-based 270 nm PMMA photonic hydrogels, allowing the prediction of the actual reflection peaks under compression. The consistency observed between theoretical/simulated reflection peaks and actual reflection peaks validates the efficacy of this approach in evaluating the optical properties of photonic materials and predicting their responsive effects. This method offers a straightforward and expeditious solution for the design and fabrication of photonic materials.

2-D assembly of colloidal particles on a planar electrode

Electrical voltage externally applied between parallel-plate electrodes can cause colloidal particles located near one of the electrodes to aggregate; thus monodisperse particles can be driven to form hexagonally close-packed arrays which can be useful in the fabrication of photonic materials. The mechanism for lateral motion of particles on the electrode surface is electroosmotic flow driven by the action of the applied electric field acting either on the equilibrium charges in the diffuse layer of the particles (ECEO) or on charge induced by the electric field on the surface of the electrode (ICEO). For steady currents, ECEO dominates whereas ICEO dominates for high-frequency alternating current. For intermediate frequencies (10 Hz to 1 kHz) both mechanisms are active. This critical review attempts to integrate concepts from electrochemistry and colloid chemistry to understand this electrokinetic phenomenon.

Synthesis of Comb Block Copolymers by ROMP, ATRP, and ROP and Their Assembly in the Solid State

This article reports the synthesis of comb block copolymers with backbones from exo-norbornene esters via ring-opening metathesis polymerizations (ROMP) and arms composed of polystyrene and polylactide. These polymers represent an exciting new architecture of polymers that have applications in the fabrication of photonic materials and nanofluidic systems. The living polymerization of block copolymers by ROMP with degrees of polymerization up to 2000 units and polydispersities less than 1.2 are described. This result is important as it extends the range of block copolymers that can be synthesized by ROMP to include those with high molecular weights. Comb block copolymers were grown from these block copolymers as they displayed initiators for the ring-opening polymerization of lactide and the atom transfer radical polymerization of styrene. Comb block copolymers with polystyrene and polylactide arms were synthesized with molecular weights up to 63 000 000 g mol-1. The polystyrene arms had narrow polydispersities and molecular weights in excess of 10 000 g mol-1; this result showed that the polymerization of styrene was well controlled. The sizes and shapes of these comb polymers were characterized by multiangle laser light scattering and scanning probe microscopy and demonstrated that some of these polymers were shaped as rigid rods with lengths in excess of 300 nm. To demonstrate their potential as photonic materials, an example of a comb block copolymer was assembled in the solid state with domain sizes exceeding 100 nm and characterized by scanning electron microscopy.