3D-printing of ultra-high refractive index polymers
Sulfur copolymers having high sulfur content for use as raw materials in 3D printing. The sulfur copolymers are prepared by melting and copolymerizing one or more comonomers with cyclic selenium sulfide, elemental sulfur, elemental selenium, or a combination thereof. Optical substrates, such as films and lenses, are constructed from the sulfur copolymer via 3D printing and are substantially transparent in the visible and infrared spectrum. The optical substrates can have refractive indices of about 1.75-2.6 at a wavelength in a range of about 500 nm to about 8 μm.
1. A method of producing a substrate using 3D printing, said method comprising:
a. providing a print material comprising a sulfur copolymer, said sulfur copolymer formed from polymerization of:
i. one or more chalcogenic monomers at a level of at least 50 wt % of the sulfur copolymer, wherein the chalcogenic monomers contain sulfur and selenium; and
ii. one or more comonomers each selected from a group consisting of amine comonomers, thiol comonomers, sulfide comonomers, alkynylly unsaturated comonomers, epoxide comonomers, nitrone comonomers, aldehyde comonomers, ketone comonomers, thiirane comonomers, ethylenically unsaturated comonomers, styrenic comonomers, vinylic comonomers, methacrylate comonomers, acrylonitrile comonomers, allylic monomers, acrylate monomers, vinylpyridine monomers, isobutylene monomers, maleimide monomers, norbornene monomers, monomers having at least one vinyl ether moiety, and monomers having at least one isopropenyl moiety, at a level in the range of about 5-50 wt % of the sulfur copolymer;
b. introducing said print material into a 3D printer; and
c. dispensing said print material by successively applying layers of said print material to form the substrate;
wherein the substrate produced from the print material has a refractive index of about 1.75-2.6 at a wavelength in a range of about 500 nm to about 8 μm.
2. The method of claim 1 , wherein the chalcogenic monomers are cyclic selenium sulfide and isomers thereof or oligomers containing sulfur and selenium units.
3. The method of claim 2 , wherein the oligomer containing sulfur and selenium units is derived from elemental sulfur and elemental selenium.
4. The method of claim 2 , wherein the sulfur copolymer comprises at least about 30 wt % of sulfur.
5. The method of claim 3 , wherein the sulfur copolymer comprises at least about 30 wt % of elemental selenium.
6. The method of claim 2 , wherein the print material comprises at least about 30 wt % of sulfur, at least about 30 wt % of selenium, and about 15-25 wt % of the comonomers.
7. The method of claim 1 , wherein the chalcogenic monomers are polymerized with the one or more comonomers via free radical polymerization, controlled radical polymerization, ring-opening polymerization, ring-opening metathesis polymerization, step-growth polymerization, or chain-growth polymerization.
8. The method of claim 1 , wherein polymerizing the comonomers with the chalcogenic monomers enables at least one functional sulfur moiety of the chalcogenic monomers to bond with at least one functional moiety of the one or more monomers.
9. The method of claim 1 , wherein the print material is in a form of a filament, liquid, gel, or powder.
10. The method of claim 1 , further comprising dispensing a binding material to each layer of print material.
11. The method of claim 1 , further comprising activating the print material via thermal, chemical, thermochemical, or photo/light activation, or infrared photo-heating or photo-patterning, thereby hardening the print material to form the substrate.
12. The method of claim 1 , wherein the substrate produced from the print material is substantially transparent in an infrared or visible spectrum, wherein the transparent substrate is a film, a lens, or a free-standing object.
13. The method of claim 1 , wherein the substrate is an optical device component configured for use as a transmitting material in an infrared imaging device, wherein the optical device component is a lens, a window, a microlens array, a waveguide, a Bragg reflector, or an optical fiber.
14. A method of producing a substrate using stereolithography, said method comprising:
a. providing a liquid print material comprising a sulfur copolymer having photocurable moieties, said sulfur copolymer comprising:
i. one or more chalcogenic monomers at a level of at least 50 wt % of the sulfur copolymer, wherein the chalcogenic monomers contain sulfur and selenium; and
ii. one or more comonomers each selected from a group consisting of amine, comonomers, thiol comonomers, sulfide comonomers, alkynylly unsaturated comonomers, epoxide comonomers, nitrone comonomers, aldehyde comonomers, ketone comonomers, thiirane comonomers, ethylenically unsaturated comonomers, styrenic comonomers, vinylic comonomers, methacrylate comonomers, acrylonitrile comonomers, allylic monomers, acrylate monomers, vinylpyridine monomers, isobutylene monomers, maleimide monomers, norbornene monomers, monomers having at least one vinyl ether moiety, and monomers having at least one isopropenyl moiety, at a level in the range of about 5-50 wt % of the sulfur copolymer;
b. adding said liquid print material into a reservoir; and
c. selectively photopolymerizing said print material in the reservoir to produce the substrate;
wherein the photocurable moieties enable photopolymerization of said print material, wherein the substrate produced from the print material has a refractive index of about 1.75-2.6 at a wavelength in a range of about 500 nm to about 8 μm.
15. The method of claim 14 , wherein the chalcogenic monomers are cyclic selenium sulfide and isomers thereof or oligomers containing sulfur and selenium units.
16. The method of claim 15 , wherein the oligomer containing sulfur and selenium units is derived from elemental sulfur and elemental selenium.
17. The method of claim 15 , wherein the sulfur copolymer comprises at least about 30 wt % of sulfur.
18. The method of claim 16 , wherein the sulfur copolymer comprises at least about 30 wt % of elemental selenium.
19. The method of claim 15 , wherein the print material comprises at least about 30 wt % of sulfur, at least about 30 wt % of selenium, and about 15-25 wt % of the comonomers.
20. The method of claim 14 , wherein the photocurable moieties of the sulfur copolymer are selected from a group consisting of vinyl, epoxide, azide, cinnamate, coumarin, benzophenone, and unsaturated moieties.