Patterned Phosphonium-Functionalized Photopolymer Networks as Ceramic Precursors

Abstract

In an attempt to address the growing demand for well-defined metallized regions for electronic applications, we developed a new method of forming patterned ceramics. Using UV-curing to synthesize a phosphonium-containing semi-interpenetrating polymer network (S-IPN) followed by ion exchange on the surface with a bis­(phosphino)­borate molybdenum tetracarbonyl complex (2Mo) results in 71% ion exchange of 2Mo to phosphonium sites by attenuated total reflectance infrared (ATR-IR) spectroscopy. The functionalized films were pyrolyzed at temperatures ranging between 800 and 1000 °C to create Mo-containing ceramics. The polymer network can be patterned using electron beam lithography prior to the metal functionalization step. The patterns had good shape retention after metal functionalization and pyrolysis. The polymer networks were characterized using ATR-IR spectroscopy, thermogravimetric analysis, and differential scanning calorimetry, and the swellability and gel content were determined. The resulting ceramics were characterized using optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and powder X-ray diffraction.

Antimony‐Functionalized Phosphine‐Based Photopolymer Networks

“…[17] This is corroborated by the XPS data that shows the identity of Pinthe char to be phosphate.The PXRD patterns for all three materials match that of Sb metal [28] with no superimposed sharp signals,i ndicating all other components of the char are amorphous.T he char can be characterized as doped carbon black with low crystallinity based on the high C content, broad low angle signals (< 1008 8 2q)i nt he PXRD pattern and the presence of carboxyl, ketone,a lcohol, and ether CX PS signals typical of carbon black (see Supporting Information). Given the highly oxophilic nature of P, the formation of P 4 O 10 and its sublimation (360 8 8C) during the pyrolysis experiment is likely.…”

“…We are currently working on expanding the compositional range of the system using coordination chemistry of metallic and non-metallic elements and are geared towards taking advantage of the ease of shaping photopolymer networks [17] to pattern polymer derived ceramics on the micro scale. The phosphane-ene platform is ap romising material to allow diverse control over composition.…”

“…[10][11][12][13][14][15][16] These systems provide spatial and compositional control through the polymer precursor owing to the presence of metals in the segregated domains. [17] Them ain advantage to photopolymer networks in this context is that they can be shaped before,during,and after irradiation by molding, masking,and lithographic techniques,r espectively. Recently we have shown that asimilar effect can be achieved by metal functionalization of ap atterned, phosphorus-based photopolymer network.…”

“…Upon pyrolysis,t he composition and shape of the resulting ceramics are dictated by that of the polymer precursor. [17,18] This ability to be shaped at multiple points in aprocess opens several potential avenues to gain spatial control over the ceramic precursor. [17] Them ain advantage to photopolymer networks in this context is that they can be shaped before,during,and after irradiation by molding, masking,and lithographic techniques,r espectively.…”

“…[17][18][19][20][21] Thecoordination chemistry of phosphines is rich and the phosphine sites within phosphane-ene networks can be accessed using simple solution chemistry common to small molecule phosphines. [17][18][19][20][21] Thecoordination chemistry of phosphines is rich and the phosphine sites within phosphane-ene networks can be accessed using simple solution chemistry common to small molecule phosphines.…”