POLYCARBOMETHYLSILANE

• CAS: 62306-27-8
• Catalog Number: ACM62306278
• Category: Main Products
• Molecular Weight: Mn 1000-2000
• Molecular Formula: (C2H6Si)n
• Synonyms: Polycarbosilane
• Appearance: White to Tan powder

Case Study

Synthesis of Silicon Carbide Nanofibers by Pyrolysis of Polycarbomethylsilane

Qiao, W. M., et al. Applied surface science, 2007, 253(10), 4467-4471.

Researchers achieved high crystallinity silicon carbide (SiC) nanofiber synthesis by pyrolyzing polycarbomethylsilane (PS) coated platelet carbon nanofiber (PCNF) at temperatures exceeding 700 °C while burning PCNF in an oxidative atmosphere. The β-SiC nanofiber obtained through preparation measures less than 100 nm in diameter and presents a surface area of 50 m2/g. As the heat-treatment temperature rises silicon carbide nanofibers become more crystalline with high crystalline SiC nanofibers forming at 1400 °C.
Preparation Procedure of PCNF
The process of adding ammonium bicarbonate to an aqueous solution of iron nitrate produced iron carbonate precipitation. The synthesis of the metal catalyst required calcining iron carbonate at 400 °C with air exposure for four hours before performing reduction in a 10% (v/v) hydrogen/helium atmosphere at 500 ℃ for twenty hours. At 600 ℃ inside a conventional horizontal furnace PCNF emerged from carbon monoxide using the catalyst which underwent a 2-hour pre-treatment in a 10% H2/He mix before introducing the CO/H2 reactant gases.
Preparation Procedure of SiC nanofiber
Dissolved 1 g of polycarbomethylsilane (PS) in 30 ml of hexane using magnetic stirring before introducing 2 g of PCNF into the PS solution and stirring vigorously to achieve dispersion. Evaporation of the solvent produced the PCNF/PS mixture. To create the PCNF/SiC composite, dried the mixture at 80 ℃ for 5 hours in air before subjecting it to heat treatment between 700 to 1400 ℃ for 1 hour at a 10 ℃/min heating rate with 100 ml/min argon flow. The composite underwent calcination in air at 650 ℃ for 2 hours which led to the removal of PCNF from the mixture allowing the isolation of SiC nanofiber.

Synthesis of Carbide-Derived Carbon Fibers via Electrospinning Using Polycarbomethylsilane Precursors

Rose, Marcus, et al. Carbon, 2010, 48(2), 403-407.

The research presented a method to produce highly porous carbide-derived carbon (CDC) fibers by electrospinning polycarbomethylsilane (PCS) and then processing through pyrolysis and chlorination. These ultrafine fibers demonstrate superior properties with a specific surface area reaching 3116 m2 g-1 and a hydrogen storage capacity of 3.86 wt.% at 77 K under a pressure of 17 bar which suggests their use in multiple applications.
CDC Fiber Synthesis Protocol
Electrospinning was performed using PCS with molar weights of 800, 1400, and 3500 g mol-1 dissolved in tetrahydrofuran (THF) without additives. A horizontal electrospinning setup employed a stainless-steel needle (diameter: 0.8 mm) charged at 10 kV DC, positioned 10 cm from a grounded steel target (14 cm diameter) coated with aluminum foil. The solution flow rate was maintained at 4 mL h-1.
Post-electrospinning, fibers were pyrolyzed and chlorinated in a horizontal tube furnace. Fibers were placed in a quartz boat under inert Ar flow (30 min pre-purge) to eliminate oxygen and moisture. Process parameters, including heating rate, final temperature, and duration, varied across five samples (Table 1). Samples 1-4 underwent sequential pyrolysis and chlorination in separate steps, while Sample 5 was chlorinated immediately post-pyrolysis without intermediate cooling or removal. All steps were conducted under continuous Ar or Cl2 flow until furnace cooling.