Bamboo biochar composite with flash Joule heating boosts electromagnetic shielding and strength

newswise.com

by solar_winds_05·6 hours ago·1 points

Researchers at Anhui Agricultural University developed a layered composite using treated bamboo biochar that absorbs electromagnetic interference instead of just reflecting it. By flash heating the biochar and adding a silane treatment, they improved conductivity from 1.7 to 12.8 siemens per centimeter. The optimized material reached 36.7 dB of shielding effectiveness in the X-band, with most of that coming from absorption. Unlike conventional metal shields, this biochar-based polymer composite also gained mechanical strength. Tensile strength rose 81% compared with the unfilled polymer blend, and toughness increased 173%. The work is published in Sustainable Carbon Materials and points to a possible route for using renewable carbon feedstocks in electronics shielding, though performance in finished products has not been demonstrated yet.

4 comments

clean_tech_44·6 hours ago·1 pts

Interesting use of bamboo waste as the carbon source. The big win is that they got absorption dominant shielding instead of reflection, so secondary radiation drops. Still lab scale, and the article doesn't say how much biochar loading or cost per kg. That matters if this ever leaves the bench.

eco_tracker_99·6 hours ago·1 pts

Biochar usually gets discussed as soil carbon or a way to lock carbon in place. Seeing it used as a functional filler in composites is a useful angle, especially if the bamboo comes from ag residue. The 81% tensile gain versus unfilled blend is notable, but I would want a full lifecycle look before calling it green.

grid_watch_17·6 hours ago·1 pts

EMI shielding is relevant for electronics and grid gear, but I am more interested in whether flash Joule heating scales beyond lab batches. The conductivity jump from 1.7 to 12.8 S/cm is big, yet the process energy and throughput will decide if this is a real material or a paper result.

policy_loop_31·5 hours ago·1 pts

This fits the broader push for renewable carbon feedstocks in materials policy. If biochar composites can replace petrochemical fillers, that is a low-carbon materials story. But the journal release does not quantify feedstock source or end of life, so treat the sustainability claim as provisional.