In this study, the refinement of Multiwalled Carbon Nanotubes (MWCNTs) derived from chemical vapor decomposition is investigated. An ultrasonic pretreatment method is employed to disentangle carbon and metal impurities intertwined with MWCNTs. The pretreated MWCNTs exhibit a marginal decrease in C–O/C = O content from 8.9 to 8.8%, accompanied by a 2.5% increase in sp3 carbon content, indicating a mildly destructive pretreatment approach. Subsequently, selective oxidation by CO2 and hydrochloric acid etching are utilized to selectively remove carbon impurities and residual metal, respectively. The resulting yield of intact MWCNTs is approximately 85.65 wt.%, signifying a 19.91% enhancement in the one-way yield of pristine MWCNTs. Notably, the residual metal content experiences a substantial reduction from 9.95 ± 2.42 wt.% to 1.34 ± 0.06 wt.%, representing a 15.68% increase in the removal rate. These compelling findings highlight the potential of employing a mild purification process for MWCNTs production, demonstrating promising application prospects.

The Spratly Islands dispute is an ongoing territorial dispute between China, Taiwan, Malaysia, the Philippines, Vietnam and Brunei, concerning territorial sovereignty over the Spratly Islands. This conflicting territorial claim between these coastal parties is raising tensions in Asia, so the settlement of this dispute is of key importance for a peaceful atmosphere in the area. The dispute is also significant in respect of being an international geo-strategic, economic, political and legal matter. After a 1988 armed conflict between Vietnamese and Chinese forces, the claimants have looked for approaches to solve the conflict peacefully through different informal endeavors, but due to the complexity of the dispute there are a number of barriers to reaching a permanent settlement. This study puts forward some potential approaches for resolving the dispute, considering its complex nature, by evaluating the six parties’ competing claims and analyzing the legal soundness of their claims.