Biobased carboxymethyl chitosan-modified black phosphorene (BP-CMC) was prepared through an amidation reaction between amino group functionalized black phosphorene (NH-BP) and CMC. Density functional theory (DTF) express that the adsorption energy between urea and phosphene is −6.28 eV, indicating a strong interaction. The resulting BP-CMC was further applied to reinforce the mechanical, flame-retardant and thermal conductivity performance of honeycomb cellulose nanofiber (CNF) film via vacuum filtration. Cone calorimetry test (CCT) result exhibits that the introduction of 30 wt% BP-CMC significantly promoted the fire safety of CNF. For instance, a 98.41% reduction in smoke production rate (SPR), 92.00 % decline in CO release and a 61.31% decrease in heat release rate (HRR) were observed compared to neat CNF. Furthermore, Thermogravimetric infrared (TG-IR) indicates a significant decrease in the release of flammable gases. Raman spectra verify that the incorporation of 30 wt% BP-CMC improves the graphitization degree of residual chars, thus limiting the transfer of heat and oxygen. The improvement in fire safety is attributed to the formation of an intumescent flame-retardant system, which is rich in carbon source (CMC), acid source (BP) and gas source (amino). Simultaneously, the introduction of 30 wt% BP-CMC into CNF leads to considerable enhancement in thermal conductivity (up to 17.49 %), thermal diffusion (utmost to 43.45 %) and heat capacity (increased by 19.23 %). Moreover, the 30 wt % addition of BP-CMC into CNF possesses excellent mechanical properties with the improvement of toughness (increased by 143.50 %) and tensile strength (increased by 140.90 %). This strategy not only provides a new strategy for functionalizing BP but also upgrades the application potential of BP nanosheets in the fire safety of polymer composite films.

中文翻译：

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一种蜂窝状羧甲基壳聚糖-共价连接NH2-黑磷烯生物基纤维素绿色纳米复合材料，可极大增强防火安全性和导热性

通过氨基功能化黑磷烯（NH-BP）与CMC之间的酰胺化反应制备了生物基羧甲基壳聚糖修饰黑磷烯（BP-CMC）。密度泛函理论（DTF）表明尿素和光菲之间的吸附能为-6.28 eV，表明存在很强的相互作用。所得BP-CMC通过真空过滤进一步应用于增强蜂窝状纤维素纳米纤维（CNF）薄膜的机械、阻燃和导热性能。锥形量热测试（CCT）结果表明，30 wt% BP-CMC 的引入显着提高了 CNF 的防火安全性。例如，与纯 CNF 相比，烟雾产生率 (SPR) 降低了 98.41%，CO 释放量降低了 92.00%，热释放率 (HRR) 降低了 61.31%。此外，热重红外（TG-IR）表明可燃气体的释放显着减少。拉曼光谱证实，30 wt% BP-CMC 的加入提高了残留炭的石墨化程度，从而限制了热量和氧气的传递。消防安全性的提高归功于富含碳源（CMC）、酸源（BP）和气源（氨基）的膨胀型阻燃体系的形成。同时，在 CNF 中引入 30 wt% BP-CMC 导致导热率（高达 17.49 %）、热扩散（最高 43.45 %）和热容（增加 19.23 %）显着增强。此外，在CNF中添加30wt%的BP-CMC具有优异的机械性能，韧性（提高了143.50%）和拉伸强度（提高了140.90%）。该策略不仅为BP功能化提供了新的策略，而且提升了BP纳米片在聚合物复合薄膜防火安全中的应用潜力。