关键词: 氮化硼, 纳米纤维素, 棉织物改性, 导热性能, 凉感织物

Abstract: As global warming intensifies and summer temperatures rise, people's demand for comfort and coolness in summer clothing has been increasing year by year. However, the cool feeling performance, breathability and comfort of existing textiles on the market is generally poor. Traditional cotton fabrics, while excellent in moisture absorption and breathability and suitable for summer wear, have a low thermal conductivity, resulting in poor cool feeling performance when used alone. This makes it difficult to meet people's demand for a cool sensation in high-temperature environments. Hence, the research and development of cotton fabrics with cool feeling function holds broad prospects. 
To develop cotton fabrics with a cool feeling effect, one approach is to introduce high thermal conductivity fillers to construct thermal conduction pathways, so as to enhance the overall thermal conductivity of the cotton fabric to achieve the desired coolness. In our study, functional BN (FBN) was synthesized using an ultrasonic-assisted liquid-phase exfoliation method, and further functionalized with nanofibrillated cellulose (NFC). FBN/nanofibrillated cellulose (NFC) solutions were prepared by blending different concentrations of FBN powder with a uniform dispersion of NFC. Meanwhile, h-BN solutions of the same concentrations were prepared as control experiments. The two prepared boron nitride solutions were then applied to cotton fabrics through a double-dip and double-nip process, followed by heat-setting at 120℃ for 90 seconds, ultimately yielding two types of modified cotton fabrics with boron nitride solutions. After comparing the thermal conductivity, cool feeling performance, mechanical properties, and other properties of the original cotton fabric, h-BN modified cotton fabrics, and FBN/NFC modified cotton fabrics, it was found that the FBN/NFC modified cotton fabric prepared under this process had an in-plane thermal conductivity of 6.93 W/(m·K), approximately 3.96 times higher than that of the original cotton fabric. Through finite element simulations of their heat transfer process, the FBN/NFC modified cotton fabric exhibited higher heat flux vectors and a broader temperature distribution, indicating its enhanced heat transfer capability. The cool feeling coefficient of the FBN/NFC modified cotton fabric was 0.27 J/(cm²·s), exceeding the national standard and aligning with the trend of increased thermal conductivity. This indicated that the cotton fabrics modified by FBN/NFC solution could effectively transfer human heat, accelerate the rate of heat dissipation, and bring a cool and comfortable feeling to the human body. After modification with FBN/NFC solution, the hydrophilicity of cotton fabrics was enhanced, while its breathability slightly decreased. Additionally, the modification with the FBN/NFC solution had minimal impact on the mechanical properties of the cotton fabric, which remained high-strength and low-elongation after modification. 
The above results indicate that the cotton fabric, after being treated with a 10% mass fraction FBN/NFC solution through a double dipping and double nipping process, followed by heat-setting at 120℃ for 90 seconds, exhibits significant improvements in both thermal conductivity and cool feeling coefficient compared to the original cotton fabric. FBN/NFC modified cotton fabrics can be practically applied as cool feeling textiles for personal heat management and this offers certain guiding significance for the design of cool feeling textiles.

Key words: boron nitride, nanofibrillated cellulose, cotton fabric modification, thermal conductivity, cool feeling fabrics