Nanomaterials prepared from naturally available biopolymers could potentially be harmless and benign for the ecosystem. Such environmentally biodegradable nanomaterials derived from cellulose, lignin, chitin and starch are hypothesized to support the development of eco-friendly functional nanosystem. In our lab, nanolignin is being extracted from coconut fibers and cotton stalks by microbial process, high shear homogenization or ultrasonication process.
For microbial process, the lignin degrading fungal isolates, Aspergillus nidulans and Aspergillus oryzae are being used. The microbial process yields 58.4% nanolignin while homogenization and ultrasonication processes yield 81.4% and 64.3%, respectively (coconut fiber nanolignin). In case of cotton stalks, microbial process yields 45.3% nanolignin while homogenization and ultrasonication processes yield 79.50% and 62.60%, respectively. Consequently, nanolignin, a value added compound can be extracted from coconut fibers and cotton stalks to be used in textile, biomedical and environmental applications among others.
The application of nanolignin (produced by microbial process) is demonstrated for textile applications. Nanolignin (size: 27.5 nm ± 2.7 nm) applied onto the surface of cotton and linen fabrics by pad-dry-cure method using acrylic binder showed excellent antibacterial (as per AATCC-100 standard method), UV blocking (as per AATCC-186 standard method) and antioxidant (as per DPPH method) properties. Newer application of microbial produced nanolignin for multifunctional finishing of cotton and linen fabrics is demonstrated to generate medical / biomedical textiles.
TEM imgae of Nanolignin