Comprehensive review of cellulose nanocrystals: preparation, properties, modifications and applications

Abstract Cellulose nanocrystals (CNCs), a class of renewable nanomaterials, offer extraordinary mechanical properties, sustainability, and biocompatibility. This review explores their preparation methods, such as ionic liquids, enzymatic treatment, acid hydrolysis, and TEMPO-mediated oxidation. The unique properties of CNCs, including high crystallinity and surface chemistry, are highlighted. Surface modifications and composite formation extend their applications in industries like packaging, biomedicine, and environmental remediation. This review synthesises recent advancements and emerging trends to promote CNC innovation and sustainable material development. A novel class of nanomaterials, cellulose nanocrystals (CNCs) have captivated a lot of attention because of their extraordinary mechanical qualities, renewability, as well as biocompatibility. This review provides an extensive overview of CNCs, beginning with an investigation of their preparation methods, including the use of ionic liquids, enzymatic treatment, acid hydrolysis, and TEMPO-mediated oxidation. The intrinsic properties of CNCs, such as their high crystallinity, barrier properties, use as a rheology modifier, and surface chemistry, are covered in detail. Surface modifications and composite formation are highlighted as key chemical modifications to improve the functionality and variety of applications of CNCs. The article highlights the wide range of industries that use CNCs, including packaging, food applications, biomedicine, and environmental remediation. This review brings to light the wider implications of CNCs and stimulate further advancement in their implementation and advancement and by synthesising latest research and highlighting emerging trends.