The difference between cellulose nanofiber filaments and cellulose nanocrystals

Cellulose Nanofibers (CNF) and Cellulose Nanocrystals (CNC) are both nanoscale derivatives of cellulose, but they have some significant differences in structure, properties and applications. Here are the main differences between them:

1. Structure and form

1. Cellulose nanofiber filaments (CNF)

oStructure : Cellulose nanofibers are long fibrous nanomaterials composed of cellulose molecular chains Its structure is usually relatively flexible and long, showing a higher aspect ratio (the ratio of length to diameter)..

oModel : CNF usually exists in fibrous shape , with a diameter ranging from several nanometers to tens of nanometers, and a length of up to several micrometers to tens of micrometers.

2. Cellulose nanocrystals (CNC)

oStructure : Cellulose nanocrystals are cellulose nanocrystals obtained by acid hydrolysis, and their structure is more crystallized They are mainly composed of highly crystalline cellulose segments, showing strong rigidity..

oModel : CNCs usually appear in short rods, needles or cubes, with diameters ranging from a few nanometers to a dozen nanometers, and lengths usually range from tens to hundreds of nanometers.

2. Preparation method

1. Cellulose nanofiber filaments (CNF)

o Preparation method : Commonly used preparation methods include mechanical fibrosis, enzymatic lysis, acid lysis, etc. Mechanical fibrosis breaks the cellulose raw material through high shear force to form nano-scale fibers; enzymatic method uses specific enzymes to hydrolyze the cellulose; acid-lysis method uses acid treatment to partially hydrolyze the cellulose to obtain cellulose nano-fiber filaments.

2. Cellulose nanocrystals (CNC)

o Preparation method : Cellulose nanocrystals are usually extracted by acid hydrolysis (such as sulfuric acid hydrolysis). The acid hydrolysis process removes the non-crystalline part and only retains highly crystalline cellulose areas to form nanoscale cellulose crystals.

III. Physical and chemical properties

1. Cellulose nanofiber filaments (CNF)

oStrength vs. Rigidity : CNF usually exhibits higher flexibility and lower rigidity. They have a high specific surface area, providing good mechanical strength and flexibility.

oSurface properties : Due to the longer fiber structure, CNF has rich surface functional groups, which can effectively modify and functionalize interfaces with other materials.

2. Cellulose nanocrystals (CNC)

oStrength and rigidity : CNC has high rigidity and strength, showing a high elastic modulus. Their crystallization regions impart high mechanical strength.

oSurface properties : The surface of CNC is mainly a highly crystalline cellulose region and further chemical modifications are often required to improve its compatibility with other materials.

IV. Application fields

1. Cellulose nanofiber filaments (CNF)

oApplication areas : mainly used for reinforcement of composite materials (such as paper, plastics), biomedicine (such as drug delivery systems), water treatment (such as filter membranes), food additives, etc. The high specific surface area and good flexibility of CNF make it widely used in these fields.

2. Cellulose nanocrystals (CNC)

oApplication areas : Mainly used to develop high-strength composite materials (such as reinforced plastics, coatings), optical materials (such as optical transparent materials), sensors, colloid stabilizers, etc. The high rigidity and crystallinity of CNCs give them specific advantages in these fields.

Summarize

Cellulose nanofiber filaments (CNF) and cellulose nanocrystals (CNC) are both nano-scale cellulose derivatives with excellent properties, but their structure, physicochemical properties and application fields vary. The selection of the appropriate nanocellulose type needs to be determined based on the specific application requirements and target performance.