Environmentally benign and biodegradable chitosan (CS) membranes have disadvantages such as low mechanical strength, high brittleness, poor heat resistance and poor water resistance, which limit their applications. In this paper, home-made cellulose nanocrystals (CNC) were added to CS to prepare CNC/CS composite membranes through mechanical mixing and solution casting approaches. The effects of CNC dispersion patterns and CNC contents on the properties of composite membranes were studied. The analysis of the surface and cross-section morphology of the membranes showed that the dispersion performance of the composite membrane was better in the case that CNC was dissolved in an acetic acid solution and then mixed with chitosan by a homogenizer (Method 2). CNC had a great length-diameter ratio and CNC intensely interacted with CS. The mechanical properties of the composite membrane prepared with Method 2 were better. With a CNC content of 3%, the tensile strength of the composite membrane reached 43.0 MPa, 13.2% higher than that of the CNC-free membrane. The elongation at break was 41.6%, 56.4% higher than that of the CNC-free membrane. Thermogravimetric, contact angle and swelling analysis results showed that the addition of CNC could improve the heat and water resistance of the chitosan membrane.

Mechanochromic luminogens are of significant importance in both academic and technical aspects. Thus far, most mechanochromic compounds exhibit bathochromically shifted emission upon grinding; the examples of those that exhibit blue-shifted emission still remain limited. Herein, a donor–acceptor–donor (D–A–D)-structured conjugate, namely 4,7-di(2-thienyl)-2,1,3-benzothiadiazole (DTBT), comprising benzobis(1,2,5-thiadiazole) and thiophene units, has been carefully synthesized and investigated. DTBT exhibits typical intramolecular charge transfer (ICT) characteristics, crystallization-induced phosphorescence (CIP), and remarkable mechanochromism. Although it merely emits fluorescence in solutions with distinct ICT features, its crystals demonstrate bright-red room-temperature phosphorescence (616 nm) with efficiency up to 25.0% and generate yellow excimer fluorescence (578 nm) upon mechanical grinding, accompanying decreased lifetimes from 10.9 μs to 3.5 ns and a blue-shifted emission of 38 nm. These results highly indicate the feasibility to fabricate novel CIP luminogens with blue-shifted mechanochromism.

Dispersion is crucial for many applications of nanostructured materials. In this work, a facile and efficient method for dispersion of cellulose nanocrystals@polyaniline (CNCs@PANI) nanocomposites in an aqueous solution is reported by using cellulose nanofibers (CNFs) as a dispersant. CNCs@PANI was prepared for the experiment by using CNCs as a template and controlling the reactions to obtain fiber-like nanocomposites. Then, the nanocomposite was dispersed in water with the CNFs by means of mechanical shearing. The centrifugal and storage stabilities of the nanocomposite were measured, as well as the zeta potential. The results showed that the CNFs had special dispersion assisting effects for dedoped CNCs@PANI. The CNCs@PANI dispersion showed good centrifugal and storage stability, and a zeta potential of −30.7 mV was recorded with the addition of 10 wt% CNFs. This CNCs@PANI dispersion was cast to obtain a conductive film, which had tensile strength and electrical conductivity of 26.7 MPa and 104.7 S m⁻¹, respectively.

A highly flexible and conductive nanohybrid film based on multi-walled carbon nanotube (MWNT) was prepared using synergistic dispersion effects of nanosisal cellulose and graphene oxide (GO). The dispersion effect of MWNT was characterized using illustrative diagrams of different dispersions after centrifuge, transmission electron microscope, and Zeta potential, respectively. The results showed that 80 wt% MWNT was efficiently dispersed and formed a stable nanodispersion solution using 10 wt% cellulose nanofiber (CNF) and 10 wt% GO as dispersants. The conductivity and tensile strength of the CNF/GO/MWNT nanocomposite film were up to 1818.19 S/m and 25 MPa, respectively.

Two magnetic supports with different morphologies and particle sizes were designed and prepared for cellulase immobilization based on chitosan and industrial by-product magnetic coal fly ash (MCFA). One was prepared by coating chitosan onto spherical MCFA particles to form non-porous MCFA@chitosan gel microcomposites (Support I) with a size of several micrometers, and the other was prepared using the suspension method to form porous MCFA/chitosan gel beads (Support II) with a size of several hundred micrometers. Cellulase was covalent binding to the support by glutaraldehyde activation method. The morphology, structure and magnetic property of immobilized cellulase were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and a vibrating-sample magnetometer. The cellulase loading on Support I was 85.8 mg/g with a relatlvely high activity recovery of 76.6%, but the immobilized cellulase exhibited low thermal stability. The cellulase loading on Support II was 76.8 mg/g with a relative low activity recovery of 51.9%, but the immobilized cellulase showed high thermal stability. Cellulase immobilized on Support I had a glucose productivity of 219.8 mg glucose/g CMC and remained 69.9% of the original after 10 cycles; whereas the glucose productivity was 246.4 mg glucose/g CMC and kept 75.5% of its initial value after 10 repeated uses for Support II immobilized cellulase. The results indicate that the two supports can be used as cheap and effective supports to immobilize enzymes.