Construction, characterization, properties and multifunctional applications of stimuli-responsive shape memory polymeric nanoarchitectures:a review

Due to the advent of nanotechnology, deficiencies and limitations inherent in stimuli-responsive shape memory polymeric matrices (SMP), have been effectively mitigated, through the inclusion of a versatile range of organic or inorganic nanoparticulates within the confines of SMP matrice/s. This phenomenon has resulted in the emergence of shape-memory polymeric nanoarchitectures (SMPNs) possessing enhanced and outstanding properties, when compared with the pristine SMP, and this has subsequently enlarged their scope of applications (civil engineering, biomedical gadgets, aerospace, bionics engineering, energy, electronic engineering, household products, and textile engineering). Furthermore, SMPNs enhances athermal stimuli-activities including electroactivity, magneto-activity, water-activity, and photo-activity, as well as shape memory effect (SME) including multiple-shape memory effect (MSME), spatial shape memory effect (SSME), as well as dual-route shape memory effect (DRSME). This elucidation is essential and imperative at this time to enlighten the polymeric universe on new advancements in fabrication, features and applications of stimuli responsive SMPNs. Therefore, this paper, presents, very recently emerging advancements, in construction, characterization, properties and multifunctional applications of stimuli-responsive SMPNs with special emphasis on carbon nanotubes (CNT), carbon nanofibers (CNF), cellulose nanocrystals, and nanoclay reinforced SMPNs.</p

Physical, chemical and mechanical properties of corn sheath as pulp and paper raw material

Most papers are made from virgin wood-based pulp of hardwood sources but recently, softwood have received enormous attention as alternative to hard wood because the hardwood takes a significant number of years to mature enough for use in the pulp and paper industry unlike softwood which are majorly annual plants. The annual crop in focus in this work is the yellow open-pollinated variety of corn which generates tons of waste at harvest. A novel attempt is made to ascertain the viability of corn sheaths as raw material for the pulp and paper industry by carrying out a comprehensive analysis on the pulp and paper made from the pulp. The sheaths were dried, shred and cut into pieces suitable for the digester and the pulps obtained were analysed for physicochemical properties. Hand sheets were also made using the generated pulp and its physico-mechanical properties were analysed. Results obtained were compared with pulp from corn husks from other parts of the country, three Nigerian fibre sources – silk cotton, bagasse and rice straw and other foreign non-wood sources and found to be of competitive properties. Pulp properties of Lignin content, ash content, cellulose, hot and cold water solubility of the fibres were 13.72 ± 1.21%, 1.27 ± 0.23%, 53.26 ± 1.11%, 15.20 ± 2.11 and 6.14 ± 2.43 respectively while the mechanical properties of paper from the pulp were Bursting strength (282.163 KPa m2/g), Tear strength (146.119), Tensile strength (257.6N/m) and Tensile Index (3.9Nm/g). It was found that in all properties, the corn sheath was better than the rice straw fibers but not as good as the silk cotton and bagasse fibers. However, the corn sheath has been identified, as a viable raw material for the pulp and paper industry in Nigeria