This study aimed to develop eco-friendly multifunctional nanocellulose (NC) hybrid films with tailored properties for versatile applications including packaging and photovoltaics. Hybrid films composed by cellulose nanocrystals (CNC) and carboxymethylated cellulose nanofibrils (CNF) were produced at various mass ratio (CNC - 100:0 to 0:100). Montmorillonite clay (MTM) was incorporated (50 % by mass) into the CNC:CNF films. CNC-only films easily dispersed in water, but by adding CNF or MTM, the structural integrity was enhanced. Films with ≥50 % CNF and MTM had a strength reduction of 9-35 % and increased brittleness. The hybrid films presented transmittance above 60 % and haze varying from 5 % to 60 % at 550 nm which can be a beneficial for light management. All films kept color stability over 1000 h of artificial sunlight, a critical packaging feature for long-term storage. CNC: CNF films without MTM showed better potential for optoelectronic applications due to higher transmittance and smoother surfaces, while those with MTM presented UV protection (up to 250 nm) and swelling resistance (28-53 %) which could also benefit optoelectronics increasing their lifespan. Balancing the hybrid films composition is key for optoelectronics, while packaging applications tolerate broader compositions. These findings demonstrate the versatility of NC hybrid films in creating sustainable materials for diverse applications.

Paper was pre-calendered in a pilot scale configuration with a traditional soft nip calender and a metal belt calender. All calendering strategies reduced surface roughness and permeability of the samples, but different strategies affected the surface roughness and permeability differently. Six test points from the pilot calendered papers were chosen for laboratory coating studies. Uncalendered paper was included as reference samples. The calendered samples and the reference were pre-coated with a regular pigmented coating consisting of a GCC pigment and a SA latex. Both uncoated and pre-coated substates were barrier coated with a PVOH solution in one and two layers. The coating pick up was determined gravimetrically and the barrier properties were evaluated with TAPPI T454 grease resistance tests.

Paper was pre-calendered in a pilot scale configuration with a traditional soft nip calender and a metal belt calender. All calendering strategies reduced surface roughness and permeability of the samples, but dif-ferent strategies affected the surface roughness and permeability differently. The metal belt calender seemed to have a larger effect on the large-scale variations compared to the soft nip calender.Six test points from the pilot calendered papers were chosen for laboratory coating studies. Uncalendered paper was included as reference samples. The calendered samples and the reference were pre-coated with a regular pig-mented coating consisting of a ground calcium carbonate (GCC) pigment and a styrene acrylate (SA) latex. Both uncoated and pre-coated substrates were barrier coated with a polyvinyl alcohol (PVOH) in one and two layers. The coating pickup was determined gravimetrically, and the barrier properties were evaluated with TAPPI Standard Test Method T 454 grease resistance test.All samples needed two PVOH coating layers to form a grease barrier. The uncalendered sheets showed the best results with one coating layer, but this was at the expense of a higher coating pickup compared to the calendered sheets. The barrier coating pickup could be reduced by a combination of high temperature metal belt calendering and pre-coating. The high temperature and long residence time in the nip enabled plasticization of the fibers. This led to an irreversible deformation, even after water application. This meant that the smoothness obtained during cal-endering would be less affected by water-induced roughening during the coating operation.Application: Most works on barrier research have previously focused on either coating formulations or coating processes. This work complements earlier research by demonstrating that the amount of required coating color can be reduced through an appropriate calendering strategy and use of pre-coating.

Paper was pre-calendered in a pilot scale configuration with a traditional soft nip calender and a metal belt calender. All calendering strategies reduced surface roughness and permeability of the samples, but dif-ferent strategies affected the surface roughness and permeability differently. The metal belt calender seemed to have a larger effect on the large-scale variations compared to the soft nip calender.Six test points from the pilot calendered papers were chosen for laboratory coating studies. Uncalendered paper was included as reference samples. The calendered samples and the reference were pre-coated with a regular pig-mented coating consisting of a ground calcium carbonate (GCC) pigment and a styrene acrylate (SA) latex. Both uncoated and pre-coated substrates were barrier coated with a polyvinyl alcohol (PVOH) in one and two layers. The coating pickup was determined gravimetrically, and the barrier properties were evaluated with TAPPI Standard Test Method T 454 grease resistance test.All samples needed two PVOH coating layers to form a grease barrier. The uncalendered sheets showed the best results with one coating layer, but this was at the expense of a higher coating pickup compared to the calendered sheets. The barrier coating pickup could be reduced by a combination of high temperature metal belt calendering and pre-coating. The high temperature and long residence time in the nip enabled plasticization of the fibers. This led to an irreversible deformation, even after water application. This meant that the smoothness obtained during cal-endering would be less affected by water-induced roughening during the coating operation.Application: Most works on barrier research have previously focused on either coating formulations or coating processes. This work complements earlier research by demonstrating that the amount of required coating color can be reduced through an appropriate calendering strategy and use of pre-coating.

A hemicellulose-based barrier formulation was produced from wood chips to pilot coating application in a bladecoater. The development process is described from a project planning point of view with network plan and decisionpoints.Different hemicelluloses were produced and compared in the research laboratory. Oxygen barrier properties fromfilms and rheology of water suspensions were evaluated for different laboratory produced hemicelluloses originatingfrom wood chips or from kraft pulps. The viscosity at low and high shear rates were evaluated. From these results,hemicellulose produced from birch wood chips was chosen.Hemicellulose was then produced at in kg quantities. The hemicellulose was produced employing pre-hydrolysistreatment of birch wood chips. The concentration of hemicellulose pre-hydrolyses was increased from 3.3% to11.5% by membrane filtration. The barrier properties of the hemicellulose coated material were evaluated inlaboratory scale. A pre-coating was also evaluated in laboratory scale.Trials were performed at Iggesund PaperBoard in their pilot scale coater. A pre-coating was applied during the firstday, and the hemicellulose-based coating was applied on the second day. The pilot trials went well without anylarger obstacles. Quick barrier evaluations showed that the hemicellulose-based barrier coating had a good greaseresistance even if the coating consumption during the trials indicated a low application grammage.

This article describes nanocomposite films with separately grown protein nanofibrils (PNFs) in a nonfibrillar protein matrix from the same protein starting material (whey). Tensile tests on the glycerol-plasticized films indicate an increased elastic modulus and a decreased extensibility with increasing content of PNFs, although the films are still ductile at the maximum PNF content (15 wt %). Infrared spectroscopy confirms that the strongly hydrogen-bonded β-sheets in the PNFs are retained in the composites. The films appear with a PNF-induced undulated upper surface. It is shown that micrometer-scale spatial variations in the glycerol distribution are not the cause of these undulations. Instead, the undulations seem to be a feature of the PNF material itself. It was also shown that, apart from plasticizing the protein film, the presence of glycerol seemed to favor to some extent exfoliation of stacked β-sheets in the proteins, as revealed by X-ray diffraction.

Phosphate functionalized nanofibrillated cellulose (NFC) was produced through an industrially attractive process, by reacting wood pulp with a phosphate containing salt, followed by mechanical delamination through microfluidization. The degrees of delamination of the phosphorylated NFCs (judged by among others AFM-imaging, rheological studies and tensile strength measurements on NFC films) were found to improve with increasing functionalization of the pulp and number of microfluidization-passes. The NFC systems were found to display similar characteristics as other well-known NFC systems. Interestingly, however, the sufficiently delaminated phosphorylated NFCs exhibited significantly lower oxygen permeability values (at RH 50%) than the published values of several well-known highly delaminated NFC systems. The potential application of the phosphorylated NFC in packaging applications can hence be envisaged.