Editorials

Fibers and fillers are important raw materials for the preparation of paper products. Similar to fiber engineering, filler engineering for papermaking has become an active research area. There are similarities as well as differences between engineering involving each of these classes of materials. There are differences in such aspects as the nature of materials to be engineered, applicable engineering methods, and engineerablity of the material surfaces. The co-development of fiber engineering and filler engineering can potentially provide many benefits to the papermaking industry. For filler engineering, the relevant research topics broadly can include fibrous filler engineering, hollow/porous filler engineering, acid-stabilization of calcium carbonate fillers, surface encapsulation of naturally occurring polymers or their derivatives, preflocculation, precoagulation, cationic modification, filler/size hybrid formation, organic filler engineering, using combinations of different types of available fillers, multilayer deposition modification, modification with polymer latexes or dispersants, physical modification, mechanical modification, surface functionalization, fines-filler composite/hybrids or fiber-filler composite/ hybrid formation, in-situ polymerization modification, surface grafting, physical treatment in the presence of polymeric additives, filler precipitation, and core-shell composite filler engineering.

The current state of biorefinery development is focused almost entirely on the production of fuel ethanol. However, an ethanol-centric approach misses the crucial example set by the petrochemical industry. The ability to fractionate a raw material, rather than simply pretreating it, enables the parallel production of low value, high volume fuels and high value, low volume chemicals. By developing analogous fractionation processes for biomass, giving separate process streams of cellulose, hemicellulose and lignin, the biorefining industry will be able to recognize the synergistic advantages of producing both energy and profits.

The papermaking industry can benefit a lot from nanotechnology. This versatile technology can also be used in the area of fillers for papermaking wet end applications. In such applications the main technological examples currently available include wet end addition of commercially available nanofillers, formation of nanofiller/fiber or nanofiller/fibril hybrids, development of novel categories of nanofillers such as high aspect ratio nanofillers, and combination of microfillers with nanostructures by specially controlled routes to obtain composite nanofillers. It is worth noting that there are certain challenges associated with nanofillers, such as high cost, difficulty in structure and performance control, poor dispersability and retention, possible severe negative effects on paper strength, possible detrimental interactions between nanofillers with some wet end additives, and the industry-related limitations. However, in the long run, the research and development in the area of nanofillers will surely create many fruitful results.

Kerala in south India grows several cash crops such as banana and pineapple, the crop residues of which are sources of natural fibres that can be used in hand papermaking. Kerala, however, does not have a tradition in hand papermaking. The following is an account of an attempt to popularize the art and craft of hand papermaking among self-help groups as a means of self-employment and waste utilization, using fibres extracted from agriwaste and local plants.

Articles published in scholarly journals, such as this one, tend to be mainly addressed to researchers at universities. Industrial follow-up and implementation of results from a scholarly article appears to be the exception, rather than the rule. Research grant specifications, as well as university policies, favor the generation of new knowledge, rather than the implementation of good ideas. But without patent protection, corporations have low motivation to expend the considerable effort to reduce ideas to practice after they have been openly published. The author speculates that the situation could be much more dynamic if there were a system of priority of implementation. According to such a system, the first company to successfully implement an idea that first appears in a peer-reviewed journal article, as validated by its debut in the marketplace, would have a grace period during which competitors would have to pay them a fee to sell a generic version of the same thing.

Carbon footprint reduction is a global concern. For the papermaking industry, strategically effective measures of carbon footprint reduction can include many aspects such as energy efficiency improvement, use of renewable carbon-neutral energy, practicing of sustainable forestry, and development of an integrated forest products biorefinery. Filler addition in papermaking can save substantial amounts of pulp fibers, and reduce energy consumption, which can surely contribute to reduction in paper’s carbon footprint. However, the negative effect of filler addition on paper recycling, and the energy consumption associated with the production, processing, and treatment of fillers, will contribute to the carbon footprint. On balance, it can be considered that filler addition in reasonable amounts is likely to lower the paper’s carbon footprint. Certain research work is still needed to better understand the relationship between filler addition and the carbon footprint of papermaking.

Cellulosic ethanol production has drawn much attention in recent years. However, there remain significant technical challenges before such production can be considered as economically feasible at an industrial scale. Among them, the efficient conversion of carbohydrates in lignocellulosic biomass into fermentable sugars is one of the most challenging technical difficulties in cellulosic ethanol production. Use of ionic liquids has opened new avenues to solve this problem by two different pathways. One is pretreatment of lignocellulosic biomass using ionic liquids to increase its enzymatic hydrolysis efficiency. The other is to transform the hydrolysis process of lignocellulosic biomass from a heterogeneous reaction system to a homogeneous one by dissolving it into ionic liquids, thus improving its hydrolysis efficiency.

Wood modification is a generic term describing the application of chemical, physical, or biological methods to alter the properties of the material. The aim is to get better performance from the wood, resulting in improvements in dimensional stability, decay resistance, weathering resistance, etc. It is essential that the modified wood is non-toxic in service and that disposal at the end of life does not result in the generation of any toxic residues. Over the past five years there have been significant developments in wood modification technologies, especially in the commercial sector. This technology is here to stay.

The influence of cross-linking and branching on the number of interconnections between lignin units and the number of end groups (phenolic and non-phenolic) in the lignin molecules is discussed. Branching results in an increased number of end groups. It appears from an evaluation of the literature that p-hydroxyphenylpropane units are phenolic to a larger extent than guaiacylpropane units and that such units in turn are phenolic to a larger extent than syringylpropane units. It is proposed that this is related to the relative oxidation potentials of the lignin units. Guaiacylpropane units C-substituted in the 6-position are phenolic to a large extent. Alternative explanations for this are presented.

Bio-monitoring of air quality in TehranCity was investigated by analyzing 36 pine tree (Pinus eldarica Medw.) barks. The samples were taken from different locations with different degrees of metal pollution (urban, industrial, highway, and control sites). Then, the concentrations of lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), and chromium (Cr) were measured using a flame atomic absorption spectrophotometer. The results of this study showed that the highest and lowest metal concentrations were found in the heavy traffic sites and the control site, respectively. Lead content was found to be the highest in high traffic density areas. The industrial part of the city was characterized by high Zn, Cr, and Ni contents. Variation in heavy metal concentrations between sites was observed and attributed to differences in traffic density and anthropogenic activities. The research also confirms the suitability of Pinus eldarica Medw barks as a suitable bio-indicator of aerial fallout of heavy metals.