Cellulose Polymer Research Articles

Hydroxypropyl Cellulose Polymers as Efficient Emulsion Stabilizers: The Effect of Molecular Weight and Overlap Concentration

Hydroxypropyl cellulose (HPC) is a non-digestible water-soluble polysaccharide used in various food, cosmetic, and pharmaceutical applications. In the current study, the aqueous solutions of six HPC grades, with molecular mass ranging from 40 to 870 kDa, were characterized with respect to their precipitation temperatures, interfacial tensions (IFTs), rheological properties and emulsifying and stabilization ability in palm (PO) and sunflower (SFO) oil emulsions. The main conclusions from the obtained results are as follows: (1) Emulsion drop size follows a master curve as a function of HPC concentration for all studied polymers, indicating that polymer molecular mass and solution viscosity have a secondary effect, while the primary effect is the fraction of surface-active molecules, estimated to be around 1–2% for all polymers. (2) Stable emulsions were obtained only with HPC polymers with Mw ≥ 400 kDa at concentrations approximately 3.5 times higher than the critical overlap concentration, c*. At PO concentrations beyond 40 wt. % or when the temperature was 25 °C, these emulsions appeared as highly viscous liquids or non-flowing gels. (3) HPC polymers with Mw < 90 kDa were unable to form stable emulsions, as the surface-active molecules cannot provide steric stabilization even at c ≳ 4–5 c*, resulting in drop creaming and coalescence during storage.

Revolutionizing photocatalysis: Synthesis of innovative poly(N-tertiary-butylacrylamide)-graft-hydroxypropyl cellulose polymers for thermo-responsive applications via metal-free organic photoredox catalysis.

In this study, we present a groundbreaking approach utilizing metal-free, visible light-mediated organic photoredox catalyzed atom transfer radical polymerization (O-ATRP) to synthesize cellulose-based stimuli-responsive polymers. Our method resulted in the successful synthesis of innovative metal-free poly(N-tertiary-butylacrylamide)-graft-hydroxypropyl cellulose (PNTBAM-g-HPC) polymers with exceptional control over molecular weight and narrow dispersity index (Đ) and explored their applications in organo-photocatalytic reactions. This approach addresses the limitations of traditional atom transfer radical polymerization method, which suffer from metal contamination and toxicity related problems. O-ATRP and organic photoredox catalysts have been sought to address these difficult challenges. In this study, we synthesized organic compound; 2,4,5,6-tetrakis(diphenylamino)isophthalonitrile (4DPIPN), which served as an organic photoredox catalyst, enabling the synthesis and application study of PNTBAM-g-HPC polymers via organic photoredox catalysis. Furthermore, by employing 4DPIPN, three different types of PNTBAM-g-HPC polymers were synthesized. Through thorough characterization techniques including FTIR, NMR, UV/Visible spectroscopy, TGA, and GPC analysis, we confirmed the successful synthesis of photocatalyst and three different types of PNTBAM-g-HPC polymers under O-ATRP conditions. By adjusting the molar ratios of PNTBAM side chains, we fine-tuned the LCST of HTA-20 polymers to 37.3°C, demonstrating their thermoresponsive behavior. This synthetic approach shows great potential for applications in biosensors, pharmaceuticals, biomedical engineering, and drug delivery systems.

PVA/CMC‐Ag Polymer Blend Nanocomposites Prepared by Doping Bio‐Derived Ag Nanoparticles and Their Structural, Thermal, Optical, Antimicrobial, and Electrical Characterization

ABSTRACTThis work reports the influence of bio‐derived silver (Ag) nanoparticles insertion on the properties of polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) polymer blend prepared by solution casting method. X‐ray diffraction studies reveal the dispersion of silver nanoparticles into polymer blend matrices. Thermal studies by DSC and TGA indicate the increased thermal stability of the polymer blend due to the addition of bio‐derived silver nanoparticles. Three different steps of weight loss shown by dTGA curves indicate the loss of water adsorbed, elimination of side chains, and the decomposition of the main chain. The maximum degradation of the pure sample occurred at a peak temperature of around 252°C with 65% of degradation, whereas the maximum degradation of the doped samples occurred at a peak temperature of around 322°C with 26% of degradation, which evidences the increased thermal stability of the doped sample. UV–visible spectral analysis shows a decrease in both direct and indirect band gap values with increasing dopant concentration in the polymer blend host, which is an indication of the formation of complexes between the polymer blend and the filler. The antifungal properties of PVA/CMC/Ag blend films are evaluated against four distinct fungus strains. The findings indicate that the activity index increased with the amount of Ag nanoparticles filled in. According to the study, doping PVA/CMC with Ag nanoparticles increases its antimicrobial efficacy. Since these nanocomposites have both electrical conductivity and antimicrobial properties, they may be suggested for future investigation in biomedical applications, including wound dressing and infection prevention.

Variations in carbohydrates molar mass distribution during chemical degradation and consequences on fibre strength

Abstract Industrial oxygen-delignified and fully-bleached hardwood kraft pulps were treated with chemicals to provoke carbohydrates depolymerisation: ozone, hypochlorous acid, and cellulase. The degrees of polymerisation (DP) of cellulose obtained by pulp viscosity measurement in Cuen and by size-exclusion chromatography after direct dissolution in DMAc/LiCl indicated the extent of the chemical degradation inflicted to the fibres. Molar mass distributions (MMD) described the carbohydrates depolymerisation patterns. Fibre strength was assessed by measuring the zero-span tensile index at never-dried state. Fibre strength deterioration seemed to be mainly driven by the topochemistry of the cellulose degradation (homogeneous or localised), rather than by its intensity usually measured as an average DP loss. In fact, depolymerisation by cellulase was found critically detrimental to fibres strength whereas ozone and hypochlorous acid induced little harm to the fibres despite a significant cellulose depolymerisation. According to these results, in line with several past studies, fibre strength measurements should be performed systematically as the sole pulp viscosity is an inadequate indicator. Alternatively, albeit being insufficient strength predictors on their own MMD can give valuable insight on the topochemistry of the cellulose degradation, a key aspect when monitoring fibre strength preservation during pulping and bleaching.

Enhancing thermal stability and viscosity of cellulose ether using propylene carbonate as a transesterification agent for oilfield applications

This study presents the utilisation of Propylene Carbonate (PC), along with an alkali-based solution, to modify the Hydroxyethyl Methyl Cellulose (HEMC) polymer to mitigate the thermal degradation of cellulose ether. The experimental results from FTIR and XRD analysis confirmed the addition of a new function group to the HEMC backbone and the formation of a new organic carbonate-based cellulose ether. Shear viscosity experiments were conducted at concentrations of 0.50-wt.% to 2-wt.% at ambient and elevated temperatures ranging from 80°C-110°C using a rheometer. All polymeric solutions exhibited shear-thinning behaviour, and the viscosity of polymeric solutions was enhanced by increasing the concentration of modified HEMC solutions. The modified HEMC solutions exhibited higher viscosity at 1000 s-1 shear rate at 110ºC compared to the native HEMC solutions, confirming the enhanced thermal stability of the PC-based modified HEMC solution. Alkali-based modified HEMC solution exhibited low shear viscosity at ambient temperature. The alkali-based polymeric solution’s viscosity was increased by 48% at a high shear rate at 110ºC. In conclusion, 0.50-wt.% and 01-wt.% concentration of alkali-based PC-modified HEMC solution proved efficient in maintaining viscosity under ambient conditions, increasing solubility and exhibiting improved thermal stability at geothermal conditions for oil field applications.

Fabrication of Antimicrobial Nickel‐Based Polymerized Cellulose Nanofibers: A Highly Flexible, Conductive, and Biocompatible Membrane for Potential Application in Wearable Devices

Fabrication of Antimicrobial Nickel‐Based Polymerized Cellulose Nanofibers: A Highly Flexible, Conductive, and Biocompatible Membrane for Potential Application in Wearable Devices

A new species and new records of dung-associated bolbitiaceous fungi (Bolbitiaceae, Basidiomycota) from Uruguay

Coprophilous basidiomycetous fungi constitute a distinct ecological group, essential for the recycling of cellulose and other polymers digested by herbivores, and exhibiting adaptations such as thick-walled basidiospores. The family Bolbitiaceae, including the genera Pholiotina, Conocybe and Bolbitius, is well-represented on animal dung. Nonetheless, the coprophilous fungal diversity of Uruguay remains largely unexplored. This study aims to expand the knowledge of Uruguayan coprophilous fungi through the analysis of basidiomes collected from horse and cow dung samples, and using morphological, chemical and multilocus phylogenetic analyses (including ITS, LSU and Tef1-α regions). We recorded and characterized Pholiotina coprophila and Conocybe rufostipes for the first time in Uruguay and also identified and described a new species: Conocybe pruinosa sp. nov. Based on previous reports for related species, we searched for psychoactive tryptamines, but none of the samples in this study showed detectable concentrations of psilocybin or psilocin. Interestingly, in all cases, the clades consisted of sequences from Asia, Europe, North America and now Uruguay, which may correlate with the introduction of bovine cattle from these regions into the country.

Biomimetic Natural Biomaterial Nanocomposite Scaffolds: A Rising Prospect for Bone Replacement.

Biomimetic natural biomaterial (BNBM) nanocomposite scaffolds for bone replacement can reduce the rate of implant failure and the associated risks of post-surgical complications for patients. Traditional bone implants, like allografts, and autografts, have limitations, such as donor site morbidity and potential patient inflammation. Over two million bone transplant procedures are performed yearly, and success varies depending on the material used. This emphasizes the importance of developing new biomaterials for bone replacement. Innovative BNBM nanocomposites for modern bone fabrication can promote the colonization of the desired cellular components and provide the necessary mechanical properties. Recent studies have highlighted the advantages of BNBM nanocomposites for bone replacement; therefore, this review focuses on the application of cellulose, chitosan, alginates, collagen, hyaluronic acid, and synthetic polymers enhanced with nanoparticles for the fabrication of nanocomposite scaffolds used in bone regeneration and replacement. This work outlines the most up-to-date overview and perspectives of selected promising BNBM nanocomposites for bone replacement that could be used for scaffold fabrication and replace other biomorphic materials such as metallics, ceramics, and synthetic polymers in the future. In summary, the concluding remarks highlight the advantages and disadvantages of BNBM nanocomposites, prospects, and future directions for bone tissue regeneration and replacement.

Thermomechanical and Morphological Characteristics of Cellulosic Natural Fibers and Polymer based Composites: A Review

Thermomechanical and Morphological Characteristics of Cellulosic Natural Fibers and Polymer based Composites: A Review

Integrated System of Reverse Osmosis and Forward Pressure-Assisted Osmosis from ZrO2 Base Polymer Membranes for Desalination Technology

In this work, reverse osmosis and forward osmosis membranes were prepared using base cellulosic polymers with ZrO2. The prepared membranes were rolled on the spiral-wound configuration module. The modules were tested on a pilot unit to investigate the efficiency of the RO membrane and the hydraulic pressure effect on both sides of the FO membranes. The RO membrane provided a rejection of 99% for the seawater desalination, and the brine was used as a draw solution for the FO system. First, seawater was used as a draw solution to indicate the best hydraulic pressure, where the best one was 3 bar for the draw solution side, and 2 bar for the feed side, where the water flux reached 48.89 L/m2·h (LMH) with a dilution percentage of 80% and a low salt reverse flux of 0.128 g/m2·h (gMH) after 5 h of operation time. The integrated system of RO and forward-assisted osmosis (PAO) was investigated using river water as a feed and RO brine as a draw solute, where the results of PAO indicate a high-water flux of 68.6 LMH with a dilution of 93.2% and a salt reverse flux of 0.18 gMH. Therefore, using PAO improves the performance of the system.

Research on the Structure and Properties of Traditional Handmade Bamboo Paper During the Aging Process.

Handmade papers, as carriers of paper-based cultural relics, have played a crucial role in the development of human culture, knowledge, and civilization. Understanding the intricate relationship between the structural properties and degradation mechanisms of handmade papers is essential for the conservation of historical documents. In this work, an artificial dry-heat-accelerated aging method was used to investigate the interplay among the mechanical properties of paper, the degree of polymerization (DP) of cellulose, the chemical composition, the hydrogen bond strength, the crystallinity, and the degree of hornification for paper fibers. The results demonstrated for the first time that the mechanical properties of handmade bamboo paper exhibited an initial plateau region, a rapid decline region, and sometimes a second plateau region as it undergoes a dry-heat aging process. The changes in cellulose, hemicellulose, and lignin content were tracked throughout these three stages. The lignin content was relatively stable, while the cellulose and hemicellulose content decreased, which was consistent with the observed decline in mechanical properties. When the DP of cellulose decreased to the range of 600-400, there was a critical point in the mechanical properties of the paper, marking a transition from the initial stable region to a rapid decline region. The fiber embrittlement caused by cellulose chain breakage resulting from the decrease in DP was counteracted by the enhancement of intermolecular hydrogen bonds and the hornification process. A second stable region appeared when the DP was less than 400, marking a transition from a balanced or slightly decreasing trend in the initial plateau region to a sharp decline. This study also discussed for the first time that the formation of the second plateau region may be due to the presence of hemicellulose and lignin, which hinder the further aggregation of cellulose and maintain the structural stability of the fiber cell. The findings of this study can provide guidance for improving ancient book preservation strategies. On the one hand, understanding how these components affect the durability of paper can help us better predict and slow down the aging of ancient books. On the other hand, specific chemical treatment methods can be designed to stabilize these components and reduce their degradation rate under adverse environmental conditions.

Study on the effect of degree of polymerization of cellulose on syngas composition based on established higher heating value prediction model

Study on the effect of degree of polymerization of cellulose on syngas composition based on established higher heating value prediction model

Interfacial functionalization and capillary force welding of enhanced silver nanowire-cellulose nanofiber composite electrodes for electroluminescent devices.

The development of flexible, intelligent, and lightweight optoelectronic devices based on flexible transparent conductive electrodes (FTCEs) utilizing silver nanowires (AgNWs) has garnered increasing attention. However, achieving low surface resistance, strong adhesion to the flexible substrate, low surface roughness, and green degradability remains a challenge. Here, a composite electrode combining natural polymer cellulose nanofibers (TCNFs) with AgNWs was prepared. This process includes non-covalent interface embedding between TCNFs and AgNWs as well as a strong capillary force between the hydrophilic TCNF substrate and AgNWs during water mist capillary force cold welding. By adding ethanolamine and employing a rapid water mist wetting-drying process (within 10 s), the performance of TCNF/AgNW FTCEs significantly improves with reduced sheet resistance (8.3 Ω sq.-1), high light transmission (84.9 %), and low surface roughness (9.9 nm). Additionally, the composite electrode exhibits excellent stability and durability under various conditions such as bending, adhesion, and tensile stress. The prepared flexible electroluminescent device achieves high luminous intensity (43.6 cd m-2) and excellent operational stability, thanks to the outstanding performance of the composite electrode. This study presents a simple strategy for fabricating FTCEs using nanocellulose combined with AgNWs offering a potential material option for key components in green flexible optoelectronic devices.

Distinct lignocelluloses of plant evolution are optimally selective for complete biomass saccharification and upgrading Cd2+/Pb2+ and dye adsorption via desired biosorbent assembly

In this study, 15 plant species representing plant evolution were selected, and distinct lignocellulose compositions for largely varied biomass enzymatic saccharification were detected. By comparison, the acid-pretreated lignocellulose of rice mutant was of the highest Congo-red adsorption (298 mg/g) accounting for cellulose accessibility, leading to complete cellulose hydrolysis and high bioethanol production. By conducting oxidative-catalysis with the acid-pretreated lignocellulose of moss plant, the optimal biosorbent was generated with maximum Cd/Pb adsorption (54/118 mg/g), mainly due to half-reduced cellulose polymerization degree and raised functional groups accountable for multiple physical and chemical interactions. Furthermore, the acid-pretreated lignocellulose of eucalyptus was of large and small pores for much higher adsorption capacities with direct-yellow and direct-blue than those of the previously-reported. Therefore, this study raises a mechanism model about how distinct lignocelluloses of plant evolution are selective for complete biomass saccharification and optimal biosorbents assembly, providing insights into lignocellulose biosynthesis and biomass conversion.

Second-Sphere Histidine Catalytic Function in a Fungal Polysaccharide Monooxygenase.

Fungal polysaccharide monooxygenases (PMOs) oxidatively degrade cellulose and other carbohydrate polymers via a mononuclear copper active site using either O2 or H2O2 as a cosubstrate. Cellulose-active fungal PMOs in the auxiliary activity 9 (AA9) family have a conserved second-sphere hydrogen-bonding network consisting of histidine, glutamine, and tyrosine residues. The second-sphere histidine has been hypothesized to play a role in proton transfer in the O2-dependent PMO reaction. Here the role of the second-sphere histidine (H157) in an AA9 PMO, MtPMO9E, was investigated. This PMO is active on soluble cello-oligosaccharides such as cellohexaose (Glc6), thus enabling kinetic analysis with the point variants H157A and H157Q. The variants appeared to fold similarly to the wild-type (WT) enzyme and yet exhibited weaker affinity toward Glc6 than WT (WT KD = 20 ± 3 μM). The variants had comparable oxidase (O2 reduction to H2O2) activity to WT at all pH values tested. Using O2 as a cosubstrate, the variants were less active for Glc6 hydroxylation than WT, with H157A being the least active. Similarly, H157Q was competent for Glc6 hydroxylation with H2O2, but H157A was less active. Comparison of the crystal structures of H157Q and WT MtPMO9E reveals that a terminal heteroatom of Q157 overlays with Nε of H157. Altogether, the data suggest that H157 is not important for proton transfer, but support a role for H157 as a hydrogen-bond donor to diatomic-oxygen intermediates, thus facilitating catalysis with either O2 or H2O2.

Characterization and DFT investigation of CuWO4@CMC/PVA composite with down conversion ability

This study focuses on the synthesis of CuWO₄ nanoparticles using a simple hydrothermal method and their incorporation into carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) polymer blend through the solution casting method, resulting in CuWO₄@CMC/PVA polymer nanocomposites with varying CuWO₄ concentrations (0.0, 0.5, 1.0, 2.0, and 4.0 wt/wt%). Rietveld refinement of XRD data was performed to assess the phase purity of CuWO₄ nanoparticles and found to possess triclinic unit cells. Furthermore, the microcrystalline properties of the prepared nanocomposites were also evaluated. The surface topography of the CuWO₄@CMC/PVA nanocomposite was examined using AFM to assess its morphological features and surface roughness, while FE-SEM and SEM were employed for microstructural analysis to evaluate the morphology of nanoparticles and their distribution in the polymer matrix. The interaction between the CuWO₄ nanoparticles and the polymer matrix was rationalized using FTIR spectroscopy, complemented by DFT and TDDFT studies. Additionally, thermal properties such as melt properties and thermal stability were investigated through DSC and TGA respectively. While water contact angle measurements were utilized to assess wettability and surface energy. Optical properties such as absorbance, absorption coefficient, energy band gaps (direct and indirect), refractive index, optical conductivity were analysed and found that there was a monotonic decrease in the band gap as the nanoparticles concentration increases. Photoluminescence spectroscopy was used to analyse emission properties to understand the nanocomposites' and potential for photovoltaic and UV-blocking applications.

Formulation, Development and Evaluation of Pulsatile Tablets of Etoricoxib

Aim: This research aimed to develop a pulsatile drug delivery system (PDDS) for etoricoxib, selective COX-2 inhibitor analgesic, to address the limitations of conventional formulations by releasing the drug at specific intervals aligned with the circadian rhythm of pain. Method: Core tablets containing Etoricoxib were prepared by direct compression with varied concentrations of croscarmellose sodium as a superdisintegrant. The optimized core tablets were coated using hydrophilic (HPMC K4M) and hydrophobic (ethyl cellulose) polymers in different ratios to create press-coated pulsatile tablets with varying lag times. Physical properties hardness, thickness, friability, and disintegration, drug content uniformity, and in vitro release were evaluated. Results: The core tablets exhibited rapid drug release, with batch C3 showing 98.61% release within 60 minutes. Press-coated formulations with different polymer ratios exhibited varying lag times, with batch F3 achieving the optimal balance—providing a 4-hour lag time and 96.6% drug release over 8 hours. Stability studies confirmed the physical and chemical stability of the optimized formulation (F3) over 6 months under accelerated conditions. Conclusion: The developed press-coated pulsatile tablets of etoricoxib successfully achieved a controlled lag time and sustained drug release profile, making them suitable for chronopharmacological management of pain. Keywords: Etoricoxib, Pulsatile Drug Delivery System, Chronopharmacology, Press-Coated Tablets. etc

Carbon microspheres prepared from soluble starch hydrothermal carbonization for extending thermal stability of water-based drilling fluid

This study employed hydrothermal carbon microspheres (HCMs) as high-temperature stabilizers in drilling fluids. The HCMs were synthesized through a green hydrothermal carbonization method, using soluble starch as the precursor. The impact of HCMs on the thermal stability of xanthan, polyanionic cellulose and synthetic polymer solutions was assessed by comparing their rheological changes before and after thermal aging. The rheology and filtration properties of a polymer-based drilling fluid in the presence of HCMs were recorded before and after dynamic thermal aging at various temperatures for 16 h and static thermal aging at 200 °C for 96 h. The results demonstrated that HCMs effectively maintained stable rheology and low filtration loss following dynamic hot rolling at various temperatures and prolonged static thermal aging, surpassing the performance of conventional Na2SO3 and nano-SiO2 stabilizers. Mechanistic studies, including dissolved oxygen measurements, free radical detection, and cryo-scanning electron microscopy observations, revealed that HCMs can consume dissolved oxygen, scavenge free radicals, and physically crosslink polymers. This process prevents polymer thermo-oxidative degradation and ensures the stability of the drilling fluid. HCMs are novel, stable, sustainable, and highly effective high-temperature stabilizers for water-based drilling fluids. This study introduces a new application of biomass-derived hydrothermal carbonaceous materials for high-temperature drilling.

Improvement of the properties of nanocellulose suspensions and films by the presence of residual lignin

The effect of lignin on several properties of nanocellulose suspensions and films, such as degree of mechanical fibrillation, optical transparency, and gas barrier properties is still a matter of study. In the present work, it was investigated the influence of residual lignin on the efficiency of cationization and enzymatic pretreatments to produce lignin-containing nanocelluloses (LCNFs) from unbleached kraft pulps, and, on the properties (mechanical, gas barrier, transparency, antioxidant activity and thermal stability) of the corresponding films. The overall efficiency of the pretreatments was not negatively affected by the presence of lignin (3–4 wt%) in the starting pulps, as measured by the degree of fibrillation, degree of polymerization of cellulose, optical transmittance, and cationic group content (cationization). On the contrary, lignin could even enhance the mechanical fibrillation and the optical transmittance (transparency) of the cationic and enzymatic LCNF suspensions compared to the reference lignin-free nanocelluloses (CNFs) prepared from bleached pulp. Lignin could also improve the optical transparency of the films, which is an important finding of the present work: 64.8% for LCNF-Cationic (-Cat) vs. 56.9% for CNF-Cat, and 74.5% for LCNF-Enzymatic (-Enz) vs. 64.5% for CNF-Enz. Moreover, films with lignin demonstrated higher antioxidant activity, UV-light absorption capacity, larger char residue, and even improved oxygen barrier compared to the analogous CNF films. A remarkable oxygen barrier performance was exhibited by the LCNF-Enz film (oxygen transmission rate below 2 cm3/m2.day). Overall, the presence of residual lignin in the cellulose micro/nanofibril production can improve some of the suspension and film properties, particularly the optical transparency.

Dynamic nuclear polarization solid-state NMR spectroscopy as a tool to rapidly determine degree of modification in dialcohol cellulose

Dialcohol cellulose can be prepared by periodate-mediated oxidation of cellulose followed by reduction with borohydride. The two-step reaction creates a modified cellulose polymer which is ring-opened between the C2 and C3 carbons in the glucose unit. This material has attracted both scientific and commercial interest, due to its potential role in the transition towards a fossil-fuel-free society. In order to become a reliable component in the materials of tomorrow, chemical properties such as degree of modification must be accurately quantified. In this work we describe how solid-state NMR spectroscopy, enhanced by dynamic nuclear polarization (DNP), can be used for this purpose. Our results illustrate that it is possible to obtain high sensitivity enhancements in dialcohol cellulose with the DNP enhanced solid-state NMR technique. Enhancements above a factor of fifty, on a 400 MHz/263 GHz DNP system in the presence of 12 mM AMUPol radical were achieved. This allows us to quantify the degree of modification in dialcohol cellulose samples in time spans as short as 20 min using DNP enhanced multiple-contact cross polarization experiments. We also exemplify how DNP enhanced, 13C-13C dipolar recoupling experiments can be used for the same purpose and for studying chemical shift correlations in dialcohol cellulose.Graphical abstract