Upholstered furniture represents a major fuel load in homes, and is often the first ignited item in dwelling fires. Thus, it poses a danger to occupants, especially those who need assistance to evacuate. Improved fire properties of upholstered furniture may delay or prevent the fire development. Hence, available time for occupants to escape will increase. Fire safety measures should be accessible, easily applicable, cost efficient, and without harmful effects on health and the environment. Results from small-scale screening tests and large-scale fire experiments of typical upholstery materials on the Norwegian market are presented. The materials were polyurethane foam covered with three different fabrics: 100% cotton, and two different cotton/polyester blends. The covers were tested untreated, with application of two types of fire retardants, and covered with a thick wool blanket. The test results from a complete armchair show that the simple measures were able to delay the fire growth, where the fire-retardants gave the longest delay. This indicates that the fire behaviour of upholstered furniture may be efficiently improved by application of simple measures. This could be particularly useful in residences where a higher level of fire safety is needed, for example in homes for at-risk persons in case of fire.

The aim of this project was to find new environmentally friendly, and safe flame retardants(FR) from bio-based resources such as agricultural waste. The intended application of the FRs was on textiles. 

Textiles are used in many different consumer products such as clothes, blankets, carpets, bedsheets, and upholstery, and since they are combustible, they will contribute to a large fire load in a room. One way to increase fire safety in homes and public buildings is to use flame retardants. They can delay the onset of a fire, or reduce the rate of fire spread, which gives opportunity for people to extinguish the fire, or escape in time. However, many flame retardants have been banned because they are bad for the health and/or the environment. 

Phytic acid (PA), which is used by plants to store phosphorus, was combined with a few molecules from the group of purines, which are naturally occurring in living systems, and consequently safe. Commonly known purines are caffeine, theobromine, and theophylline, which are found in coffee, tea and chocolate. Other purines are guanine and adenine, which are building blocks in DNA.

Initially, screening tests were performed where PA and different purines were mixed in various ratios and applied on cotton, polyester, or wool. Burning tests and microscale combustion calorimetry (MCC) were used to assess the FR ability. Based on the results from the screening tests, the best mixtures were selected for further testing. The selected mixtures were PA with theophylline (TP) on cotton, and PA with adenine (AD) on cotton and polyester.

In the second phase of the project, the selected mixtures were investigated with cone calorimetry to get information on their heat release properties, and with thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to get more detailed information on decomposition temperatures and processes. Nuclear magnetic resonance (NMR) was used to get additional information on the decomposition processes. Scanning electron microscopy (SEM) in combination with energy-dispersive X-ray analysis (EDX) was used to confirm the presence of both PA and purine on the textile, and to compare the surface morphology before and after FR treatment and burning.

Finally, medium scale fire demonstration experiments with a mock-up chair were performed on the best mixture (PA-AD) on cotton and polyester to validate that the small and medium scale experiments are applicable also in scales that are relevant for end-use. 

The mixtures showed overall good FR performance, but the best result was on cotton. The results from methods where milligram size samples were used could be scaled up to fire demonstration tests. The main mechanism of action for the FR was charring the textile surface to reduce the amount of flammable pyrolysis gases, but the FR also worked by forming gases which dilute the oxygen and thus prevents the burning process. Endothermic reactions, e.g., degradation of the material, cools the material so that it will be more difficult to ignite, and formation of free radicals can stop the pyrolysis gases before they can react with the oxygen. Overall, the result was a self-extinguishing FR. The FR can also easily be applied on a textile by dipping the item in an aqueous solution.

Syftet med detta projekt var att hitta nya miljövänliga och säkra flamskyddsmedel (FR) från biobaserade resurser som jordbruksavfall. Den avsedda tillämpningen av FR var på textilier. Textilier används i många olika konsumentprodukter som kläder, filtar, mattor, lakan och klädslar, och eftersom de är brännbara utgör de en stor brandriskfaktor i ett rum. Ett sätt att öka brandsäkerheten i bostäder och offentliga byggnader är att använda flamskyddsmedel. De kan fördröja uppkomsten av en brand, eller minska brandspridningshastigheten, vilket ger möjlighet för människor att släcka branden, eller fly i tid. Många flamskyddsmedel har dock förbjudits eftersom de är dåliga för hälsan och/eller miljön.

Fytinsyra (PA), som används av växter för att lagra fosfor, kombinerades med olika molekylerfrån gruppen puriner, som förekommer naturligt i levande system och därför är säkra. Allmänt kända puriner är koffein, teobromin och teofyllin, som finns i kaffe, te och choklad. Andra puriner är guanin och adenin, som är byggstenar i DNA. Inledningsvis utfördes screeningtester där PA och olika puriner blandades i olika förhållanden och applicerades på bomull, polyester eller ull. Förbränningstester och förbränningskalorimetri i mikroskala (MCC) användes för att bedöma FR-förmågan. Baserat på resultaten från screeningtesterna valdes de bästa blandningarna ut för vidare testning. De utvalda blandningarna var PA med teofyllin (TP) på bomull och PA med adenin (AD) på bomull och polyester.

I den andra fasen av projektet undersöktes de utvalda blandningarna med konkalorimetri för att få information om deras värmeavgivningsegenskaper, och med termogravimetrisk analys (TGA) och differentiell svepkalorimetri (DSC) för att få mer detaljerad information om nedbrytningstemperaturer och processer. Kärnmagnetisk resonans (NMR) användes för att få ytterligare information om nedbrytningsprocesserna. Svepelektronmikroskopi (SEM) i kombination med energidispersiv röntgenanalys (EDX) användes för att bekräfta förekomsten av både PA och purin på textilien, och för att jämföra ytmorfologin före och efter FR-behandling och bränning. Slutligen utfördes medelstora branddemonstrationsexperiment med en mock-up-stol på den bästa blandningen (PA-AD) på bomull och polyester för att validera att de små och medelstora experimenten är tillämpliga även i skalor som är relevanta för slutanvändning.

Blandningarna visade över lag bra flamskyddsprestanda, men det bästa resultatet var på bomull. Resultaten från metoder där prover i milligramstorlek användes kunde skalas upp till branddemonstrationstester. Den huvudsakliga verkningsmekanismen för FR var att förkolna textilytan för att minska mängden brandfarliga pyrolysgaser, men FR fungerade också genom att bilda gaser som späder ut syret och därmed förhindrar förbränningsprocessen. Endoterma reaktioner, t.ex. nedbrytning av materialet, kyler materialet så att det blir svårare att antända, och fria radikaler som bildas kan reagera med pyrolysgaserna innan de kan reagera med syre. Sammantaget blev resultatet en självslocknande FR som också enkelt kan appliceras på textiliergenom att doppa dessa i en vattenlösning.

Rare-earth elements (REEs) are indispensable in various applications ranging from catalysis to batteries and they are commonly found from phosphate minerals. Xenon is an excellent exogenous NMR probe for materials because it is inert and its ¹²⁹Xe chemical shift is very sensitive to its local physical or chemical environment. Here, we exploit, for the first time, ¹²⁹Xe NMR for the characterization of porous structures and adsorption properties of REE phosphates (REEPO4). We study four different REEPO4 samples (REE = La, Lu, Sm and Yb), including both light (La and Sm) and heavy (Lu and Yb) as well as diamagnetic (La and Lu) and paramagnetic (Sm and Yb) REEs. ¹²⁹Xe resonances are very sensitive to the porous structures and moisture content of the REEPO4 samples. In the samples treated at a lower temperature (80 °C), free water hinders the access of hydrophobic xenon into small mesopores, but the treatment at a higher temperature (200 °C) removes the free water and allows xenon to explore the mesopores. Based on a standard two-site exchange model analysis of the variable-temperature 129Xe chemical shifts, as well as its proposed, novel modification for paramagnetic materials, the average mesopore sizes were determined. The size was the largest (79 nm) for the La sample with mixed monazite (70%) and rhabdophane (30%) phases and the smallest (6 nm) for the Yb sample with pure xenotime phase. The mesopore sizes of the Lu and Yb samples (12 and 6 nm) differed by a factor of two regardless of their similar xenotime phase. The ¹²⁹Xe NMR analysis revealed that the heats of adsorption of the samples are similar, varying between 8.7 and 10.1 kJ/mol. For diamagnetic samples, computational modelling confirmed the order of magnitude of the chemical shifts of Xe adsorbed on surfaces and therefore the validity of the two-site exchange model analysis. Overall, ¹²⁹Xe NMR provides exceptionally versatile information about the pore structures and adsorption properties of REEPO4 materials, which may be very useful for developing the extraction processes and applications of REEs.

³¹P solid state NMR studies combined with DFT calculations were conducted over a chosen series of rare earth element phosphates (REEPO4s), selected on the basis of the size and magnetic properties of REEs (La, Sm, Lu and Yb). PXRD analysis revealed the presence of rhabdophane (La, Sm), monazite (La) and xenotime (Lu, Yb) phases of these phosphate compounds. The direct excitation and cross-polarization ³¹P NMR studies together with calculations confirmed the PXRD results for the abovementioned bulk structures, but also revealed presence of several local phosphorus environments on surfaces. NMR is sensitive to the atomic level local interactions, and we were able to show that the combination of experimental and theoretical NMR methods can provide information unavailable with other methods. Due to the distinct coordination of the water molecules to crystal surfaces with different Miller plane cleavages, we were able to identify from the NMR spectra the surface structures of the studied minerals. This adds to the knowledge of the bulk structures of REE phosphates and provides preliminary data for studies on coordination of various ligands on REE phosphate surfaces. This combination of experimental and computational methods can further be used for studies on surface chemistry, important for applications in catalysis and extraction of REEs from the minerals.

Flame retardants are commonly used as a way to reduce the risk of fire. However, many of the currently used flame retardants are toxic and hazardous to the environment. Therefore, there are incentives to find safer alternatives. In nature, there are many substances that can function as non-toxic and environmentally friendly flame retardants. Phytic acid is the main storage form of phosphorus in plants and can be found in e.g. nuts and cereals. Amino acids are the building blocks of enzymes and proteins. Many common metal ions are important nutrients.

Dicarboxylic amino acid-based surfactants (N-dodecyl derivatives of -aminomalonate, -aspartate, and -glutamate) in combination with hexadecyltrimethylammonium bromide (HTAB) form a variety of aggregates. Composition and concentration-dependent mixtures exhibit liquid crystal, gel, precipitate, and clear isotropic phases. Liquid crystalline patterns, formed by surfactant mixtures, were identified by polarizing optical microscopy. FE-SEM studies reveal the existence of surface morphologies of different mixed aggregates. Phase transition and associated weight loss were found to depend on the composition where thermotropic behaviours were revealed through combined differential scanning calorimetry and thermogravimetric studies. Systems comprising more than 60 mol% HTAB demonstrate shear-thinning behaviour. Gels cause insignificant toxicity to human peripheral lymphocytes and irritation to bare mouse skin; they do not display the symptoms of cutaneous irritation, neutrophilic invasion, and inflammation (erythema, edema, and skin thinning) as evidenced by cumulative irritancy index score. Gels also exhibit substantial antibacterial effects on Staphylococcus aureus, a potent causative agent of skin and soft tissue infections, suggesting its possible application as a vehicle for topical dermatological drug delivery.

A new low-cost and simple synthesis of titanium phosphate functional materials of desired composition has been developed. The route of material transformation is unconventional solid precursor-sorbent-anode material. The synthesis is based on the heterogeneous interaction between phosphoric acid and the solid (NH4)2TiO(SO4)2·H2O precursor. The influence of the synthesis conditions on the titanium phosphate composition has been thoroughly studied using NMR, FTIR spectroscopy, XRD, and DTA techniques, and mechanism of TiP formation has been established. Optimal synthesis conditions to provide obtaining of a pure TiO(OH)(H2PO4)·H2O (TiHP) phase have been found. In contrast to existing methods that require rigid synthesis conditions and high reagent consumption, the new synthesis lasts 4 h and no special equipment is needed. The sorption and electrochemical capabilities of TiHP have been investigated. The obtained material exhibits the highest sorption capacity toward Cs+ and Sr2+ ions among other TiP-based ion exchangers. Furthermore, TiHP has been tested as a sorbent for treatment of multicomponent liquid radioactive waste and distribution coefficients of the radionuclides have been found to be 105 mL·g–1. New approach to the synthesis of precursor for Li-ion batteries has been proposed. The substitution of protons of the dihydrogen phosphate group in TiHP by lanthanum (III) cations and subsequent calcination at 900 °C result in formation of nanoparticles of the final powder and provide the good electrochemical characteristics of obtained electrode material.

We report on syntheses, characterisation by nuclear magnetic resonance (NMR) spectroscopy, X‐ray diffraction (XRD) measurements, and density functional theory (DFT) calculations of electronic/molecular structure and NMR chemical shifts of complexes of Bi(III), having the molecular formulae: [Bi{S₂CN(C₂H₅)₂)}₃] (1), [Bi{S₂CN(C₂H₅)₂)}₂(C₁₂H₈N₂)NO₃)] (2), and [Bi₂{S₂CN(CH₂)₅}₆ H₂O] (3). The powder XRD patterns of complexes (1) and (2) resembled the corresponding calculated powder XRD patterns for previously reported single crystal structures. Single crystal XRD structure of complex (3), reported in this work, adopted an orthorhombic system with a space group Pbca with a=10.9956(3) Å, b=27.7733(8) Å, c=35.1229(10) Å and α=β=γ=90°. The experimental solid‐state ¹³C/¹⁵N NMR data of the complexes (1)‐(3) were in accord with their X‐ray single crystal structures. The unit cell of the complex (3) shows a weak supramolecular Bi S interaction leading to the formation of a non‐centrosymmetric binuclear molecule [Bi₂{S₂CN(CH₂)₅}₆ H₂O], which displays structural inequivalence in both ¹³C/¹⁵N NMR, and XRD data. Assignments of resonance lines in solid‐state ¹³C/¹⁵N NMR spectra of complexes (1)‐(3) were assisted by chemical shift calculations using periodic DFT methods. The findings of the present multidisciplinary approach will contribute in designing molecular models and further understanding of the structures and properties of (diamagnetic) metal complexes, including heavy metal ones.

Development of sustainable flame retardants for cotton-based materials has become an active research interest as many of the currently used flame retardants are harmful both to the environment and to human health. Phytic acid is a natural resource that has shown potential to be an environment-friendly flame retardant. In order to design highly efficient flame retardants based on phytic acid, detailed knowledge of the decomposition process is essential. In this study, cotton samples were prepared with pure phytic acid, as well as salts of sodium or calcium ions. All samples improved the fire performance, most notably sodium phytate, as shown by a simple burning test, as well as by thermogravimetric analysis. The formation of char prevents the degradation of cotton, leaving a residual mass. Phosphorus-31 nuclear magnetic resonance spectroscopy was used to characterize the intermediate products formed during the pyrolysis process. Both phytate salts polymerize, sodium to a higher degree than calcium.

Phosphorus based flame retardants are considered to be the best for cellulose-based materials such as cotton and wood. A non-toxic naturally occurring substance with high phosphorus content is phytic acid, which is used by plants as the main storage of phosphorus. It is prevalent in grains and seeds, so we eat it every day. Phytic acid and phytate complexes with various common and non-toxic metal ions or ammonia have been studied on cotton and wood in orderto systematically assess their performance as flame retardants and elucidate their mechanismsof action.

Simple combustion tests have been used to gain a first overview of the relative performance of the flame retardants depending on which ion is combined with the phytic acid, and in which proportions. Analytical methods such as TGA and calorimetry have been used to investigate the thermal properties and thermal degradation of the samples. Spectroscopic techniques suchas MAS NMR have been used to explain the chemistry behind the thermal degradation mechanisms in molecular detail. The main focus has been on cotton samples, but an efficient methodology to control the humidity of wood samples in lab scale has been developed for future investigations on wood.

Phytic acid and its complexes have a flame retarding effect on both cotton and wood. The thermal process is similar on both materials. The mechanism is low-temperature charring giving less combustible degradation products, followed by cooling polymerization of the phosphate groups in the phytic acid, and formation of a second barrier to prevent the mixture of combustible volatiles and oxygen. It is important to have ionizable protons available in the flame retardant to induce the main mechanism of charring. Cone calorimeter tests on cotton samples show that the samples self-extinguish. Sodium phytates have a better performance than calcium phytates, as shown from combustion tests and FIGRA index on cotton samples. Possibly the superior flame retarding effect of sodium compared to the other ions is because ofthe radical quenching ability of alkali metals, but further investigations are needed into thisissue.

Some of the results are also available in Bachelor and Master theses, and in a recently accepted paper in Green Materials Special Issue on Sustainable Flame Retardants.

The results may be of interest to the scientific community as well as for companies and organizations that work for a fire-safe and sustainable living environment.