title: Characterization of synthetic and commercial trisiloxane surfactant materials

authors: Bonnington, L. S.

subjects: organosilicone surfactant

abstract: The organosilicone surfactant Silwet L-77® (L-77), used as an agrochemical adjuvant, is a mixture comprised predominantly of [(CH₃)₃SiO]₂ (CH₃)Si (CH₂)₃ (OCH₂CH₂)n OCH₃ oligomers (n = 3-16, average n  7.5). The commercially available L-77 mixture was purified by reversed-phase high-performance liquid chromatography (HPLC) to obtain individual trisiloxane surfactant components. Pure oligomers (n = 3, 6 and 9) were also synthesized. Synthesis was achieved by hydrosilylation of monomeric ethoxylate monomethyl ether starting reagents. Pure hexa- and nona-ethylene glycols were produced by condensation of smaller oligomers. Atmospheric-pressure ionization mass spectrometry (MS) methods were used to characterize fully the commercial L-77 product and synthesized or isolated components. The application of Fourier-transform ion cyclotron resonance MS and online HPLC-electrospray ionization MS techniques to the analysis of this surfactant are described here. The application of these analytical techniques also enabled elucidation of the synthetic by-products present in the commercial formulation.

text: Characterization of synthetic and commercial trisiloxane surfactant materials The organosilicone surfactant Silwet L-77® (L-77), used as an agrochemical adjuvant, is a mixture comprised predominantly of [(CH₃)₃SiO]₂ (CH₃)Si (CH₂)₃ (OCH₂CH₂)n OCH₃ oligomers (n = 3-16, average n  7.5). The commercially available L-77 mixture was purified by reversed-phase high-performance liquid chromatography (HPLC) to obtain individual trisiloxane surfactant components. Pure oligomers (n = 3, 6 and 9) were also synthesized. Synthesis was achieved by hydrosilylation of monomeric ethoxylate monomethyl ether starting reagents. Pure hexa- and nona-ethylene glycols were produced by condensation of smaller oligomers. Atmospheric-pressure ionization mass spectrometry (MS) methods were used to characterize fully the commercial L-77 product and synthesized or isolated components. The application of Fourier-transform ion cyclotron resonance MS and online HPLC-electrospray ionization MS techniques to the analysis of this surfactant are described here. The application of these analytical techniques also enabled elucidation of the synthetic by-products present in the commercial formulation.

year: 2004

title: Book review: GEORGES MINOIS: The Atheist’s Bible: The Most Dangerous Book That Never Existed.

authors: Simms, Norman

abstract: This article reviews the book: “GEORGES MINOIS: The Atheist’s Bible: The Most Dangerous Book That Never Existed.”

text: Book review: GEORGES MINOIS: The Atheist’s Bible: The Most Dangerous Book That Never Existed. This article reviews the book: “GEORGES MINOIS: The Atheist’s Bible: The Most Dangerous Book That Never Existed.”

year: 2013

title: The intergenerational perpetuation of achievement messages in whānau

authors: Southey, Kim Marie

subjects: Maori

abstract: The current research is an open exploration of achievement messages that are carried from generation to generation in whānau, in relation to the mainstream education system of Aotearoa. Participant groups comprised of two to three generations within each whānau. A maximum of eight whānau will be asked to participate. A series of continuous conversations will be held with each member of the whānau, reminiscent of the narrative approach, but most recently described as a methodology that allows for ensuring that data is collected in its fullest form.
Differing views about achievement and how it is negotiated within whānau will be explored; along with issues on what, and who, within whānau are the most predominant indicators of achievement views. Detracting from an ethnocentric view of scholastic ability (a common marker for achievement) is done through abandoning mainstream ideals. This research favours an open exploration approach allowing for differing values about what constitutes achievement, and what context achievement is based in. Outcomes of the research are intended to show patterns within whānau and among Māori on the mainstream school system, and how this system has contributed to achievement messages. The positive or negative nature of the contribution from mainstream education is highly important and relevant to further research goals, including the ability to use outcomes to suggest social change in education provision for Māori.

text: The intergenerational perpetuation of achievement messages in whānau The current research is an open exploration of achievement messages that are carried from generation to generation in whānau, in relation to the mainstream education system of Aotearoa. Participant groups comprised of two to three generations within each whānau. A maximum of eight whānau will be asked to participate. A series of continuous conversations will be held with each member of the whānau, reminiscent of the narrative approach, but most recently described as a methodology that allows for ensuring that data is collected in its fullest form.
Differing views about achievement and how it is negotiated within whānau will be explored; along with issues on what, and who, within whānau are the most predominant indicators of achievement views. Detracting from an ethnocentric view of scholastic ability (a common marker for achievement) is done through abandoning mainstream ideals. This research favours an open exploration approach allowing for differing values about what constitutes achievement, and what context achievement is based in. Outcomes of the research are intended to show patterns within whānau and among Māori on the mainstream school system, and how this system has contributed to achievement messages. The positive or negative nature of the contribution from mainstream education is highly important and relevant to further research goals, including the ability to use outcomes to suggest social change in education provision for Māori.

year: 2003